Boom Zoom - A Lifter Love Affair

[ForkliftCertified (Rob Weston)]

Hi all, I figured it was about time I finally sat down and wrote a proper build diary. For those of you that don’t know, this is Boom Zoom, my 4 wheel drive lifter beetleweight robot:

But it didn’t always look like this. Below I’ll be documenting the design, build and iteration process for this little guy, from my very first combat robot put together with a hacksaw, drill and very little clue to the current version, made using lots of 3D printing, CNC machining and lasercutting. I’ve learned a lot in my time developing this robot, and I hope some of that helps you in your own designs

[Jack (Jack Franklin)]

[ForkliftCertified (Rob Weston)]

It’s finally here! Sorry about the wait, been a busy few weeks.

Boom Zoom MK1

Back in late 2021, I was bored out of my mind. The pandemic was still in full swing, and in my desperation for something to do I stuck the reboot series of Robot Wars on. I quickly became hooked, and after consuming all Robot Wars content I could find, moving onto Battlebots and after exhausting all avenues there, I found the BBB Beetleweight event videos. Building one of these machines looked achievable even to someone like myself with no marketable engineering skills or background, and after doing some further research (Read: Watching Craig’s excellent breakdown of Snappy, and listening to Spinnerproof as they went from fans to builders) I felt ready to build my first robot! But what to build…

While watching Battlebots I’d slowly but surely fallen in love with Whiplash. The way it bullied opponents around, grappling and lifting them with ease really appealed to me. It seemed able to match even the scariest robots of its time without having the same level of offensive weaponry as a lot of them, instead relying on driving skill and tenacity. This was right after season 5 aired, and the version they ran without a spinner during the fights with Valkyrie was fresh in my mind. Scaling something like this down to 1.5kg seemed very doable, so I opened up Sketchup and after a few nights of effing and jeffing, had something vaguely resembling a robot! But what should I call it? As some of you may know, I grew up on a dairy farm, and I wanted to pay homage to this by incorporating it into my robot. I ended up going with the name Boom Zoom, which is a shorthand name for a telehandler. What’s a telehandler? Well they look like this. I hope the reason for the name is pretty obvious.

I set myself a few challenges when designing it: It had to be fast, durable, and invertible. I wanted something that would put on an entertaining fight, even if that meant taking a beating. To that end I went with a 650mah 4S LiPo battery, 4x BBB 22mm brushed gearmotors and mounts (one for each wheel), 2x BBB Brushed ESCs (V1), an FS2A receiver, BBB 3A BEC, and a generic 30KG/CM servo off Ebay for the weapon. The link was an XT60 mounted with the BBB link mount kit, with some 30A fuse wire in the link itself. I used M4 woodscrews for the majority of the construction, with M4 bolts holding the lid on using nutstrip. The wheels were 3 inch Fingertech foamies held on with aluminium twist hubs, and the titanium forks and aluminium servo mount were also from Fingertech. For the weapon, I used a brass cabinet hinge for the pivot point on the lifter, and for the weapon mechanism I used the same loose linkage as Snappy, with a piece of HDPE mounted to the servo horn pushing against the lifter without being rigidly attached to it, and some elastic as a return mechanism. This was simple to engineer and would protect the servo a lot better than a more rigid mounting system. I used a mix of black 5mm and green 10mm HDPE for the construction of the chassis.

To be blunt, it was a mess. I’d not put the slightest thought into how the robot would fasten together, and I hadn’t added a single fastener or hole for one anywhere on the model. The side rails were 5mm HDPE, and the entire thing was ginormous for a beetle. That being said, it was my first go at this whole robot thing, mistakes were gonna be made. Anyway, time to build it!

I started with a cardboard mockup of the chassis to get a feel for the dimensions, then marked out the dimensions of the panels on my HDPE stock with a sharpie, set square and ruler. I cut the pieces with a hacksaw, and cleaned them up using a file, sandpaper and a wood plane. As with most things cut with hand tools, nothing quite lined up, so plenty of extra fettling was needed to get it all to go together. For the holes I marked out the center points with a sharpie, then center punched them and drilled them with a cordless drill. For the motor holes I used a 22mm Forstner bit. With basic hand tools it was hard work, but the bulk of the chassis was cut and assembled in a couple of weeks!

Once the chassis was together, the electronics needed soldering up. I hadn’t soldered anything since secondary school, but the BBB wiring guide and a little help from some other builders online made it a cinch. I did end up cutting the wires much too long, but the chassis was big enough to make this not really a problem. I also put the motors on XT30 connectors, to make swapping them out easier in the event of them getting mulched.

For any robot to pass a tech check it needs a few things, so I fashioned some sharp edge protection out of whiskey corks, drilled a locking bar hole for the lifter into which slid a steel rod, and made a cradle out of an old Playstation 1 game, Sabrina the Teenage Witch: A Twitch In Time! This would be my cradle for around 2 years, and had the game in the case the entire time.

I ended up adding a few details I’d never bothered to CAD, such as some struts to mount the front armour and some extra armour/bracing panels on the lifter, then finished it off with some snazzy decals! I also took the time to loctite every screw, secure the connectors with cable ties and apply some liquid latex to the wheels. Overall, I was pretty happy with the result! In testing it was fast, invertible, could overturn another beetleweight, self-right, and push quite well.

With the robot all finished, there wasn’t anything left to do but enter it into a competition! I ended up choosing BBB’s 2022 Beetle Brawl, and was lucky enough to snag a spot. Flash forward to the day of the event, after a very nervy morning I made it through safety without any issues.

BBB Beetle Brawl 2022 - Full Competition - Bristol Bot Builders Beetleweight Combat Robots

Here’s the fight video for the event, if you want to see them my fights are at 16:27, 43:04 and 1:05:07.

I’ll spare you the nitty gritty of each fight and focus on my takeaways from them. In my first fight I found myself dominated by Enigma, with its much better ground game making frontal attacks a non-starter. Enigma was also extremely well driven, meanwhile between my big wheels and very sensitive steering I found it hard to stay squared up and I ended up oversteering quite a lot. I was happy to get some half-lifts in during the fight, plus a self-right and a wiggle free from a very precarious situation near the OOTA zone. Ultimately though my inexperience showed, and ended up down the pit thanks to Enigma forcing a driving error from me. Still, my robot was in one piece, and I had a redemption fight ahead of me!

In my second fight I was able to get under Disorder from the sides pretty well, and my beefier drive setup let me out-push, overturn and pin it pretty nicely. I was going for the OOTA but didn’t quite have the angle or the leverage to pull it off, so I settled for immobilizing it instead. Not a lot more to say about this one, I was buzzing to get my first win on the board and again not take any damage, anything else was a bonus at this point!

My third fight was quite an eye-opener. This is the first time I’d fought a spinner, and while there are plenty more powerful weapons out there than Gertrude’s it was more than enough to basically write off this version of Boom Zoom. For starters, it ripped off a piece of front armour which wasn’t great. 3 M4 wood screws clearly isn’t enough to withstand a horizontal spinner, and the threads were pulled out on all 3 mounting holes. My wheels were also chewed to hell, and 2 of my motors separated from their gearboxes from the force of the hits. The hits to the lifter also managed to snap the elastic, disabling the weapon return, and shear the screws holding some of the arm together. The hits to the side where the front was torn off managed to hit the exposed front edge of the 5mm frame rail, buckling it as well. Clearly the robot wasn’t cut out to fight spinners, especially horizontals like Gertrude. I was very happy however to be able to take the fight to a judge’s decision, it showed I’d built something at least sturdy enough to put on a good show, which is a moral victory if nothing else!

Much to my surprise, at the end of the day Boom Zoom ended up winning Best Newcomer! I was over the moon at this, and it’s safe to say I was absolutely hooked on fighting robots. I met a lot of lovely people that day who would go on to be great friends too. On the train home I was already writing a list of ways to improve the robot, but I’ll go into that when I write about Boom Zoom MK2, hopefully this next post won’t take as long!

[Strang_H (Henry Strang)]

You’re telling me this guy Booms and Zooms???

Great writeup bud. Really interesting to see how we both came to Beetles in the same way - Snappy breakdown and a bit too much Spinnerproof for any sane individual.

The space inside BZ V1 is insane, I reckon you could fit a decent antweight comp in there

[Kraken4me (Alex Revell)]

Didn’t Boom Zoom go to robot rebellion (or some event of a similar name)? I may have seen a video of it there.

[ForkliftCertified (Rob Weston)]

Yep! Boom Zoom has been to Robot Rebellion 2022, 2023 and 2024. If you saw it in a video that was probably the 2023 version, I’ll be getting to that one in a later post

[T_Y (Thomas Yau)]

It’s cool seeing the original Boom Zoom, I’m much more familiar with your more recent iterations

[hhills (Harry Hills)]

Hah, Craig’s video and spinnerproof to get me though night shifts (ironically occasionally operating a telehandler) brought me back to beetles. Love that’s a shared experience.

Just want to say as much as we all want to see content, please do take your time. Boom Zoom and its evolution (and the success that has come along with it) is a poster child for How To Do Robots Good with the deliberate ramp up in technology and skill version to version. I can see it as an excellent case study to wave at new builders.

[ForkliftCertified (Rob Weston)]

Howdy all, finally had a free weekend so getting this next part written up wasn’t too bad! Thanks for all the kind words so far, wild how many of us took such similar roads to get here Without further ado:

Boom Zoom MK2

So following on from Boom Zoom’s first event, I decided to shelve MK1. It had taken an absolute beating, and I had quite a few changes I wanted to make. Rather than retrofitting these onto an already knackered chassis, the easiest course of action would be to start fresh. My list of changes included:

1. Modular front attachments including forks and a wedge

2. Better ground game

3. Sturdier front armour

4. Make the whole robot easier to work on

5. Thicker frame rails

I also went about designing and building this version in a completely different way to the last one. I hated using Sketchup, and it ran terribly on my machine. On the advice of a few other builders I made the jump to Fusion 360 as my CAD software of choice. Like Sketchup it was free, but it seemed a lot more powerful and was much more widely used by roboteers. I was recommended the excellent series of tutorial videos by David Small, where he shows how Fusion’s tool suite can be applied to combat robot designs.

How to Use Fusion 360 to Design a Combat Robot (Foxic CAD-A-Long: Part 1)

By following this tutorial, then adapting these techniques to my own design, I was able to CAD the new version of Boom Zoom in a little under a week! I found working with Fusion difficult to get my head around at first, with the sketch and extrude method of design being a big departure from how Sketchup generates shapes. That being said, by the end of this design I was a lot more comfortable with the program, and for anyone looking to get into CAD I’d highly recommend skipping Sketchup and jumping right into Fusion with David’s tutorial. Anyway, here’s what I ended up with:

First things first, I opted to change the colour scheme to match the farming theme of the robot! My family have always gone with John Deere machines, from tractors to lawnmowers and everything in between, and no other robots were rocking this combination of colors at the time. This would go on to become my default colour scheme for all future robots. It’s nice to have a brand I guess.

Getting back to the design itself, this was already a big improvement over my first stab at CAD, as I actually had holes for fasteners this time around! In terms of design changes, I upped the side rails to 8mm HDPE, and dropped the back down to 8mm to match. I also added a full 8mm mount plate behind the front armour, the intent being that the hole pattern on this plate would support multiple front armour packages. For the default front armour I chose 2mm Grade 5 titanium, as this offered great strength for its weight and can be worked with basic power tools. For the wedge configuration I went with a 25mm piece of HDPE cut diagonally to form the angle of the wedge. For making this version I invested in a couple of power tools to make the process easier, namely an angle grinder and circular saw for cutting the titanium and HDPE respectively.

To make life a little easier, I printed 2D profiles of each panel I was cutting onto a sheet of A4, then cut these out, stuck them to the HDPE and used them as templates to cut/drill around. Between this and using the circular saw, this chassis came together much more quickly. Only once it was all together did I realize I had an issue - I’d messed up one of the motor holes, and now only 3 wheels were on the ground at any one time. This was because I’d drilled the holes with a hand drill, and one hole was at a slight angle. To fix this going forward I invested in another tool, a drill press to ensure straight holes, and recut this panel. Using the drill press to make the holes worked a lot better, and soon I had a fully together chassis with all 4 wheels on the ground.

The next step was to cut the titanium! I used the same method of printing 2D profiles straight from the CAD model and gluing them to the ti, then cutting them out using my angle grinder with a cutoff disc. I then used a flap disc to clean up the pieces, and a center punch and tungsten carbide drill bits to bore out the mounting holes.I mounted these to the chassis with M4 bolts and nylock nuts, with a few rubber washers between the armour and chassis to provide some shock absorption.

For the forks, I sent a dxf of the 2d profile I wanted cutting over to Sion, who was kind enough to hook me up as part of a group order with KCut. The forks were waterjet cut out of 4mm Hardox, and with a little dremelling ended up fitting very nicely. The mounts are designed to be easy to make, disposable and ablative, as well as having downward travel limits built in to prevent the forks folding under the robot and immobilizing it.

I then cut the wedge, once again with the circular saw. I wasn’t entirely happy with how these came out though, as the wedge was way off the ground and I thought it’d leave the robot vulnerable to undercutters or horizontals with ground game of their own. I got around this by designing an alternate wedge config out of 6mm HDPE, with a hinged element that rested on the floor.

At this point, the chassis was about done but looking a little drab. I took it apart and began spray-painting, first doing a coat of gray primer, then green and yellow over the relevant parts. I gave the twist hubs for the wheels a coat of yellow as well for good measure. Overall I was pretty happy with the effect, but found the paint flaked off the HDPE very easily, even during gentle handling of the robot. I finished the cosmetics by adding a big John Deere logo vinyl sticker and the name of the robot along the lifting arm, both cut by my partner.

For the electronics, I cut out the core of my previous wiring and replaced it with a BBB breakout cable, with every single part of the robot on some kind of connector to make swapping them out easier. I also swapped out the battery for a smaller 4S 450mah pack, saving a few grams over the old one.

With all this done and the robot together, it was time to snap a few beauty shots:

I already had an event in mind for Boom Zoom MK2: Rapture Gaming Festival. This is seen as one of the biggest events of the beetleweight calendar, and usually attracts a very high standard of robot. Given the fact my last robot had been written off by the very first spinner it faced I was a bag of nerves going into this one.

Rapture Gaming Festival 2022 Robot Rebellion - All Fights - Beetleweight Robot Combat

Anyway, here’s how it went. My fights are at 1:18, 23:57, 50:49, 1:55:29, 2:38:03, and 2:55:15. The new forks worked well against Brug, This Is Not A Drill and Rust In Pieces, allowing me to manoeuvre them around and overturn them successfully. My fight with TINAD in particular was a fantastic driving match and a tense JD, with my drive starting to lock up towards the end of the fight. I later found out this was due to the twist hub working its way down the motor shaft, causing the wheel to rub against the chassis. This was easily fixed by moving the hub back down the shaft and re-tightening the set screw. My fight against Let The Good Times Stroll worried me, it had an insanely powerful weapon that could knock out a robot in one hit if it got a good connection. I got very lucky in Stroll not being able to move forward properly, allowing me to pin it against the wall and overturn it, bending the weapon assembly and causing a massive ESC fire which won me the fight! I was surprised my 30KG servo could handle overturning a 2KG robot like Stroll, and elated to have won my heat without taking any damage!

My round of 16 fight was against Night Fury, and here is where I encountered the first problem with my modular fronts: they took FOREVER to swap. Removing and redoing 6 nylock bolts per side took an absolute age on my own, thankfully Andy offered a hand with his electric screwdriver which sped up the process immensely and meant I was ready in time for my fight. Fat lot of good it did me! Night Fury’s sharp, thin blade cut through my HDPE wedge like butter, got around to my side and took out an entire drive side, exploding the motors with direct hits to the wheel hubs. Getting beached on my own shredded wheel and counted out was a mercy really, and once again a horizontal spinner had completely outclassed Boom Zoom.

This time though the bot was not written off! I was able to swap out the ruined wedge, wheels and motors and get the robot back together in time for a 10 robot rumble to close out the day. This was a weird one, for starters the lifter elastic came undone almost immediately, then a short way into the fight my robot seemed to kind of die when gently pushed into a corner. It’d continue to twitch and briefly respond to input at points, but it was effectively immobilised. The robot worked fine after unplugging the link and plugging it back in, and I’ve never had this issue again with any of my robots. Things went from bad to worse when BFM landed on top of Boom Zoom, snapping the lifter arm in 2 places and knocking the servo loose from its mounting bracket. This damage was catastrophic for this version of the robot, and would require an entirely new lifting arm as well as replacing several other damaged components from the rumble.

For this reason I decided to once again go back to the drawing board and redesign the robot, but this time I’d been chatting with loads of builders at the event, getting pictures of the insides of their bots and making notes of ideas I’d like to try in my own build. I was very happy with how MK2 had performed, all the changes I’d made since MK1 had played a part in making it a better robot (except maybe the wedge) but I had a clear vision of the direction I wanted to go with the robot and felt ready to take the next step in its development. Tune in next time for what I consider the single biggest step up in this robot’s development cycle: Boom Zoom MK3!

[ForkliftCertified (Rob Weston)]

Hey All! The build log for these next versions will be considerably longer as each version competed in several events, with numerous smaller changes taking place between these.

Boom Zoom MK3

Once again a new version of Boom Zoom had basically been written off after its first event, which was getting pretty tiring. I really wanted to take whatever came next to a level where it could survive multiple events without needing a rebuild. I’d been chatting with loads of builders at Robot Rebellion 2022, and decided to steal a load of the best ideas they’d had (and add a few of my own) for Boom Zoom MK3. The biggest changes were:

1. A much smaller, CNC machined chassis.

2. 3D printed TPU front armour and wheelguards.

3. Ditch the foamies for cast polyurethane wheels.

I went with a CNC’d chassis to ensure it would go together first time, with none of the errors that come with a hand cut chassis. It also makes fabricating spares much easier, and makes the whole build process much less labor-intensive. This was also the reason I wanted to try 3D printed armour, as well as being able to iterate on these much more easily than any other manufacturing method.

Only one problem: I didn’t know how to actually make any of this! Still, first things first, time to design the thing. I jumped back into Fusion 360 and before long had something I was pretty happy with.

As you can see, this new version was absolutely tidgey compared to the old one, making it pretty normal sized by average beetle standards. The Ti front panels are gone and the new TPU fronts are secured via a single M5 nut and bolt through 2x10mm bulkheads, which makes swapping out front armour packages incredibly easy. TPU has also been used for the top panel in the lifter, with a 4mm RAEX 400 steel panel on the front to eat the hits from those mean spinners. This version is also much more forky, featuring a grand total of 6 (count em, 6!) forks also made from 4mm RAEX 400. I decided against painting this version (except the RAEX bits) and instead of HDPE went with RG1000 for the green plastic and PE500 for the yellow plastic.

Not having a CNC router of my own at this point, the chassis was cut by the lovely Mr. Strang and even came with sweeties!

A few last bits were hand-cut by myself such as an 8mm back panel and a couple of spacers between the front bulkheads, but even with these it went together like a dream! I was really happy with how this came together, it looked so much cleaner than my hand builds but still had some of that element of high-functioning jank they’d so proudly displayed.

For the TPU I did decide to take the plunge and buy a 3D printer of my own. I went with a Sovol SV01 Pro, which is effectively an Ender 3 with some upgrades like a bigger bed, auto leveling system direct drive extruder. After some dialing in and messing with the slicer settings, it was pooping out pieces without a care in the world!. Alongside the other bits you can see on the robot I also got some wedge designs printed, though these never saw combat.

For the wheels I basically followed Just Cuz Robotics’ excellent guide on cast wheels:

How to Make Custom Wheels for Your Robot - Molding/Casting Polyurethane

I designed a 3D printed core with lots of keying features for the cast polyurethane to wrap around and grip, along with a mould for the wheel core to sit in during casting. I then printed a set of prototypes out of PLA-ST, greased up the moulds with vaseline and cast the wheels using Vytaflex 40 Polyurethane and a small amount (1% of the total mixture) of black dye. I mounted these wheels on Pololu universal mounting hubs.

I found demoulding the wheels to be a total pain and ended up having to cut the wheels out of their moulds with a hacksaw, so I decided on swapping to TPU moulds and wheel cores for future attempts.

For the lifter retraction I wanted something a little more stable than a length of elastic, so I popped into Claire’s and picked up a pack of hairbands. I secured these with zip ties, reasoning that a closed loop of material would be less likely to pull through its mounting hole or snap like the old elastic was prone to.

Very little in the electronics was changed from MK2, the only change of note being swapping from an XT60 to an XT30 for the link. I also added magnets to the base of the robot to improve traction, along with the new grippy wheels I was hoping this would absolutely bully other robots around on a steel floor.

I finished off by adding the customary John Deere decal and printing some optional top armour, and just like that, the robot was done! I took it for a spin at Robonerd Pinball 2022 with some 3D printed standins while I waited for the metal order to arrive and was very happy with how it did, even if I did drive it into the pit!

RoboNerd Pinball - Boom Zoom

After Robonerd I replaced the wheelguards with some bulkier ones with bumpers to prevent getting stuck on its side, and fitted the metal parts once they arrived. With that it was time for Boom Zoom MK3 to see combat, which it would first do at BBB Champs 2022!

BBB CHAMPS 2022

BBB Beetle Champs 2022 - Full Competition - Bristol Bot Builders Beetleweight Combat Robots

BBB Beetle Champs 2022 - Whiteboard Fights & Awards - Bristol Bot Builders Beetleweight Robots

My fights are at 0:00 and 36:50 in the first video, and 6:55 in the second video.

For my first fight I was drawn against Toxin and Keith the Teeth. Not knowing what Keith was but scared it was some kind of crusher, I slapped my top armour on as a precaution. The fight itself went about as well as it possibly could have, with Boom Zoom knocking out both opponents within a minute.The TPU armour stood up well to the hit it took from Toxin, and the robot was good to go again with basically no repairs! Next up was End Boss, which was pretty much the worst draw possible for me. End Boss spent most of the match outreaching Boom Zoom’s forks and bouncing it off the roof, with a particularly nasty shot bending the baseplate and knocking the servo free from its mounting brackets. The weapon still partially worked even with the servo dislodged, well enough to act as a self-righter anyway. I did at points take the fight to End Boss and managed a pin and lift onto my own lid, but thanks to the dislodged servo I couldn’t convert this lift to a grab, End Boss wiggled free and I ended up pitting myself. Crud.

The damage from this fight was pretty gnarly, aside from the baseplate and servo damage the front armour was looking majorly worse for wear, and half a wheelguard had been completely ripped off. The forks were also varying degrees of bent and chipped, but honestly this was all fixable! I replaced the front armour and forks with spares, bent the servo bracket and baseplate back into shape with some pliers and reseated the servo, and just like that I was ready for a whiteboard!

Some very scary spinners in this one, but once again Boom Zoom held up well against them, getting some more good lifts and what was probably my proudest moment of the day, pushing 3.5 kilos of robot from one side of the arena to the other! Winning this one was a nice way to end the day. I felt had the draw been a little kinder I could’ve gone further in the main competition, but was still happy with the robot’s overall performance, and happier still it had actually survived without too much damage! The cherry on the cake was the “Most Improved” award that Boom Zoom walked away with, I’d really gone for it with this version of the robot and it meant the world to see that recognised.

Overall the changes held up great! The printed armour and mounting was a big success, both in terms of maintainability and durability. The new forks did their job, the lifting arm and elastic took several shots from verts without failing, and the tyres and magnets gave it a heck of a lot of push. For once I wasn’t staring down the barrel of a total rebuild after the event, which was a huge relief, but I still had some changes I wanted to make.

First up, I wanted a setup to fight drums and egg beaters with. In that last whiteboard, Bakugo had bent up a couple of forks pretty badly, so I wanted something a little more suited to fighting that kind of wide weapon. I went with this wide “claw” design, the idea being that the radius of the fork’s curve was bigger than that of a standard Fingertech Beater Bar, so all a weapon that size could do is grind against this surface without biting properly. Sadly I didn’t have time to get these cut out of metal, so some hastily printed TPU substitutes would have to suffice. I also thickened up the wheelguards so they wouldn’t be torn off as easily.

Battle In The ‘Burgh 2

Before I knew it, it was time to fight again! This time I made the long trek up to Scotland to compete in Battle in the ‘Burgh 2. This was my first time taking largely the same robot to its second event, and boy was it nice not having to rebuild this thing in the month between BBB and Burgh. It was also a good opportunity to learn a bit more about this design, 3 fights, none of which went 2 minutes isn’t a good sample size and this being a 2-day event had the promise of a lot of arena time.

BITB2 - Fight Night Round 1

BITB2 - Fight Night Round 2

BITB2 - Fight Night Round 3

BITB2 - Top 16

My first 4 fights are timestamped, skip to 27:50 of the third video for my play-in rumble.

BITB2 - Saw Loser Bounty

My Bounty Hunter fights are at 0:00, 1:53 and 4:20.

In my first fight against Uplift, a couple of fatal flaws in the robot were revealed. First off, the new anti-drum attachments were ripped apart. I’d put these on as the claw shape would allow me to control the high front end of Uplift’s chassis easier, but instead they were just shredded by the spinner. To make matters worse, I found that if Boom Zoom was knocked upside down with the lifter open it would become stuck in that position. The hairband didn’t have enough strength to retract the lifter from this position, and I was quickly counted out. Nuts.

I swapped out the mangled front for the default forks when I fought Panthor, and was very happy with how I performed. The magnets seemed to really like the floor in Shane’s arena, and the robot moved like it was on rails. I was able to bully Panthor around for the most part, but it did land a couple of solid shots before its weapon gave up the ghost. Despite this I was able to stack the robot awkwardly and narrowly get it counted out.

For 7th Circle it was much of the same, however I found myself losing the ground game more often than not once again, and getting popped into the air for my troubles. Once again that retraction problem reared its head, and I was left stuck upside down and counted out. The damage from this one was pretty tasty, another drive motor had come away from the gearbox, 7th Circle exploded a couple of my magnets which created some pretty sparks, and completely “fishhooked” a fork, bending it beyond the point of recognition. The repair job was majorly rushed for this, as Boom Zoom still had a shot at the top 16 by entering a rumble!

After scraping through the rumble without too many issues I once again was drawn against Uplift in the round of 16. I was a lot more cautious in this fight, attempting to go around Uplift’s side and bait it into making a mistake. This backfired when I left Boom Zoom’s backside exposed for a second too long. Uplift managed to catch my exposed link, breaking the wire and removing it from the robot.

All was not lost though! I could still enter the Bounty Hunter tournament for a shot at fighting Saw Loser. With basically no repairs to do except dig the spare link out of my toolbox I jumped right in, and after frauding my way through 2 fights made it to the final against Speeny. Ironically all of my anti-drum forks had already been mangled at this point, and my longer forks were also all trashed. I had no choice but to use my short forks, which Speeny got under every time. Eventually Speeny got me upside down, grinded against my lid for a while, then once again pulled out my exposed link.

4 cheap losses from 2 very obvious problems there, that was painful. There was a lot I wanted to do to the robot before I was happy competing with it again, which I’ll be diving into when I write up the next iteration of this robot: Boom Zoom MK3.5! See you then

[James_Draper]

Really great watching the gradual progression! You did well taking so many pictures.
I love how you have retained the look and feel of the robot despite completely redesigning almost anything.

[James_Draper]

looking forward to the next installment

[ForkliftCertified (Rob Weston)]

Back at you again with that Boomy content, hot and fresh

Boom Zoom MK 3.5

With 2 events under the belt of Boom Zoom MK3, I was feeling a little down on the robot. I felt the robot was 90% of the way towards being pretty good, but that 10% was really starting to show, especially at Burgh. At least I had some clear areas to focus on when looking at improving it! These were:

1. Find a way to self-right when upside down with the lifter open
2. Find a way to stop getting link sniped
3. Rework the fork setup to be more durable and able to get under opponents better
4. Find a way to stop the 22mm motors from separating from their gearboxes
5. Make the weapon more powerful

The solution to my first problem turned out to be pretty simple, all I needed to do was add some more hairbands into the retraction mechanism and hey presto, it can self right! I wish I’d tried this at the event, but hindsight is 20/20. It’s worth noting that the longer the forks Boom Zoom runs, the more hairbands are needed to self-right it. I found 3 hairbands twisted around a couple of times to add tension was more than enough for MK3.5 anyway.

For the second issue, a little more work was needed. All previous versions of Boom Zoom had the link hanging out the back of the robot, but it was clear after having it sniped twice in a day this was way too exposed. I instead mounted it to one of the side bulkheads, and cut a hole in the lid to access it. I replaced the link mount itself with a new XT30, which I drilled an M2 hole between the 2 terminals on and mounted with an M2 bolt. This is by far the most compact and lightweight mounting method I’ve found for links, and has been absolutely bombproof since I started using it. I 3D printed a small door for the link from PLA+ and mounted it with another M2 bolt. I mounted the XT30 at a height where it would slightly poke out of the lid, so that the lid itself would press down into the link and prevent it from going anywhere. Props to Sam Price for walking me through his own link setup on Sweg and Shrekt, it heavily inspired what I ended up doing on my own robot <3

For the third issue, it was back to Fusion to get some new forks designed. The old ones were bending up far too easily on vertical hits, so I dropped from a 4mm to 3mm thickness and added a lot more material in the vertical plane to prevent this happening. I also made them a lot longer to give me the reach advantage, and added a small barb to the lifter forks to help me catch opponents and lift them more easily. Another KCut order later and they had arrived and were ready to mount, but this time they were name-brand Hardox 400 instead of generic wear plate or RAEX. I also modified the front TPU armour packages, and printed them out of a darker TPU (Overture 95A for those wondering) which didn’t quite print as nicely but was much closer to matching the colour of the RG1000 the rest of the chassis was made out of.

For the fourth issue, Sam Price once again came in clutch. He advised using hot glue-lined heat shrink to encase the motor, giving it more support to hopefully prevent the motor backing off the gearbox. I’d been loctiting the screws to prevent this since my first build, but had still lost 5 motors in my first year competing to this flaw. I bored out the mounting holes for the motors to around 24mm and applied the heat shrink, then shrank it into place with a heat gun. I was pretty happy with the result, and it had the added bonus of the hot glue at the end of the motor working to support the wire tabs, which can often break off on these motors if not handled carefully.

For the fifth issue, I wanted something more powerful than the basic 30KG servo I’d been running in Boom Zoom up until this point. I came across these very swish DMOND DBS65168V servos, capable of 65KG of torque when run directly off 4S. My servo up until this point had been running directly off the receiver so was stepped down to 5V by the BEC, so I was very excited to be able to get a full 16 volts into the weapon and get it lifting much faster and with more power than before. Sadly these servos are no longer produced, but they’ve been absolutely bombproof in my setup as of the time of writing. Your own mileage may vary, as the servo in my robot is very protected by the indirect lifter linkage compared to a lot of other applications people use servos for. It was only about 20g heavier than the old servo, and fit the exact same mounting bracket and servo horn, yippee!

I also decided to stop running magnets on Boom Zoom. It was driving very differently in the arena to how it was on my kitchen floor at home, and I didn’t have room for a giant steel sheet to practice on in my flat. Between that, the extra work they were to replace if broken, and the weight they took up, I decided a move away from them would be for the best.

With all these changes in place I was certain I had finally created an unbeatable robot (not really) and all I needed was somewhere to run it! It was at this point I went to my first RoboDojo event. RoboDojo is much closer to me than pretty much any other event (less than an hour’s drive!) and you’re guaranteed at least 4 fights per robot you bring. You’re also able to bring up to 3 antweights and 3 beetleweights per event, making it hands down the best value of any event I’ve ever done. They also run an ant/beetle event every 2 months, making it a great place to really quickly dial in any new robots or improve on existing designs. I brought 3 of my ants and Boom Zoom along to the February 2023 event, hoping the upgrades worked as expected!

RoboDojo February 2023

Boom Zoom vs ???

Boom Zoom vs ???

Boom Zoom vs ???

Boom Zoom vs ???

My first and last fights were against Colin’s big wheeled pushers, Screaming Banshee and Little Grey Fergie. I was able to get under, push and lift these very well, but Colin’s big wheels allowed his robots to free themselves from nearly every situation. I did eventually manage to pit Screaming Banshee, but Little Grey Fergie took the fight to the judges who awarded me the win!

My other fights were against the compact black vert Disaster Area, who nibbled on my forks for a while and scored some decent hits before I was able to overturn and pit him, and Nightcall, who landed some monster hits to my front before I lifted his spinner directly into my lifter, nearly cutting all the way through to my internals. The lid was still usable after this, but the front armour was absolutely mulched by the giant vert of Nightcall. It had done its job of protecting the rest of the robot though, and I quickly switched it out for a spare set between fights.

This left me on 4 wins out of 4, but Judge’s Decisions are only worth 3 points instead of 4, so I had to settle for 4th place out of 26 behind the 3 robots who’d each scored 4 knockouts. I was still over the moon to reach my first top 4 finish, and every change I’d made between Burgh and this event seemed to make the robot better! The lifter had a lot more yeet to it, the motors survived some giant impacts, the link wasn’t sniped, and I got under all my opponents! The importance of practicing driving the same robot also can’t be ignored. If you scroll up a bit and watch my pinball run, then my Dojo fights, you’ll see how much more used to driving this robot I am, which can only help!

After this event there wasn’t a huge amount I wanted to change. I finally had a chance to get a proper wedge and anti-drum setup done, and here’s what I ended up with:

I dubbed this my “Jungle Man’’ setup after its resemblance to the ant of the same name. This 2-piece TPU wedge setup doesn’t actually scrape the ground but sits with 1-2mm clearance to prevent it getting caught on any floor seams. I used eSun green 95A TPU for this, as it seemed to print stronger than the Overture filament I had which is paramount for a horizontal wedge.

For this I went back to the drawing board on my original attempt at anti-drum forks, but kept the same principle of making the radius of the fork bigger than that of the typical drum/beater they were designed to face. I got rid of the upper hook as I felt it would be easy for drums to catch that rather than grinding against the front face of the fork. I once again got these from KCut, but this time they were 8mm Hardox 500, making them even harder than my regular forks. For both this and the wedge setup I opted to replace the lifter forks with a small TPU shovel to protect the lifter from hard impacts.

I also don’t think I’ve ever shown a picture of the internals all wired up and in place, so here’s what that looks like:

With that it was time for another Dojo, here’s how it went:

RoboDojo April 2023

Robodojo Beetleweight Round 6

Fights are at 12:56, 20:28, 29:58, 36:34 and 44:32

My draw this time was a lot tougher than my last Dojo outing: Kreigmesser, Zephyrus, Gaelic Gladiator and Nightcall once again. I did still manage 4 out of 4 wins, this time all by knockout! The drum forks worked great against the Fingertech Beater Bar of Gaelic Gladiator, and the rest of the changes held up well against all my opponents really. The forks were taking damage but were always easy to bend back into shape or file back into sharp points. I got stuck under the free-standing wall in the 1st place playoff to come 3rd overall, which was still my highest ever placing at a beetle event at the time

With Robot Rebellion 2023 on the horizon, there weren’t a huge amount of changes I wanted to make to the robot. All I really did was cook up some new top armour, and some low-profile front armour packages for fighting top attack robots and non-spinners respectively. The idea with the low profile fronts is to keep the wheels exposed and leave as few catch points for the opponent to pin me as possible.

A fresh coat of paint later and we were ready to go again. Thanks to winning its heat last year, Boom Zoom got an automatic invite back as the #12 seed!

Robot Rebellion 2023

Boom Zoom - All Fights From Robot Rebellion 2023

For this event we actually knew our heat opponents ahead of time: Dolos, Data Breach and Digestive, the 3 Ds. With this in mind I was pretty happy to have cooked up a hammersaw and control bot setup ahead of time as this covered 2 of my 3 opponents in this heat.

Against Dolos, the hammersaw setup held up well. Dolos was unable to get through the top armour, and I was able to wiggle free of most of the pins he landed, but he landed a solid shot on the underside of the lifting arm, snapping one of the struts at the elbow. One of my wheels did eventually come off on its own, the set screw had managed to work loose over time and was too rounded out for me to tighten. Going down to 3 wheels barely affected the robot’s mobility however and I was able to eke out a judge’s decision for the win! I swapped out the arm for a spare I had, and replaced the rounded out wheel hub ahead of my next fight. The control bot setup also worked well against Data Breach, he had no catch points to pin me with and eventually got stuck in the arena wall and counted out. With Digestive it was basically the same strat as every other vert I’ve fought, stick the forked spinner armour on and flip it over till it stops moving, which worked a treat!

With that I’d won the heat and moved on to fight Wheely Big Lad, a Starchild-inspired kinetic thwacker. I set up by adding the top armour and low profile fronts, without any forks except the lifter forks. My strategy was to keep to the side of the lad, keep my lifter raised in the air and spear the forks through the wheel spokes. This worked well until the lad got a solid hit on the wheelguard, exploding it and wrapping it around its weapon. At this point an unstick was called and the wheelguard remains were removed from the weapon of the lad. The fight resumed, and in my haste to get the fight over and done with I pushed the lad over the pit, but its big wheels saved it and I ended up in the pit first. Oops.

Now I was out of the competition it was time to whiteboard! I replaced the exploded wheelguard and was ready to go again, and in I went with Bby Shrekt. Again it was time for the standard vert setup, but Shrekt is no standard vert. It’s one of the best of an already very effective type of robot, and is rightly feared across the scene. My approach was to avoid the forks and try to attack the parts of Shrekt’s front that aren’t protected by forks or its own weapon. I had mixed results pulling this off, Shrekt managed to catch a fork early on and completely pull both the fork and the bottom part of the lifter strut off, but I bounced back and landed a good pin in return. Eventually Shrekt’s weapon died of its own accord, but I couldn’t capitalize with a lift due to the half-eaten lifter. The rest of the fight was a pretty even pushing match, but the judges ended up giving me the win!

In the aftermath of this event I decided it was time to retire this chassis of Boom Zoom. Both of the lifters had been broken, the chassis as a whole was looking pretty sad, and I was ready to try CNCing my own with a few tweaks. I was really happy with how MK3 had done, and in my opinion this version of the robot is what took it from “just here for a good time” to “I could actually win something with this” which is something I aspired to but never really expected from this robot. This would mark the end of MK3’s service life, join me next time for another wall of text about MK4!

[ForkliftCertified (Rob Weston)]

Boom Zoom MK 4 Build Diary

Boom Zoom MK3.5 had come and gone, and at this stage I was at a crossroads of whether to go for another total redesign, or create a more refined version of basically the same robot. Not satisfied I’d learned all I could from MK3.5 I chose the latter, and began work tweaking the existing design to address some of the small flaws I’d noticed. These were:

1. With them being rigidly mounted, only 1 lifter fork would be on the ground at any one time.

2. The rear wheels didn’t entirely clear the baseplate, meaning if an opponent wedged under they could take all of the robot’s wheels off the ground.

3. During awkward lifts the robot would tip forward, taking the wheels off the ground.

4. The wheelguards had very weak layer adhesion and impact resistance thanks to using an unsuitable filament.

5. The M3 set screws in the wheel hubs were rounding out and getting stuck/falling off the shafts with use.

With this all in mind I jumped into CAD and began work! I won’t bother with pictures here as it’s visually nearly identical to MK3.5, instead I’ll jump right into how I tackled each problem:

The first issue was pretty simple to fix, the forks were secured to the lifter via 2 bolts. By removing the top bolt the fork would pivot on the bottom bolt, but was still limited in how far it could rotate by the fork’s geometry. On the CAD I just removed the top bolt hole entirely so it wasn’t reducing the overall strength of the lifter. Now both forks could rotate a little and keep in constant contact with the floor! If only all the fixes were that easy…

Fixing the second issue involved moving the wheels back a little. 3mm backwards was enough to fully clear the baseplate, but this then made the drive motors clip into the back panel. I got around this by designing some pockets into the back panel for the motor to sit in. That wasn’t so bad either!

The third issue was solved by limiting the upward travel of the non-lifter forks, tweaking the design of the front armour to stop them rotating upward past a certain point. This allowed them to act as outriggers, giving me much more leverage when lifting and stopping the robot falling onto its face. In some test lifts the front wheels stayed on the ground the entire time YIPPEE!

The fourth issue was solved by swapping yellow filaments from E-DA 97A to Polymaker 95A, which is a fair bit softer and much more impact-resistant. My hope was that this new material would flex much more, hold together better and NOT wrap itself around any more spinners!!!

The fifth issue was still straightforward to fix but involved my least favourite job in all of combat robots: tapping. Following Jack Franklin’s advice, I drilled out the Pololu hubs from M3 to M4, then tapped the new hole and added an M4 set screw. These are much less likely to round out, get stuck or fall off and were a nice if time-consuming quality of life upgrade. Here’s a before and after example of this process:

This was also my first opportunity to CNC my own frame for Boom Zoom after picking up a used 3018 desktop router from Andy Davies. After watching some tutorials and generating some gcode using Fusion 360’s CAM suite I set the machine going and was left with a lovely pile of vaguely beetle-shaped plastic. I was able to add a little pocketing on the back panel to save some weight and make room for the motors, which went swimmingly. I 3D printed some jigs for drilling the fastener holes to make sure even the manual parts of the manufacturing process were idiot-proof.

For the fasteners themselves I swapped all stainless steel fasteners to 10.9 ones for better tensile strength, and went with torx heads on fasteners wherever possible, as these are less likely to round out than hex heads and easier to remove when bent.

Robonerd Football 2023

With all this said and done, the robot was ready to go! Once again the first outing for a new chassis would be Robonerd, this time for the football! My printer quickly squirted out a custom setup for mine and Sion’s team, Crystal Meth Palace FC!

FULL Beetleweight Football Unedited footage | RoboNerd 2023

Our matches are at 6:00 and 1:59:08.

The robot put in a performance not unlike that of Prime Vinnie Jones, and together we finished 2nd overall, denied joint first by a dodgy VAR call. Game’s gone.

RoboDojo October 2023

With the testing complete, Boom Zoom was ready for a foray into full combat, just in time for October’s Robodojo meet.

Robodojo Beetleweight Fights 14th October 2023

My fights are at 2:40, 5:32, 14:48 and 24:38.

Not a huge amount to say about this one, 4 knockouts all by getting my opponents stuck in various compromising positions was pretty sweet! The changes worked perfectly, and helped by some favorable draws and no other robot scoring 4 knockouts, Boom Zoom fought its way to its first event win! I asked around and to my knowledge this was the first time a non-spinner had won a beetle event since the pandemic! I was really chuffed, even more so at the robot taking no damage.

That being said, this event really wasn’t a good test of the changes made since MK3.5. Most of the robots I fought were either very favorable matchups, having issues of their own that made it an easier fight, or some mix of the two. I was anxious to get the robot back into the arena and see if this was just a fluke, or if this robot really was a contender now. Cut to 6 weeks later…

Battle In The ‘Burgh 3

It was once again time to make the trip up to Edinburgh, this time with basically no changes made between events which was a nice change of pace.

BITB3 - Fight Night Round 1

Apologies for the choppy video, the later fights are better. Vortex was an awkward opponent, the wide gap between its forks fit my front end perfectly, and I found it was able to win frontal exchanges every time. To make matters worse, Boom Zoom was catching the floor seams much worse than usual, particularly around the pit panel. This made driving around to the sides and capitalizing on Vortex’s gyro when turning pretty difficult, but I eventually managed the push down the pit I’d been looking for. The robot had been knocked around a fair bit but it was all cosmetic damage, and before long I was ready for fight 2!

BITB3 - Fight Night Round 2

This was a rematch from earlier in the year, and since then Mark had fitted a link door to Kriegsmesser, meaning I probably wouldn’t be winning this one the same way as last time. Frontal engagements were kind of a stalemate in this fight, but I took advantage of the vert’s gyro, got to the side, flipped it onto its weapon and got it to roof itself. The shock from this knocked the weapon motor and caused it to burn itself out against its own guard. I mistook this for a more serious fire and put down my transmitter, but quickly picked it back up when it became clear the fight was continuing! With Kriegmesser’s weapon down there wasn’t a huge amount he could do except push me, so I took my foot off the gas a bit and settled for a pushing match for the rest of the fight, which despite some near misses with the pit ended in a JD Boom Zoom win!

My third qualifying fight sadly didn’t happen, as Downward Spiral was left irreparable after an earlier fight, which meant with a 3:0 record I automatically qualified for the top 16!

BITB3 - Top16

My top 16 fights are at 8:50, 15:11, 20:00 and 23:50.

Another rematch, this time from ‘Burgh the previous year in 7th Circle. I felt a lot better about my chances this time around having fought lots of very similar robots in the year since our last fight. This started well, with Boom Zoom getting under 7th Circle most of the time, but a good counter from 7th got Boom Zoom upside down. By following up with another hit to the lifter while self-righting, 7th backdrove the lifter and stripped the servo horn, killing Boom Zoom’s weapon for the first time since its first event and leaving it upside down. Finally, insisting on making it invertible actually pays off! Driving into 7th’s spinner provided a nice self-right, then I was able to control the rest of the fight with some good pushes, and despite 7th throwing its entire weapon stack at me I was able to eke out a narrow win via the judges! The stripped servo horn meant the servo itself was mercifully spared, and a new horn had the lifter working again in no time. This marked another milestone for Boom Zoom, it was the first time it had ever won a fight in a tournament bracket!

My quarter final fight was against Baby Dead Bod, my first horizontal spinner opponent since MK2 and the defending ‘Burgh champion. I slapped the Jungle Man setup on, and got my box rush in well. After knocking BDB around the arena a while, one of its drive motors dislodged and was caught in its own spinner, forcing a tap out. The wedge held up great in this fight, better than I could have expected, and came out with a few chunks missing but largely intact. A hit to the wheelguard bent the mounting through-bolts, not quite enough to lock up a wheel but still a cause for concern. After swapping these out I was ready for my semi-final against Bby Shrekt…

With Shrekt the strategy was largely the same as last time: attack the parts of his front not covered by forks. This fight started badly, with Boomy getting caught on the same floor seam it had trouble with against Vortex and being forced into a head to head engagement with Shrekt. This snapped off one of the lifter fork mounts just like at Rapture, and broke the zip tie securing the lifter elastic meaning I had no means of retracting it. I backed into the wall to try and manually retract the lifter, but Shrekt was on me and roofed Boomy with a shot that killed a drive motor. Shrekt kept the shots coming, damaging a wheelguard and killing another drive motor. Eventually Shrekt landed another shot to the damaged wheelguard and completely ripped it off, ingesting it into the weapon and completely killing itself. I managed to keep my robot moving while Shrekt was counted out, getting me into my first major beetle tournament final. I didn’t feel good about this win, and was on the verge of tapping out while Shrekt was being counted out. It was only blind luck and a bad bit of print geometry that saved me, and I resolved to make sure that could not happen with the next version of the robot. The print had torn away around the mounting bolt holes where I’d really skimped on support material. This was a totally different filament and failure mode to what happened at Rapture, where the layer lines had separated instead. With all that said and done, I had one of the bigger repair jobs I’d ever done at an event on my hands and set to work replacing the dead drive motors and ruined lifting arm, along with fixing a number of other bent bits and backed out screws.

For the final against Grab Crab I swapped out to my control bot setup, ditching the wheelguards and going with the low profile front, intent on giving him as little on me to catch and throw as possible. I also put on fresh wheels for this, as I didn’t know when I’d next be in a final and could use every advantage I could get! Things got off to a rocky start, with Grab Crab getting under me and getting me most of the way to the roof with an incredible yeet. It kept up the pressure and kept me off balance with a series of smaller flips before I was able to turn the tide with a pin and grab, pushing him towards the pit before the Crab reversed by lifting me, and after quite a struggle dumping me down the pit. I wasn’t unhappy with this result, Grab Crab was clearly the better robot and deserved the win, I was just buzzing we’d made it an all non-spinner final, and that I’d managed my first podium place at a big tournament!

Satisfied that the changes from MK3 had made a difference and that the robot was on the right path, I still had a few changes I was considering. For now though I had a robot very much still in fighting condition, and one last event to round out the year: December Dojo!

RoboDojo December 2023

Robodojo Beetleweight fights 9th December 2023

My fights are at 0:00, 8:00, 17:26, 22:43 and 23:54

My fight against Screaming Banshee was a nice one to start the day, no damage, a good pushing match, a gentle pitting, voila. Next up was Icebreaker, and the warmup was well and truly over. Front to front Icebreaker was winning every engagement, and getting around to the sides proved impossible with how well driven a machine it is. Our forks were locking together and protecting me from harm for the most part, but my lifter was getting slowly eaten every time I tried a lift or to wiggle free. Eventually, he took out yet another 22mm drive motor, making getting to the side much more difficult. A couple of flips were a nice consolation, and I was able to hang in there for a Judge’s Decision but deservedly it went to Icebreaker. After this I had a good scrap with Hooligan, where the drum forks were once again put to the test and held up fairly well, allowing me to push it out of the arena, and my control bot setup allowed me to do the same with Toucan in my next fight. This put me in a playoff for third place, with Chucky and Baby Dead Bod. For this fight I opted for a “sword and shield” approach, with forks on one half of the bot to handle Chucky, and a Jungle Man wedge on the other for Baby Dead Bod. Despite what you can hear me say in the video, I didn’t forget to put the mounting bolt in, Baby Dead Bod managed to pull the bolt through its mount with the force of its first hit, ruining the frame rail on that side. With my wedge gone, I got a little trigger happy on the sticks and when an opportunity to pit BDB came along I went full send, pitting both myself and the spinner, snagging 4th overall.

With the frame rail ruined, I once again had a choice: cut and fit a new one, or take the opportunity to redesign the robot like I’d been tempted to after Rapture. I decided this would be a good place to leave MK4, join me next time for the most extensive redesign so far, Boom Zoom MK5! This next one might take a little longer as MK5 is still active, and I’d like to wait until the version retired before I write about it. Until then

[Hoppin (Siôn Williamson)]

Boom Zoom saved my marriage.

[ForkliftCertified (Rob Weston)]

Boom Zoom MK5 Build Diary

Long time, no post! Boom Zoom MK5 has been retired for a while now, but life has gotten in the way whenever I’ve sat down to write about it. This version was a big departure from MK3 and MK4, as the core design was starting to really show its age. The main improvements I wanted to make were:

1. Add more drive power, and make the drive solution more durable.

2. Make the lifting arm more durable and easier to manufacture.

3. Increase the reach/leverage of the lifter.

4. Find a solution to the front armour mount points breaking.

5. Make the chassis easier to manufacture.

A few days in CAD later and I had this!

I’d been inspired by the construction methods I’d seen on other robots at events. I’d helped Scott work on Attitude Adjuster during his deep run at Robot Rebellion 2023, and seeing the way that was built was nothing short of game-changing to me. A TPU unibody with HDPE top and bottom panels, with aluminium hex inserts press fit vertically into the chassis. These provide rigidity for the TPU as well as a fastening point for the top and bottom panels. All this means a chassis which is much quicker and easier to make as it can be 3D printed as a single piece with no extra assembly required (aside from screwing on the lid and baseplate) rather than spending ages cutting multiple panels, making and using 3D printed jigs for the holes that the CNC can’t make, countersinking everything and putting it all together. It’s also much easier to make spare unibodies and iterate on the design going forward, so smiles all around!

For the front mounting, I opted to simply thread 3 M4 bolts all the way through the chassis with a nylock nut on top. With the TPU chassis it should be a lot less likely to pull through than it was on MK4, and even if it does, the chassis is so easy to reproduce it’s much less of a problem.

For adding more drive power, I decided to ditch the 22mm brushed motors. They’d served me well up until this point, but cramming 4 of them into the robot took up a lot of weight and space, and they were breaking with alarming regularity even when they weren’t being directly hit. I instead went for the Repeat Max motors, a much more expensive solution, but I figured I was losing my current motors at such a rate I’d soon make that cost back in replacements I’d be saved from having to buy.

I paired these with some Repeat AM32 35A brushless ESCs as these seemed like a natural fit. These motors are a lot more powerful than their brushed predecessors, so I dropped to 2 drive motors instead of 4 in an effort to save weight and space. For transmission between the two pairs of wheels, I opted for gear drive as I hold a deep mistrust for all things belt-driven. Normally when gear driving a 4 wheel drive robot, builders will put the driven gear between the two wheels as this protects it much better, and offers a small reduction making for more torque/pushing power. This wasn’t an option for me thanks to where I put the servo powering the lifter, so I instead decided to directly drive the front wheel, and use an unpowered idler gear to transmit power between the front and rear wheel. I also 3D printed some guards for the brushless motors to prevent them from eating any wires, and used the Ranglebox Mars hubs to secure the wheels to the motor shafts.

For the gears themselves I “borrowed” the settings from another builder smarter than I, Jack Franklin. The gears were generated by Fusion 360’s GF Gear Generator and are double helical (so they transmit torque more smoothly and self-align) with a 45 degree helix angle and an MOD of 2mm. I used 6mm shoulder bolts for the axles threaded into square nuts press fit into the chassis and oilite flange bushings either side of the wheels/gears to make sure everything rotated smoothly.

With the drive and chassis reworked I moved on to the weapon. The HDPE lifters were being eaten by verts way too often for my liking, and like the chassis they were a pain to remake. I instead went for a single piece TPU lifter, with the top part of the arm braced by a 2mm Grade 5 Titanium plate to add a bit more rigidity.

Finally, I set to work on the front end of the robot. Longer forks were a necessity, as I was being outforked by nearly every opponent towards the end of MK4’s run. I also incorporated wheelguards into the front armour to protect the vulnerable rear wheels, and beefed these up so they wouldn’t be ingested by any spinners like on the previous version. I also fired out a number of alternate setups like a wedge, thick drum forks, lower profile fronts and top armour to complete the usual array of setups.

With Boom Zoom MK5 finished, all that was left to do was take it out for a spin!

RoboDojo February 2024

Robodojo Beetleweight Fights 10th Feb 2024

My fights are at 3:31, 4:57, 11:59, 14:36 and 21:31

My first fight with Chucky was a good test of the waters, I got some great lifts in, won the ground game and managed to fully pick Chucky off the ground and balance it on the lifter for max style points! You may notice I was oversteering at a few points in this fight, this was me struggling with the newly found drive power of the brushless motors, which I would turn down a little for later fights.

My next fight was against Nightcall, which I was able to win simply by flipping the big vert on its back. Sorry Lucas, no way I was letting that thing get back up when I know how destructive it can be.

My third fight was against Synthblade, a really cool crusher also by Lucas. Sadly it wasn’t in a good way by the time I got to it, and a couple of flips were enough to take it out of the fight. I’d put my top armour on just in case, but it wasn’t needed in the end.

My fourth opponent was Baby Dead Bod, in a rematch from Burgh and the previous Dojo, a great opportunity to see how well the changes would hold up. I stuck my TPU wedge on, but found Baby Dead Bod was able to chew through it remarkably quickly and get to my front wheels, where a couple of hits dislodged the wheel hubs from the motor shafts and left the whole robot immobile. Rats.

After some quick repairs I was back in for a playoff for I believe 5th place? Can’t remember. Anyway my opponents were Baby Dead Bod (Again!!) and Ice Breaker, and as the least dangerous robot in the melee I let the other two largely target each other. Baby Dead Bod took a wheel off Ice Breaker who returned the favour by knocking BDB’s link out, letting me focus on the limping Ice Breaker and eventually push both it and the corpse of Baby Dead Bod off the edge.

Overall it was an encouraging first showing for the new version but I was a little disappointed not to get more stick time out of the event, my average fight must have lasted 45 seconds tops. Despite this serious problems with the wedge were revealed. Baby Dead Bod chewed through it like it was barely there, and when it did get through the lack of a groove on the motor shaft for the hub’s grub screw to sit in meant it only had to land a couple of hits before the grub screw backed out enough to kill the drive.

My fix for this for now was to dremel a groove in the motor shaft for the grub screw to sit in, and reprint the wedge with more walls/infill (basically just chuck more TPU at the problem) but while I was confident in the motor shaft fix I still wasn’t sure if the wedge would hold. Moving swiftly on to…

RoboDojo April 2024

Robodojo Beetleweight 2023/2024 Round 6

My fights are at 0:00, 5:00, 12:22, 16:45 and 18:47

My first fight was against Shrekt Force, a scary opponent at the best of times. After some jostling we both ended up with one drive side off the edge of the arena and required an unstick. Once unstuck I was able to flip Shrekt Force over, and from there keep the pressure on until I could shepherd it into the pit. A win with barely a scratch, honestly didn’t expect that!

Next was another fight against Baby Dead body, oh joy. Really though this was a good opportunity to see whether the changes I’d made since last time would help. It ended up not mattering though, after a handful of hits I got stuck under the wall, and in freeing myself oversteered and drove myself out of the arena. From the few hits it did take, the wedge held up a little better but still took far too much damage for my liking, clearly a different solution was needed.

Fight 3 was against Nightcall, and there isn’t a lot to say here, one push and Nightcall was out. It did bend one of my forks in the process though, womp womp.

My fourth fight versus Percussive Maintenance XL was another quiet one really, PMXL’s weapon wasn’t working and it’s an awkward shape for me to flip, so it was basically a pushing match till I was able to pit it. Not a lot learned from this one.

Finally I had a playoff for second place, once again against Chucky and BDB. I didn’t run the wedge in this one as it had already been compromised, and I wanted to keep my forks to stand a better chance against Chucky’s ground game. This worked to my advantage initially as BDB’s weapon went down early and I was able to pit Chucky. After pushing BDB around for a while I got a little too eager, and overcooked one of my shoves which allowed BDB to get behind me and pit me. Oops. That got me third at the event and third in the Dojo league overall, not bad especially as Boomy had only done 4 of the 6 events where points were up for grabs!

Something else good came out of this event too, Sam had decided to retire Shrekt Force, and after discovering its 2mm bent hardox wedge fit Boomy almost perfectly he very kindly donated it! There was no time to get it on the robot though because 1 week later…

Minibeasts In The East

https://www.youtube.com/live/MY8o3BTYVvk?si=qLhuypW5GsPlLyTi

My fights are at 56:25, 3:25:48, 4:50:29, 6:06:31, 6:37:34 and 7:21:05

My first fight was meant to be against another robot that had to pull out, so David graciously lent Grabber Wobba to my opponent for what was basically a whiteboard fight as it was agreed I’d get maximum points for this no matter the outcome. This was my first time in Dave’s arena since moving to brushless drive and I was very happy with how much pace Boomy was putting out, and found I was able to chuck Wobba wherever I wanted for the majority of the fight. Keen to get some stick time in, I took the fight the whole 2 minutes and had a lot of fun in doing so!

My second fight was versus Sniper, Dylan’s very nasty horizontal and reigning Dojo league champion at the time of writing. I slapped the old TPU wedge on as I hadn’t had time to mount the new hardox one and chucked it into the arena. Turns out it didn’t matter! On my initial box rush I the impact broke Sniper’s weapon brace, totally disabling the weapon almost immediately. From there I was free to invert Sniper, grab it with the lifting arm, and pit it at my leisure. Phew!

Next up was a melee with Antithesis and Flick. Two fantastic designs I felt very lucky to share the arena with, Antithesis was able to get a good crush on Flick, and I was able to turn them both over, then drive into them to separate their cuddle. This dislodged Flick’s link, leaving just Antithesis to worry about. I was able to pen Antithesis in around the pit, and after several close shaves from both of us down it went!

Next up was the quarter finals, and a rematch with Percussive Maintenance XL. This time PMXL’s weapon was working so I swapped to my additional top armour just in case. I was very proud of my driving in this fight, managing to avoid every single blow PMXL tried to land and eventually get my first ever flip out of the arena! I think this W left me a bit too confident though, you’ll see why.

Another rematch here, this time against Chucky. Chucky’s forks had grown since last time and Dylan was winning the ground game every time we locked fronts. I was desperately searching for an angle on the side for most of this fight, and in doing so hit the accelerator a little too hard and ended up with one drive side over the pit. A bit of wiggling to try and get free wasn’t enough, and soon it was all over.

There was still the matter of the third place playoff though, against EVA-02. This was another fight where I quickly found myself on the back foot, with EVA having the longer forks meaning it won most of the engagements. It wasn’t able to do any significant damage with the hammer saw, but again I had my top armour on just in case. Sadly though, I done did the same thing again and drove down the pit trying to back into EVA to score a KO.

This was still enough to secure a 4th place finish and a magnificent trophy, easily one of my favourites so far. Not a bad showing but I felt my driving and fight management let me down here. As soon as I was on the back foot in those last 2 fights I started to panic internally, and got a little too desperate to try and reverse the situation which led to me pitting myself twice in very avoidable ways.

On the build side of things, I noticed the lifter was bending quite a bit at the elbow when attempting awkward lifts, which isn’t the end of the world when that protects the servo but also means I’m not getting the most out of the lifting arm. Work to be done there for sure. No immediate changes were really warranted after this but I did cobble together a proper mount for the Shrek Force wedge, which I’d cut down to size and attached to 2 static TPU mounting pods. This meant it was once again ready for the trip down to Chatham for…

Robot Rebellion 2024

Before we get into the fights, a confession. In packing for this event, I’d completely forgotten one of my bags. This was full of all my spare lids, baseplates, lifting arms, and worst of all, alternate setups including all my forked front ends. All I had with me was the new wedge setup bolted onto the robot. This would have spelled the end of any hopes I had of making it past the heat stage, however I had a saviour in Ari, who offered to print some emergency replacements. After talking my partner through sending me the gcode files from my home PC, Ari was able to reverse engineer these into a 3D model then re-slice for their own printer, which had a different nozzle size to my own. A couple of cheeky overnight prints later I had a set of emergency front and top armour! I’d luckily remembered my forks so I was able to slot these in as well, there was a small problem, the replacement parts were bright pink! Due to being unsliced and resliced some detail was also lost, so I had to melt them a little with a soldering iron to get them to fit properly.

Robot Rebellion 2024 - Heat K

My heat fights can be found at 3:31, 15:48 and 25:49

My first fight was against the grand fromage itself, Monterey Jack. This is a glorious build, combining a miniature chainsaw and grabber mechanism to force opponents down onto the teeth. With only one set of front armour made of soft TPU and a long day of fights ahead of me, I was pretty worried about having this fight first.

Monterey Jack got stuck pretty early on in the fight, but in the interest of putting on a better show I freed it from under the wall and kept the fight going. I was able to flip the cheese not long after that, and it didn’t seem to be capable of self-righting so I kept it in that position for a while. I was eventually able to shepherd it down the pit for the win, with mercifully little shredding done to my TPU.

Next up was Bop!, an adorable hammer with some of the best theming you’ll see. Craig had been keeping Bop hidden from prying eyes under a bag in the buildup to this one, and I soon understood why. In an effort to say heck the ground game, Craig had swapped the wheels out to giant foam monster truck tyres, and Tweedy had swapped into a Bop shirt and brought out his 150g cam lifter to act as a minibot. I loved the gamesmanship of this, and it gave an extra layer of spice to our fight, as Bop would now be able to drive off my forks, and the minibot could cause problems trying to high centre me in return.

In this one Bop was monster trucking over my entire robot on more than one occasion, and while I can’t say it was too effective as a tactic it was certainly unique! Tweedy’s minibot tried to go in for some pins but most of the time my drive was enough to sweep it out of the way, though it did get a decent pin on me at one point. I in turn had a lot of fun chucking all 150g of the minibot around, I think I nearly hit the roof with it at one point! Towards the end of the fight my drive began to lock up on one side, but Bop was having drive issues of its own. I later found out from Craig he’d totally lost left/right steering, so all he could do was go forwards and backwards and hope that the robot would go somewhere vaguely productive. This did not turn out to be the case, and before long it had gone down the pit of its own accord, I can’t really take credit for that one! After the fight I quickly fixed the drive side locking up, a shoulder bolt had over tightened and was causing the wheel to bind so I just loosened it off a bit, easy squeezy.

My final fight of the heat stage was against Snek, a very innovative robot using a 6-bar mechanism to act as both a grabber and self-righter. Thanks to the way other results in the heat had gone, I’d already guaranteed my place in the knockout rounds at this point, which meant I could relax a little going into this one.

I had a fair tussle with Snek at first, but the Irish robot was having trouble keeping its front end towards me. I got around to the sides and chucked it around a bit, nearly getting stuck on the pit in the process, before maneuvering it over to the OOTA zone. From there I couldn’t resist going for the big yeet and got it over the wall to end the day 3:0 with 3 knockouts and no significant damage!

Robot Rebellion 2024 - Semi Final B

Into the knockouts we go! My round of 16 opponent was a familiar foe, Digestive. We’d fought at the previous Robot Rebellion, but this iteration of Digestive was a lot more dialled in, fixing the wedge being too low and adding some ground scraping forks to make it a lot more mobile and deadly. Normally I’d fit the anti-vert front armour which has wheelguards and forks, but today due to forgetting those I’d have to settle for no wheelguards.

I found out early in this fight I had the reach advantage over Digestive’s forks, and tried to capitalise on this by staying squared up to him. I was able to get several good flips which left Digestive break-dancing in the corner. It soon righted though and from there I pushed it back into the OOTA wall, where a lift was enough to cause the vert to engage with the wall, sending it up and over for back to back OOTAs for the first time in my roboteering career!

Robot Rebellion 2024 - The Grand Final

My later fights can be found at 15:38, 27:03 and 31:39

My quarter final and a matchup with Grab Crab awaited. Another rematch, this time of the ‘Burgh 2023 final. I was really looking forward to seeing how the improvements would hold up against the crab, especially as Joe hadn’t changed much since our last meeting so this would give a really good idea of how far Boomy had come.

This was a really cagey fight, lots of jockeying for position, flips, grabs, pushes, pins and everything in between. We both had moments where we looked on top, and there was kind of an unspoken understanding between Joe and I that neither of us wanted the pit in this fight. The only damage to speak of from either robot after this was a drive belt of Grab Crab’s that I’d prized off using one of my forks during a particularly forceful shove, and I think that might have been what swayed a split judge’s decision in my favour! This has to be my favourite (at the time of writing) robot fight I’ve ever been a part of, such a great contest from start to finish, Joe really brought it and I’d totally have understood if the decision had gone his way. Grab Crab was a big inspiration for this version of Boom Zoom, this fight felt like a sort of benchmark to compare how the robot was progressing on from MK4 and our fight at Burgh.

I’d already made it much further than I expected, but now would come the toughest test so far: Stratus. I slapped the extra top armour on, partially for the protection it’d offer but also to look more pink and therefore less of a threat.

This fight actually started better than expected! I was able to box rush Stratus and keep it off balance initially, using its significant gyro and high centre of pass to leave it dancing on one wheel the majority of the time while I pushed it around. For about the first 30 seconds or so this was pretty successful, Stratus couldn’t land many serious hits. I even managed to grab hold of one of the stabilisers, which led to some very weird gymnastics when it hit me and launched us both end over end. Around the 30 second mark Stratus got a glancing hit that knocked me upside down, then followed up as I was trying to self right and delivered a meaty hit to the baseplate. This was enough to tear a huge gash in it and peel up the edges to the point where they took my wheels off the ground, and that was all she wrote. All I could do was wiggle the lifter frantically as I was counted out. Womp Womp.

All was not lost though, I still had to gear up for one last fight for third place. My opponent was Ari with Frenzy, the very same Ari who’d printed the emergency parts that had no doubt gotten me this far. No good deed goes unpunished! Going into this fight Boomy was still very much in a bad way. The lifter hinge had been buckled by Stratus and the baseplate was still badly bent, a couple of hits to my rear could have easily high centred me again. My strategy with this fight was to force Frenzy to do a lot of turning, and hope its considerable gyro would flip it upside down. Once upside down I knew its weapon would start hitting the floor, and at that point it could end up in the pit or the OOTA zone quite easily. I had mixed success with this, but Frenzy was still able to score hits and managed to post my robot into a gap in the arena door in one of the best trickshots I’ve ever seen. Some frantic waggling was enough to free myself, and I was able to take the fight to Frenzy. The lifter wasn’t fully opening/retracting consistently thanks to the damaged hinge, but I was still able to get a few good lifts and grabs in. Eventually I was able to open the pit and invert Frenzy, and after some frenzied (hehe) bouncing on its weapon it ended up pitting itself!

I was over the moon to come away with third, especially given my disastrous start to the weekend forgetting to pack those parts. This also made me rethink just how many spares and setups I need to bring to events, I may have been overdoing it in the past bringing at least 2 sets of most setups. I also came away from this event with a concrete improvement to make: REMEMBER ALL YOUR STUFF!!! No serious changes to make off the back of this one, but that’s skewed a little by the peculiar circumstances I was in at this event.

RoboDojo July 2024

Robodojo 2024/2025 Beetleweights Round 1

My fights are at 0:23, 8:08, 15:19, 17:49 and 21:17.

First up (for what feels like the millionth time) was Baby Dead Bod, which meant I finally had the chance to test out my new wedge setup. This was a really fun one, lots of acrobatics from both of us, and plenty of meaty hits. BDB did a number on Boomy, tearing off a rear wheel and chewing up the TPU mounts for the wedge pretty badly, but the hardox held firm and I was eventually able to bounce BDB out of the arena! The damage from this one was pretty rough. I realised I’d made a mistake when designing the wedge, as it fed horizontals right up into the nuts keeping the front armour on. This meant they got a bunch of direct hits and were very hard to remove when the time came to swap setups.

Next up was Delta V, and this was a very cagey one. Our forks were locking together perfectly for basically the entire match, with the slight advantage going to Delta V most of the time. The barbs on Delta V’s forks meant we were getting stuck together a lot, even needing an unstick at one point, and when I did get free I wasn’t able to get around to the sides of Delta V and capitalize with a lift. Props to Jake’s driving on this one, he did a great job of staying squared up, and eventually time ran out for an inevitable JD loss.

Third in line was a rematch against Sniper (most of my Dojo fights are rematches at this point) again a good opportunity to put the hardox wedge through its paces. After a solid few hits the weapon on Sniper went down, and I was able to capitalise with the pitting. My mobility in this fight was hampered by the wedge catching the ground a fair bit, this would need fixing in future for sure. For now though, we move.

Fight four was against Nightcall, in what again seems to be as certain as death and taxes when I come to Dojo. I was once again able to flip it upside down, and this time after a few pushes Nightcall drove into the wall of its own accord and punted itself out of the arena!

This just left a playoff for 2nd place with, you guessed it, Sniper. When it rains it absolutely pours. The wedge did its job again, and I was able to get Sniper out of the arena pretty quickly this time to secure silver!

Overall it was great for the wedge to get as thorough a test as it did. I was satisfied with how it held up, and I hoped a few minor changes to the mounting would be all that was required to help with mobility and serviceability. The result was pretty nice too

The wedge mounts were knackered after 3 scary horizontal fights, so I reprinted them and tried a different mounting method. 6 M5 woodscrews per side, screwing into undersized holes in the TPU. I hoped these would be harder for horizontals to catch if they rode up the wedge, and also easier to remove if they were hit. Let’s see how that went…

RoboDojo September 2024

Robodojo 2024/2025 Beetleweights Round 2

My fights are at 4:44, 9:01, 16:03 and 20:53.

The first fight was against the lovely Heratoss, a flipper based partly on Bigger Brother, partly on the pokemon Heracross, name a more iconic duo, I’ll wait. I wasn’t able to get any flips in, but plenty of pushes, and after a few of those Heratoss went down. Sorry David!

Next up was a rematch against David, this time with Grabber Wobba, and this was a much better fight than our first of the day. David pulled off an insane pit escape at one point, and we had a good pushing match before I managed the KO. Sorry David! (x2)

Fight number three was against Jay and Turbulent Juice! Juice was freshly returned from the US and looked very mean indeed. Things started to look bad very quickly, when Juice hit the underside of my lifter and snapped the zip tie keeping the lifter elastic on, meaning if I got knocked upside down with the lifter open it was game over. I was able to keep the fight alive a while longer, retracting the lifter by backing into the wall but was on the back foot throughout. Juice had me over several times before scoring the killing blow and leaving me immobilised. Props to Jay, I never really felt like I had a foothold in this fight.

Finally I’d get one last chance to test out the new wedge mounting against, you guessed it, Baby Dead Bod. This started very oddly, with the pit tyre being chopped off and left in the middle of the arena by BDB as a nice arena hazard for us to fight around. Neither of us were bothered about it being there so the fight carried on, but I soon wished it hadn’t as BDB scored a big hit to the wedge which completely tore it off at the new mount points. I tried to carry on, but before long Thomas had scored a few more hits and torn off a wheel, leaving me only partially mobile. Rather than risk further damage I took this opportunity to tap out.

This last fight was pretty devastating, the new mounting had completely failed and where BDB had hit the wedgeless side again it had ruined the mounting points, making the chassis basically a writeoff. At this point I’d run the robot for the best part of a year, and was ready to make some more fundamental improvements to the design. MK6 would be next, and perhaps something else alongside it…

[ForkliftCertified (Rob Weston)]

Boom Zoom MK6 Build Diary

In which I shed a few grams, discover the power of friendship, and finally get that elusive dub…

Boom Zoom MK5 felt like a big step in the right direction, but there were still areas for improvement. These were:

1. Upgrade the drive solution to use M3 hardware, M2 heads were stripping and shearing far too often.

2. Upgrade the lifter to make it more rigid and have more flipping power.

3. Find an edge against opponents that win the ground game against me.

4. Improve the front armour mounting.

5. Save the weight I’d need to achieve the above.

After locking in on Fusion 360 for a while my computer spat out this lil guy:

Externally it looks very similar to MK5, but under the hood it’s an entirely different machine. The Repeat Maxes have been upgraded to the MK2 version to take advantage of the M3 mounting hardware. I also designed custom 3mm lasercut aluminium mount plates as the old 1.5mm Fingertech ones would bend after a while, and countersunk the mounting holes on my pillar drill. I incorporated the motor guards into the main body of the chassis as well, to cut down on the amount of parts going into each robot.

I also swapped out the 2 single drive ESCS and BEC for a Repeat dual ESC, which combines the function of all 3 parts into a much smaller, simpler package. To round things off, changed to a 530mah LiHV battery to get a little more oomph out of the robot than a regular LiPo, and upped from a 65kg to 85kg Dmond servo for around 25% more yeet! This all fit into the robot in a much lighter, neater, simpler package, and made the inside look pretty empty!

The footprint of the robot was the same as before, which allowed me to reuse the baseplates and lids from MK5, as well as most of the geared drivetrain. I did swap to a different wheel design with thinner tyres and nylon bushings instead of the old oilite ones to save a bit more weight, but that was about it for changes to drive.

For the lifting arm, I cut back on the TPU “tongue” of the lifter and extended the forks up into the elbow of the lifter so they’d still have a place to mount. I undersized the holes in the TPU slightly so the mounting bolts would thread into them, hopefully keeping the forks in place without the need for nuts. This moving the forks back added some stiffness to the lifter, but I wanted more, so I cut another piece of 2mm Grade 5 Titanium with the angle grinder and pressed it into a cavity in the elbow of the new lifting arm.

For the front armour package, I added keying features to the inside of the armour pieces and the chassis, with the mounting bolts going through both. This would reduce the amount of strain on the fasteners, hopefully making them less likely to bend/get stuck. To further help stop them getting mangled, I shortened the bolts so they no longer protruded out the top of the robot, and instead of using nylock nuts for securing them I just undersized the holes in the TPU once again. Now the whole robot is a nylock! I also dropped 2 of the static forks as they weren’t doing much, and increased the thickness of the rest of the forks from 3mm to 4mm so they’d take a little more force before they bent.

When all was said and done, I was left with this: a very similar yet different version of Boomy, weighing in at around 1250g in most setups! I’d saved all this weight for a reason, but before I could make the most of that, it was time to take it to RoboDojo to make sure the changes I’d made weren’t too rubbish.

RoboDojo November 2024

https://youtu.be/-u8pHhi_pVk?si=JsteGlOngr5EllRx

My fights are at 0:00, 6:47, 16:34, 23:50 and 30:34.

First up was Exposure, also newly rebuilt and looking much improved. This one didn’t last long, after some initial jockeying I tried a lift, but Exposure nibbled on the lifter forks and the impact pulled the mounting bolts through the TPU. Clearly I hadn’t undersized the holes enough. This left the lifter stuck open, and not long after Exposure got around me and launched me over the barrier with a big connection! Well, that was a new way to leave the arena for me. Not a lot to fix after that, just thread the lifter fork bolts back in and cut the worst of the burring off the baseplate.

Next was Chucky, a familiar (and cute) face at Dojo. After Thomas sneezed us into action, I quickly lost a wheel after the shoulder bolt backed out of its retaining square nut due to me being a bit too conservative with the vibra-tite threadlocker. Lucky for me, Boom Zoom was still moving fine on 3 wheels, and I was able to take the fight to Chucky, getting a number of flips in. Chucky responded well and got a few of its own, and after some brinkmanship near the pit the fight went to a JD, which I just about managed to take! I was very happy to see the improved reach and flipping power of the new Boom Zoom in this one, and after popping the wheel back into place I was ready to go again!

Next up was another fight with Dylan, this time though he was using Sniper. I put the wedge on, along with some shorter forks so they were protected by the wedge halves, and off we went. Once again the wedge held up well to Sniper’s impacts, but I found Sniper was out-pushing Boomy despite having no ground game of its own thanks to the insane downforce it had due to its magnets. Eventually I was able to break its traction and dump it down the pit, but it gave me quite a scare.

Fourth was Shuv-It2, and this wasn’t a very interesting one, a bit of pushing, shoving and lifting and Shuv-It got a little too trigger happy and pitted itself. I’d have liked a better fight but was happy to take the dub.

Finally was a playoff against, you guessed it, Sniper again. This time it had a friend though, a small, Chuckyish minibot with forks designed to get under my wedge and pin me so Sniper could get clean hits off. This was quite similar to our earlier fight, with me chasing down Sniper and trying to keep the weapon from reaching top speed, while Dylan would try and get away to spin up. Eventually I was able to flip Sniper over me and onto the minibot, ripping a fork away, then force Sniper into a situation where it pitted itself.

This nabbed me third place overall, a very promising result for a robot 250g underweight!

Speaking of, what was I going to do with all that weight? Now I knew the robot was broadly on the right track, it was time to make use of that weight. I’d been looking for a solution for point 3 of my improvements to Boomy, find an edge against opponents where they win the ground game. One answer is to just make increasingly longer forks, but this quickly becomes an arms race, is very boring, and hurts your manoeuvrability past a certain point. Another option would have been to find some way of disrupting an opponent’s ground game. Wide vertically spinning weapons can do this by biting on opponents forks, but there was no way I was fitting one of those onto Boomy. A third option would be “just get around to their sides” and while I like to think I’ve gotten quite good at driving Boomy, doing that consistently against other good drivers is extremely difficult. If only there was a consistent way to attack a robot from behind, or force them to turn around…

Enter the humble minibot. Those of you who watch a lot of Battlebots or NHRL will no doubt have seen plenty of these, with NHRL even offering a substantial weight bonus for their use at one point, which was heavily abused around 2022-23ish. It was common practice to see every beetleweight at one point running something like this Repeat Minibot Kit alongside their main robot, with the sole purpose of pinning the opponent’s main bot/nullifying the opponent’s own minibot:

With how lightweight and compact modern beetleweight drive options are, I figured I could make my own version, cramming a full beetleweight drive system, along with long forks and enough magnets to give it decent traction into a 250g package. After a bit of iteration in CAD, I landed on this design:

After some umming and ahhing over drive solutions, I went with Repeat Compacts, as I figured if they are meant to propel a full sized beetle they should easily let my little pusher move another full sized beetle with enough traction. A Repeat Dualie was a no-brainer for the ESC, and a 300mah 3S LiHV LiPo topped everything off. With the FS2A receiver, power light and link it was a tight fit internally, but it served. The chassis was a 95A TPU unibody with a 2mm milled polycarbonate lid to add rigidity, and it had small countersunk magnets screwed into the underside of the unibody ahead of the wheels to prevent wheelieing/provide traction when pushing. The wheels were once again TPU with cast 40A polyurethane, bolted onto Repeat gold hubs. I appreciate this whole post is beginning to sound like a Repeat Robotics advert, but what can I say, they make good stuff! Anyway the finished article looked a little something like this:

I landed on the name Titchfork for this little guy, and luckily he weighed in at only 245 grams! Time to see if it would work…

RoboDojo January 2025

https://youtu.be/F_H583sik7I?si=qPQvnA6kzlaRwYZk

My fights are at 2:00, 18:11, 26:44 and 40:09

Andy had agreed to drive Titchfork but hadn’t arrived yet, so Martin was subbed in at short notice to take the minibot for its first spin! Our first fight was against Little Grey Fergie, a relatively gentle test for our first run out. I got some good lifts in, and Titchfork got under Fergie a few times and generally made a nuisance of itself. Before we knew it, Fergie had been shepherded down the pit, and after a brief bit of infighting cease was called! This was a really encouraging early sign for the minibot, but it would get a much tougher fight in its next bout…

Gaelic Gladiator was in a bad way coming into this fight, but it was still a solid Fingertech Eggbeater capable of holding its own against any opponent. I put the drum forks on for this and passed Titchfork over to Andy for his first go with it, and off we went. This started really well, GG struggled to spin up, and Titchfork was able to land a good first pin which let me flip GG. Not long after this, GG was able to spin up, and I encountered one of the drawbacks of running a minibot: friendly fire. I got hung up on Titchfork’s forks which allowed GG to land a solid hit to my rear. More good pins from Titch followed, and flips from Boomy, but Titch had a drive side cut out seemingly out of nowhere. From here GG really turned the tide of the fight, landing a load of solid hits for the rest of the fight before cease was called. GG to GG, it got the JD.

I found the culprit for the drive cutting out on Titch pretty easily, just a grub screw on the wheel hub that I’d forgotten to loctite and had backed out. Loctiting these quickly prevented this from recurring, it was a silly mistake I would make sure not to repeat. I was also unhappy with the thick drum fork setup. By going with these shorter forks I had very little leverage with which to flip, and GG was still able to bite them, mangle the leading edge and launch Boomy without issues. So it’s no surprise that I made the decision to ditch these forks for my normal long forked setup when my next opponent was announced: Swag Demon.

This was a short one, after some initial jockeying Sweg managed to launch Titch out of the arena, but did no damage to it! One benefit to it only weighing 250g I suppose, it can be launched like an antweight and will be fine where it lands, even if it does sometimes land outside the arena. Anyway not long after I was able to push Sweg off the drop-off, landing the W!

Our final fight was against B-ASH in its pusher configuration. Not really a lot to say about this one, got lots of good flips in, Titchy got some good pins, but B-ASH was agile enough to escape every time, and eventually we went to a JD, which I won. It felt good to largely be in control of this fight, and Andy and I worked well together for the vast majority of it, always engaging B-ASH and keeping the pressure on. It definitely felt like the minibot was giving me the edge in some fights, and this was a good example.

There wasn’t much to do between events, except get some new lids cut for Titch out of 2mm Carbon Fibre (Thanks Andy!) and move both robots over to Fingertech hex switches instead of removable links. I also had to relocate the fuse wire from the links to inside the main wire looms, which I did right next to the switches. I made the “switch” (get it) to avoid losing due to having a link fall out, which can happen even with the best link securing method in the world, and I knew I’d be kicking myself if I lost that way now that these switches were newly legal in the UK scene. I cut some new lids with a better hole for the switch, and Jack was kind enough to design up a snazzy sticker for the switch hole so I’d be powering on in style, thanks Jack!

BBB Beetle Brawl 2025

My fights are at 19:40, 47:54, 1:03:36 and 1:33:07

As usual this BBB event started with a 3-way, or perhaps 4-way if you count Titchfork too. Exposure and Don’t Stop Me Now were my opponents, so on went the standard forks-with-wheelguards config. Exposure was the obvious threat in this fight so I prioritised it early on, landing some good flips which somehow worked a wheel loose, killing one side of drive. With the most dangerous robot no longer able to chase me, I switched focus to DSMN and landed some more good flips, but around this time Titchfork completely died for seemingly no reason. There was nothing for it but to push on alone against DSMN, which eventually ended up beached on the minibot’s corpse while I got launched after getting careless with Exposure. After a pause to fish out the dead minibot the fight continued, and I soon managed to KO Exposure by flipping it onto its back. I pushed and flipped DSMN around for the rest of the fight, and took the JD win to move into the knockout bracket! As for the minibot, I believe the cut-out was caused by the receiver antenna shorting against the new carbon fibre lid. I coated the antenna in Kapton tape as a precaution, and it never happened again! Happy days

Next up was Burnout, a lovely looking flipper drawing influence from Blip and Chaos 2, and it was nice to finally get a chance to fight Jevan in beetles. My long forks gave me the edge in this one, and Andy drove the minibot really well to assist. We got caught up on each other a few times in this one, but we were still finding our feet as a duo at this point. I got Burnout stuck early in the fight, but in the interest of making a more entertaining fight of it I quickly freed him. After a while I was able to coerce Burnout over to the OOTA zone and flip it over the wall for the win! I love scoring an OOTA, and this new version with the stiffened arm and more powerful servo seemed more capable of them than ever before. This win was also a new milestone for me, I’d never made it this far at a BBB event before!

My next opponent was a familiar one. I’ve fought Icebreaker a number of times at this point, and we have a pretty even record so I knew this would be tough. I started out with a box rush, which I very rarely do against verts but wanted to try and catch Adam off guard. It also showed I was winning the ground game when we went front to front which was excellent news! Andy chipped in with more great pins but Icebreaker was able to respond with hits of its own. I think I was largely in control, but Adam only needed 1 hit to completely change a fight, and soon enough he got it. Andy had pinned Icebreaker near the OOTA zone, and seeing an opportunity to end the fight quickly I charged in to try and flip my opponent out. I was a little too eager though and ended up going straight underneath Icebreaker. Before I could correct, Icebreaker had landed a hit to my rear and completely Uno Reverse Carded the situation, sending me into the OOTA zone. Fair play, I made one mistake and that was all Adam needed!

With me out of the main comp after only 3 fights, it would have been a waste coming all that way and not getting a whiteboard in. Mine was against Don’t Stop Me Now (Again), Saw Loser and a bunch of minibots! I was very excited to finally fight Saw Loser, having been a fan of Alex’s builds ever since Firestorm. I mainly focused on Saw Loser, keen to test its self-righting ability and my own additional top armour which hadn’t seen much use recently. This was a really fun fight, Saw Loser landed a huge hit on the top of the minibot, and despite ruining the lid nothing important was damaged, a very encouraging sign! After a lot of flipping and pushing I got DSMN and myself down the pit, which was then raised so we could carry on fighting! I think this meant Saw Loser won by default, but I was just happy for a good scrap.

Not a lot of changes to make after this event really, swap out the damaged lid on Titchfork for a new one and using a soldering iron to melt some of the armour on Boomy back together, plus add some countersunk magnets on the bottom for a bit of extra traction at Dojo.

RoboDojo March 2025

https://youtu.be/XIcwvei3bu8?si=ZH0iwzgxLKlToYpz

My fights are at 7:19, 16:16, 29:39, 36:04

First up was yet another fight with Chucky, but this time I had backup! Dylan had a central fork on Chucky this time which massively helped it lift me, but I had Sion driving Titchfork. Unfortunately he quickly drove himself out, leaving me on my own. Front to front, Chucky had the advantage and was on top for most of the fight, and I was only saved by Dylan accidentally driving himself out whilst trying to pit me, only for my robot to follow a split second later. This was really a win by technicality as Dylan had pushed me out, but hit the bottom of the pit first on his way out. I wasn’t going to get away with that very often!

Box N Wheels was next, a very simple 4wd pusher. I managed a couple of flips early doors, and Sion got a very good pin by the pit, making it easy to get behind him and push Box down the pit, followed by Titchfork itself! Very good work from Sion on this one, the win was his really.

Third was a rematch with Delta V, this time not rocking any kind of ground game whatsoever and with a pretty unhappy weapon. Despite this, Jake still proved a tough nut to crack, with me accidentally posting Titchfork down a hole in the floor pretty early into the fight. From there, Delta V knocked an improperly secured fork of mine loose and landed a few good hits before I flipped it on its head. After a bit more back and forth I was able to flip it once more, making it propel itself out of the arena with its weapon. Phew, wasn’t sure I would have won that on a JD!

My final regular fight was against Zephyrus, and to be honest it wasn’t a classic. Zephyrus was struggling to move, and I was quickly able to pit it before it could land any real hits. I didn’t feel great about this one, I wanted to give Morgan a better fight but by this point I was locked in on going for the event win.

The only bot between me and that win was Reisen, a very nasty new 4wd eggbeater at only its first ever event! This was a really dicey opponent, as any decent hit could easily launch me out of the arena, to say nothing of the damage it could cause along the way. Sion drove really well here and between us we were able to flip and pin until Reisen’s wheel came loose and I got it upside down, at which point we started shepherding it towards the pit. In my eagerness to get it out I reversed into Reisen but ended up with half of my own robot over the edge of the pit, but after panickily telling Sion to push Reisen down all he was able to do was push both of us, and I went off the edge first. What a throw from me! Still, 2nd place was a good result, and this actually put me into the lead for the Dojo league with only 1 event left in the season! Speaking of…

RoboDojo May 2025

My fights are at 3:27, 11:38, 14:56, 26:09 and 33:59

Baby Dead Bod was first up, so I chucked on the wedge and let Titchfork sit this one out, as I didn’t have the weight to run both the hardox wedge and a minibot. I’d also improved the mounting for the wedge this time out, press fitting square nuts into pockets in the print rather than using nylocks as I found these were catching on the ground and hampering my mobility. The wedge was working really well, maybe too well in fact, as Dead Bod went straight over me and took off a rear wheel off on its way over! Luckily my movement wasn’t affected and I carried on ramming the wedge right into the weapon, which paid off when BDB’s drive died on one side! From there I was able to push it around but BDB was just mobile enough not to be counted out, and its weapon was able to get enough purchase on the metal wedges to almost tear them off the robot, leaving them dangling like mittens from a child’s coat sleeves. Eventually BDB’s weapon went down too, and with both bots in a pretty sorry state we went to a JD which I won!

Fair bit of damage from this one, the wedge would require a reprint of the mounts (much thicker next time) and the back wheel needed reattaching where the square nut had pulled through the print, after which it was time for fight 2!

Fatal Deviation was next, but after only a single flip I’d stripped a servo horn, leaving me stuck as a pusher. I managed to stay squared up and get some decent pushes in, pausing only to free Andy when he got stranded on the arena wall, and despite some friendly fire we were able to push FD out for the win! Straight after this the servo horn got swapped out, but I feared this might happen again given this horn had not been in the robot very long at all.

Fight 3 was a rematch with Reisen, and I was really looking forward to this. Unfortunately it wasn’t to be a good one. A loose receiver plug meant Reisen quickly lost mobility and was counted out after only a couple of nibbles. Ah well, it was better than getting binbagged I suppose.

Fight 4 was another short one vs Kriegsmesser. The servo horn stripped itself almost immediately, but after a few pushes we were able to get Krieg down the pit. This is becoming a problem…

Honestly I couldn’t be bothered fixing it on the day though, which meant I was going in weaponless versus B-Ash in our play-in for third place. This went about as well as expected, with B-Ash bullying Boomy for most of this fight, and Titchfork unable to keep up to turn the tide. I was beached on the wall at one point but Andy was able to free me, and together we took it to a very decisive JD loss for fourth place.

Overall a pretty good result but without a good performance underneath it I think, only my first fight was any good, the repeated stripping of the aluminium servo horns meant I was weaponless for pretty much the rest of the event. This would need fixing before my next outing.

One silver lining though, the day’s results meant despite coming 4th I still won the Dojo Beetle league for the year! Needless to say I was extremely chuffed at this, Dojo means a lot to me as a community, and I’ve improved so much as a roboteer and met so many cool people through competing there, it made this all the more special.

To fix the servo horn stripping, I was able to source a hardened steel servo horn which is sold as part of the SSP kit bot, and quickly designed a mount and servo arm compatible with it. If this was still stripping, I was in serious trouble!

I’ve had to split this post into 2 parts due to length, next part to follow!

[ForkliftCertified (Rob Weston)]

Battle in the ‘Burgh 5

After missing out on last year’s Battle in the ‘Burgh event I was super keen to get back up there for this one, Burgh is one of my favourite events on the UK beetle calendar and this year was no exception.

https://youtu.be/JNhl14aJnrk?si=0Qffdr_LdrUwg5Wo&t=1280

First fight was Speed Hole Express, a very nifty drill bot (well, actually a Dremel bit) with some cool pontoon forks out the front. My lid is only plastic which SHE would go right through given the chance, I just had to be careful not to let that happen. We started strong, chucking Speed Hole around and keeping it off balance until it eventually got stuck. That would have been a rubbish ending, so I gave it a couple of extra flips to get it free. This proved unwise however, as right after this it got Titchfork pinned and gave it a good dremelling, melting a big hole in the front but mercifully missing anything important. After a while longer we were able to beach Speed Hole on the pit panel and hit the release, leading to the win!

https://youtu.be/KETuNAki-hs?si=Zs9c8dYoyk1LBsgE&t=893

Next was Vortex BW, and I won’t be spending much time on this for obvious reasons. Very happy with the OOTA, but a longer fight would have been nice too.

https://youtu.be/Ib5vdHoA5g0?si=l6d3r8XjCywJ4ya-&t=604

Next up was Sabretooth, an extremely cool and deadly meltybrain, so on with the wedge and away with the minibot for this one. I was largely able to keep on top of Sabretooth, which luckily wasn’t getting up to the same speeds as it was earlier in the day thanks to wearing out its own tires. After corralling it I was able to dump it down the pit, by which point it was driving around on the rotors of the brushless motors, having worn its tyres down to absolutely nothing!

My playoff fights are at 7:11, 15:38, 19:00 and 23:00.

First up in the knockout rounds was Bby Shrekt, not the draw I wanted at all. For one, Sam and I fight each other quite often at Dojo, and I saw Shrekt as probably my favourite to win the entire tournament. He also had a score to settle from the last time we met at Burgh. This one got off to a dicey start, as I realised Shrekt’s weapon was low enough that it’d still mangle my forks even if I got under it head on. After some probing engagements Andy was able to get around the back and land a great pin, giving me the breathing room to reposition. Andy was the absolute master of this all fight long to be honest, picking just the right moments to go in and take the pressure off me when I needed it. Not long after this Shrekt was able to knock me upside down with the lifting arm open, and the hairbands had stretched to the point where they could no longer retract, leaving me totally stuck! Luck was on my side though, Sam hadn’t realised I was stuck and went in for another hit, launching me back onto my wheels and continuing the fight. Andy landed another pin here and activated the pit button, and I flipped both Titchfork and Shrekt in an attempt to OOTA Shrekt (didn’t pay off) but after some more jostling I was able to push Titchfork and Shrekt over to the pit. Titchfork couldn’t correct in time and went down, but I was also able to cut off Shrekt’s escape and send it down the pit as well! Close one!

Lots of nibbles to fix after this one, a set of chewed forks and split front armour being the main issues, but after that it was time for Ray in the round of 8!

Ray surprised me by getting right under my forks with its sharpened snoot on the first engagement, but after that I was able to get around to the sides and overturn the plucky fox. With no way of self-righting, I left Ray the wrong way up and was eventually able to shepherd it down the pit for the dub. Pip was very gracious nonetheless, and was kind enough to give me my very own Ray plushie as a trophy!

Next up was the defending ‘Burgh champion, Babrog. Eoin had been having a very stressful day up to this point, and had done so incredibly well to make it through his quadrant of the bracket that I knew I had to be on my A game if I wanted to get past him. I quickly found my ground game was winning most of the head on engagements so kept squared up and kept the pressure on, but one grab from Babrog and I knew it could OOTA me. Eoin did get a couple of suplexes on me, but wasn’t able to hold the grab long enough to get me near the OOTA thankfully. Titchfork and I spent a lot of this fight trying to take advantage of how protected Babrog’s wheels were, getting it pinned in the corner or stuck trying to self-right but weren’t able to land the KO. Andy kept Titchfork between Babrog and the pit button once he saw we were ahead in the eyes of the judges, so that avenue of victory was also closed to Babrog. Eoin did manage to activate the button right before cease was called, but by that point it was too late, it went to the judges in our favour!

Here it was, my second Burgh final in a row, and this time my opponent was Jumbo Shrimp, a very well driven pusher. I felt this was a good matchup as even though Shrimp was invertible and was just as effective when inverted, Ari told me before the fight they had no way to reverse their controls when upside down. When I heard this my plan became pretty simple: land as many flips as possible to force them to correct their steering/forget which stick did what on their transmitter.

I found I marginally had the advantage when we went front to front, but Ari was very good at forcing engagements at an angle and negating my longer reach. I was still able to land a couple of decent flips early doors and get Shrimp upside down. Here Andy again came in clutch and landed some good pins, but in our back and forth we accidentally triggered the pit. After some very cagey pushing (Shrimp trying to get me down the pit, me doing everything I could to put Shrimp between me and the pit) I ended up locked together with Titchfork, and when I tried to free it I instead launched Titchfork over the wall into the OOTA zone! Oops. Now it was 1v1, and while I felt I might still be ahead, killing my own minibot would not have done me any favours with the judges. I responded by nearly pushing Shrimp down the pit, which Shrimp quickly reversed, forcing me to back into the wall and spin my wheels madly to stay alive. I then backed all the way around the pit before Shrimp could cut me off, leaving me in a good spot to flip Shrimp, then before Ari could compensate for the inverted controls I was able to push it down the pit for the win!!

I’ve said it elsewhere but I’ll say it here again, it’s been a long road to winning a tournament like this, filled with Nearlys and What-Ifs, but looking back I’m so glad things panned out how they did. Winning it as part of a team with Andy made it all the more special!

Off the back of this event there was only really one change I wanted to make, find a better solution than hairbands for the lifter retract. I settled on something I already had lying around, O-Rings! These were perfect because while still very tough and flexible, they didn’t wear out with use like the hairbands did. Perfect retracts every time, even when upside down with the lifter open! This all done, I was ready for:

Scouse Showdown 4

https://youtu.be/sR6aOX18qTw?si=Nk5LG31zUeqPK-5z&t=272

My fights are at 4:35, 14:50 and 34:58.

First up was Chucky, a familiar opponent at this point. After a fast start, Chucky had me flipped over, and when I tried to self-right I found my lifter was dead. Now unable to self-right but still able to move, I pushed Chucky into the wall, managing to self-right in the process somehow! Chucky quickly turned me over again, and this time a bolt from my lid had come loose, hampering my drive while upside down. At this point Chucky turned its attention to Titchfork which was still fully mobile, and at some point in the chaos the pit descended. I managed to work my way over to it and Chucky followed, but soon found itself caught in an awkward spot which Andy capitalised on, pinning and eventually pitting Chucky all by himself! Phew!

I really should have lost this one, Chucky was absolutely bossing me without my weapon but Andy came in absolutely clutch, so good to see the minibot once again being worth the weight! I opened the bot up to see what had killed the lifter after this fight, and was gutted to find the servo gearbox had mulched itself, much more expensive to replace. I quickly swapped in an old 65kg servo as I figured these were less likely to eat themselves with less high end torque going through them, and went in for fight 2!

Next was Bulbaroar, a very scary eggbeater which had been on a bit of a tear. Bulbaroar was running zero ground game for this fight, meaning the beater would have maximum reach, and every frontal engagement was slowly but surely eating my forks. Despite this, I was able to get under Bulba more often than not and invert it, where it would inflict much violence on the floor before self-righting. I tried to take advantage of this bouncing by shepherding it towards the OOTA zone, but wasn’t able to get the right bounce to send it out. Eventually, during a scrap over the pit, I mistimed a push and Bulba was able to get behind me and knock a wheel off, inverting me in the process. Without 1 wheel, self-righting takes me a lot longer and Bulba used this time to beat up Titchfork for a bit, folding a wheelguard into one of the wheels. I eventually got back over and re-engaged, but with less mobility it wasn’t long before Bulba landed a killer shot that knocked me into the OOTA zone. Banger of a fight that, one I’m happy to lose if it means putting on that kind of show.

Damage-wise there wasn’t much to do after this, fold the wheelguard back out on Titchfork, re-attach the wheel on Boomy and swap out the forks to a fresh set for opponent 3.

Finally was a fight with Tsukikage. This one really didn’t last long, Tsukikage’s lifter wasn’t working, so when I flipped it over I decided not to push my luck and left it to be counted out.

Despite a 2:1 record my opponent’s strength of schedule meant I didn’t earn enough points to make it into the knockout bracket, so that was the end of my day! I wasn’t too upset to be honest, this was only a week after ‘Burgh and I was just happy the robots were still in one piece.

The only change to the robot between this event and the next was to take the L-shaped piece of titanium out of the lifter arm. This was in an effort to make the lifter a bit more compliant so it wouldn’t be as likely to strip a servo gearbox.

Robot Rebellion 2025

Weirdly for this event I was billed as the number one seed, what with coming third last year and the top two not returning. No pressure then….

https://youtu.be/lPxrZaaGy7M?si=ZyWFGVgRCow97rSv&t=130

My fights are at 2:10, 5:20 and 6:26.

First up was Upcycled, and there really is nothing to say on this one. Upcycled died before I could do anything sadly, so moving on to the next…

Next was Chris Griffin 2, an absolutely crazy big horizontal spinner. Sion is a good pal, and I wanted to see what would happen if Chris hit something going full tilt, so we agreed I’d let Chris get up to full speed before engaging. So it went, and the first hit was actually oddly tame. The second destabilised Chris, which threw itself around the arena like a robot possessed, barely keeping itself out of the pit which had broken earlier in the day and was stuck in the down position. In doing so however it had snapped its own weapon belt, and not long after that it was down the pit for good! That could have been nasty, I got quite lucky in this one. Not much damage, so it was onto the last heat fight,

Crossblow was a robot I’ve been a fan of since before building my first beetle, back when I was watching old event videos and getting ideas I would always root for it whenever I saw it fight. To finally get a chance to fight it all these years later was a real treat, and the new version was looking really nice. Not content with going into this 2 on 1, Oliver enlisted the help of 2 small minibots to aid in being annoying, which they were very good at. The fight started well for me, I was able to flip Crossblow numerous times, but then the lifter once again gave out. Pusher Mode engaged once again, but Crossblow was able to turn the tide, getting a few good pins and pushes in. One of these pushes took us close to the pit, and after a hairy moment some timely reversing took Crossblow down the pit, giving me the win!

That’s 4 consecutive years of Robot Rebellion events undefeated in the group stages, though probably more by luck than judgement. The screw holding my servo horn on had undone and the horn had come off, which was a mercifully easy fix with a longer screw. Next up was the knockout bracket, and my first opponent, Initial B.

Initial B had recycled the minibots from my previous fight, so it was another 3v2. I got the initial flip on Initial B (groan) but to my horror realised my lifter was not retracting. After some fiddling I was able to manually retract it by reversing at speed, and resumed the fight with a little more care for my weapon use. I got a good ram on the B, then manoeuvred it to a corner and juggled it a little until it landed in a position it couldn’t free itself from! To complete the victory, Titchfork and I pinned the minibots to prevent them from freeing their friend.

Turned out after replacing the lifter screw I hadn’t re zip-tied the O rings to the servo arm, leaving me with no retract, another easy fix which I carried out between this and the round of 16 fight.

My next opponent was Forkhead, a formidable 360 full body lifter, excellently driven and surprisingly durable. I knew I’d have my work cut out for me in this one, but I wasn’t ready for just how quick it would be! Steve scooped me up in a matter of seconds, and my bot was just the right shape to sit in the lifter forks and be unable to free itself, allowing Forkhead to suplex me into the OOTA zone.

Sometimes you just get outclassed in this sport, and this felt like one of those times. Forkhead would go on to make the top 4, and has since taken some absolutely huge scalps in the beetle scene. I have every belief it’s one good run away from an event win.

For me though it was whiteboard time, with a twist!

https://youtu.be/6bDs3x0YmDk?si=B1uzT7R5epElnUVT

Robot Rebellion had put forward a novel idea for some of their whiteboards: 3 legged bots. Basically robots would fight in pairs, but start zip-tied together. I jumped at the idea, and teamed up with Thomas and PMXL as we thought my drive speed and his omni wheels would make for a fun combination.

Our first fight was against Ice Breaker and Sniper, a nasty enough combination 1v1, but tied together they looked even more fearsome! We went with a split config, each rocking half a wedge and single fork to try and answer both of their weapons. Swinging PMXL around for the first engagement of this fight really set the tone for it. We ended up a little more hampered by the zip ties than our opponents, and spent a lot of this fight with at least one of us the wrong way up, which wasn’t helped by Sniper cutting their own zip tie, allowing them to fight independently but also getting high centred on the zip tie in the process. I lost the same wheel I’m always losing, but eventually Ice Breaker knocked me the right way up! I took the fight to Ice Breaker but forgot I was dragging PMXL behind me, and slung it into the pit dragging us both down! This was a lot of fun, the format worked surprisingly well, and the frantic, slapstick chaos of the fight meant it was one of my absolute favourites.

Not satisfied with just the one go at this, Thomas and I went in for another go! This time we zip tied Titchfork in between us and got my partner to “drive” it, even though I’m not sure the wheels ever really touched the floor for long enough for it to do anything. Our opponents were Crossblow and Flick! Who’d interestingly decided to zip tie themselves up facing different directions. This one didn’t quite work so well, with us all getting tangled in a big pile for large parts of the fight, which wasn’t helped by Crossblow dying about 20 seconds in. After a LOT of jostling and some good axe shots from PMXL we did eventually get free and hit the pit, but then managed to instantly drive down it!

Capital Punishment: Volume 1

One last run out for this version of Boom Zoom, this time in London!

https://youtu.be/tlG_jJu-iQk?si=T19lxj9vO-xPhB9c&t=761

My fights are at 12:45, 21:26, 33:15 and 52:12

EVA 01 was my first fight, a durable 4wd pusher (and once again, Josh’s minibot) and this started once again much like any other fight between Boomy and a pusher, lots of pushes, pins, a few lifts, Titchfork getting involved, before eventually their minibot got me trapped in a very good pin near the pit. Luckily EVA shredded one of its own tires, buying time for me to escape, and by keeping the pressure on we were able to force an error and back EVA down the pit.

Next up was Clump, a very compact and stylish suplexer. It got a very early grab on me, and Ioan’s excellent driving meant I was never really settled in this fight, despite having a big reach advantage. This tense back and forth went on until Clump tried to pit me with only a partial grab, which I wiggled free from resulting in his push turning into a dive down the pit instead. Phew!

Third was Corruption, and this was a doozy. In the second exchange, Corruption managed to kill Titchfork and rip a wheel off Boomy, and from then on it was basically curtains for me. I tried to fight back but with the lack of mobility and slow self righting that comes with one wheel, Corruption was able to keep me off balance and eventually knock me down the pit. Oof.

It’s been a while since I got my arse kicked that badly, and the butcher’s bill was a costly one. Corruption had gone through the back of Titchfork and crushed the rotor on the Repeat Compact, then gone to work on the front of Boom Zoom, leaving all the front armour and forks in need of replacing. I decided to retire Titch for the day, as I only had one fight left anyway.

This was against Aero, a wide and extremely sleek hammersaw by my boi Sion. Early on in this fight I found I was being outreached by his longer forks, and had a lot of difficulty in getting around to his sides thanks to Sion’s driving. I was able to avoid any particularly bad hits though, just a couple of blows to the extra TPU top armour I’d slapped on. Finally I was able to land a lift which turned into a suplex, but his spinner caught my lifter hinge on the way over, warping it and meaning I could not get the lifter on the ground any more. It was at this stage Aero lost a drive side, plus its spinner seemed unhappy, but I was unable to capitalize on this and get Sion down the pit before time expired. We both felt we’d lost this one, but the judges did eventually give the win to Aero.

And that’s all she wrote on Boom Zoom! I’ve taken it to a few whiteboards at Botfest as well since then, but there wasn’t anything I felt was worth writing about from those fights. As this build log shows, I’ve run this robot for a long time, had so many fights with it, and learned so so much from it. Boomy still works, and it may return to the arena in some form, at some point, but its combat career in its current state is over. I’d like to try some new things, and hopefully write about them soon!

Thanks for reading, I hope there was some wisdom in my extensive ramblings!

[McMullet (Sam Roberts)]

I confess I didn’t read every single fight report, but that’s a beautifully written and extremely thorough log.

The design iterations are solid gold and I’ll certainly be pondering on your builds when I’m gradually getting around to designing more beetles!