Corruption Beetleweight Build

Coolspeedbot · 24 August 2025 22:48

On the 27th of February 2025, 5 days after BBB Brawl, an idea would form, and over the course of the following 5 and a half months, it would take form.

Introducing Corruption!

And I know what you are thinking, why hasn’t this log been made till now?

A simple reason. I wanted to keep this build relatively secret.

So let’s start from the beginning.

With a pile of old parts lying around, I placed them together to see what ideas would form. Rather quickly, the idea formed a 4-wheeled bot with small front wheels and big back wheels driven with my old 22mm brushless converted gearmotors and the drive belts from Data Breach MK1-MK2.

Old drive motors, wheel hubs and mounts all went into the build with mods/ upgrades needed.

Over the whole of March, I worked on the CAD. At first, I wanted to reuse Data Breach’s retired axe module, but I also explored a lifter design. I was happy with the drive design, but the weapons just weren’t working for me.

Near the end of March, I settled on a different direction. After years of wanting to give spinners a shot, I figured, why not now? This was an early version of the CAD. The design went through a few changes as I prototyped the design with 3D printed mockups.

While prototyping, I got the aluminium hubs modded. I chopped off the old C clip ends, and I then tapped the ends to take M5 bolts that’ll retain the wheels on the hubs.

The first tpu wheel and the weapon pulley test fitted. The pulley is fitted over a Flash Hobby D-series brushless motor. The inside of the pulley has been designed to interlock with the motor can. The bolts were simply to keep the pulley in place.

I quickly got to the point of printing the first of the TPU wrap-around armour.

The prototype chassis with electronics fitted. At this point, the weapon area was revised based on helpful feedback from Ari. I also got the 10mm diameter silver steel rod that’ll become the dead shaft for the weapon. I drilled it hollow before tapping it to take M6 bolts on either side.

In April, I realised a rather glaring issue with the design that was important to change. The back of the robot was made up of 3 sections, with the middle being a TPU part that doubled as the motor mount. Hindsight makes us fools of us all I quickly changed to a single-part back panel made from HDPE, like the rest of the chassis.

The wire loom was divided between both sides of the bot. The left side housed the FT switch, left drive motor and the battery, while the right side housed the right drive motor, main wire loom, fuse, LED and all the ESCs. The drive ESCs were two BBB brushless ESCs, and the weapon ESC was the Repeat Robotics Vortex 80A ESC. You can also see the weapon motor mounted in the middle while being supported on both ends.

The Hardox parts arrived: 6mm disks and forks with 3mm wedges for the anti-HS setup.

Test-fitted to the prototype assembly. The disks are roughly 96mm in diameter.

Learning from my mistakes from 2023, I upgraded my conversions to have a brass spacer to stop the motor can shifting.

2 of the 4 brushless gear motors ready for action. Around this time, Corruption was signed up for Capital Punishment.

Originally, I planned to have an aluminium hub for the weapon, but I was convinced to try a TPU hub with embedded spacers to save money on machining.

The whole weapon assembled weighs 360g, including bearings, spacers, M6 x 16mm bolts, TPU hub and disks. I went with M6 bolts cause I had a huge supply of them from my FW builds.

Test fitted to the bot with the newly bought belts. Originally, the weapon was going to be a 1:1 ratio, but the slightly larger hub made it 1.33333:1. In the end, the weapon would have a tip speed of 196mph.

Time to cut out the HDPE! Lots of pockets were designed to save weight, which would be needed as Corruption was pushing close to the weight limit.

To aid in the weight saving, I ground the ring gears of the gearboxes into the squares; they are not perfect, but they’ll do their job.

With parts machined and the gearboxes reassembled and regreased, it was time to start the assembly.

The 3mm base and spare were quickly made 2 days later, with some weight-saving slots added.

Originally, I wanted the weapon motor to be mounted with Aluminium mounts, but weight was too tight, 8mm HDPE to the rescue.

Weight check. Not much weight to play with and a little too close for comfort.

As always, I take what I’ve learnt from the build to set up changes for the next version. One of those changes was a lighter and smaller battery. Pulling the trigger for this build, I got 2 3s 850mah LiHv lipos, the loss of 150mah was worth the 30 grams saved. And the tasty sweet was also nice.

Side by side, the 1000mAh battery borrowed from Data breach. such a size and weight difference.

Making the last of the spares.

And with that, Corruption was ready for Capital Punishment. I’ll write up the event report in a day or two. Typing is hard.

Coolspeedbot · 25 August 2025 21:12

Before we begin the event report for Capital Punishment, we need to just add one last bit to this portion of the build log. The test videos!

I did film test driving and weapon tests a few times during the later stage of the build, however, these are the important ones. Firstly, the P.O.M. It was a rather dark, cloudy day when I filmed the POM, but as you can see, Corruption was a smooth runner, I dare say, almost handles the same as Data Breach.

And of course, a weapons test. This was filmed in an isolated area of my garden where the bot was surrounded by four walls, with me hiding behind one while doing the tests.

With those out of the way, let’s focus on the event report for Capital Punishment. Sadly, I didn’t take as many pictures as normal, so sorry for that.

Being one of the very few attending running a brand new bot, I was expecting this event to be a baptism by fire for Corruption. After a train journey into London and the underground, I arrived at the venue and was pleased that Corruption was quickly tech checked and passed with no issue.

Once the first round lineup was revealed, I only had to remove the anti-hammer-saw armour I had on for the tech check in prep for my battle with Heratoss.

At the ready table (sadly, the only time I could get both bots in a picture at the ready table)

This fight would end up being the 3rd time Heratoss’s builder, David, would battle with me at with our fights being 1:1. The bot armed up fine and drove to the starting square with ease (foreshadowing). On go, I spun up, and after a tentative start, I gave Heratoss a light hit into the air. At this point, the right-hand side of the drive stopped working, and I was forced to crab walk the rest of the fight, giving Heratoss the advantage; however, I got some lucky hits in, including the double hit that caused Heratoss’ link to full out, giving me the win.

At first, I thought it was an electrical issue with the weapon, causing the drive to brown out. I then checked the grub screws as I figured they may have loosened as I locktighted them a few weeks ago. But after that, I quickly found the issue. These old brushless conversions were showing wear as the pinion gear had worn down the shaft enough to freely spin on it. I swapped out the motor and gearbox and reassembled the bot and threw it in the test box to check the drive. Fully working again.

The second fight was with Kimmortal, which was another rematch. With Corruption now at 100% it was going to be a fun fight… till I ended it in roughly 6 seconds Kimmortal got stuck in the wall, and I tried and failed to free them, when I popped them up, the weapon caught their front panel, and it tore off, exposing their entire electronics.

A quick battery swap and I was ready for fight 3 with Boom Zoom.

Time for payback. The last time I fought Boom Zoom with Data Breach, I got stuck in the wall, and Boom Zoom left me there.

This was easily my favourite fight. With Boom Zoom being a great control bot, I expected it to be tough, especially with the mini bot thrown in too. I really gave Boom Zoom a tough fight, sending it and the mini bot into the air a few times before taking off the back wheel and killing one side of the mini bot in one strike was a real highlight. And being a real brick, Boom Zoom kept going. My tires were probably past their best by this point, and I was starting to get some loss of traction over the high spots of the arena. I still can’t believe I managed to gyro my way off the pit before it went down after getting a little stuck there. Moments later, Boom Zoom would get juggled into the pit shortly after.

After the fight, Rob was kind enough to give me some battle trophies from Boom Zoom and the mini bot.

After another battery swap and a quick retightening of the grub screws, as they were a tad loose, I was drawn against Frenzy. Time to go 3:1

This was all Frenzy’s fight. After a botched attempt to get around the back and a quick close-up to the GoPro at the start, I was stuck upside down. I had no practice with running upside down (and with possibly badly angled bunny-ears on the supports), and I was making a bad job of righting myself. Frenzy popped me on the wall before popping me into the oota zone.

The damage was rather tame for a fight with Frenzy, some slight damage to the bunny-ears and some superficial damage to one of the TPU armour sides.

I also found the bolts for the disks were starting to undo (damn threadlock), so I quickly tightened them back up, ready for the whiteboard rumble with 3 of the other 3:1 bots: Clump, Ice Breaker and bby shrekt.

This was a tad painful as I was against 3 great drivers with two of the nastiest spinners present. Corruption suffered some nasty damage, and the right-hand side of the drive died again. It was limping for survival. After a bit of time, the pit dropped, and I gyroed into it, trying to crab walk around.

Moments before the rumbles, the awards were handed out, and to my complete surprise, Corruption got one! I’m super happy with Corruption, it beat my expectations by miles.

Yesterday and today, I took a look at the damage to inspect what parts are trash and what can be kept as scuffed spares.

A cheeky shot to the base and back (almost left an event with a base plate still in the same state it arrived in )

The HDPE for a little bent into the wheel, and yet this side of the drive was flawless the whole time. After I took the bot apart, I quickly basted the bulkhead with some heat before clamping it in a vice to straighten it out, ready for use as a spare part..

The other side was a little but messed up, but a quick pass with a lighter and a craft knife, and the sharp burrs were removed, ready to join the spares pile.

The weapon uprights are toast, external damage from the rumble and internal damage as the disks worked loose again and scraped in sides of the bulkheads. The tips of the teeth of the disks had rounded out, but there is plenty of bite still left there.

Both TPU wrap-around armour panels are trashed, but they served their function.

The standoffs were a little sad and need replacing. There’s some light wear on the TPU hub, but I’ll swap to the spare just to see if the belt has worn down the groove enough to create some slack. One of the bearings was a little crunchy, but overall, the weapon worked great.

And the reason the right side went dead again? Another worn shaft and free-spinning pinion gear.

And with that, thats Corruption’s build and first event in the bag. I plan to get Corruption back up and running, ready for BBB Champs (fingers crossed). I already plan to replace my busted brushless conversions with Repeat Compacts and keep the working conversions as spares. And as I want to clean up the mess of wires, I’m swapping in the Repeat dual ESC from Data Breach. This won’t be a true MK2, more like a 1.5, as I want to get to grips with this bot more before making full-on changes.

Coolspeedbot · 4 September 2025 13:57

Almost 2 weeks later. Let’s report in on what has been done.

Here is a tweaked CAD for Corruption, featuring a changed wedge design and the addition of TPU covers for the bunny ears to help extend the life of the weapon uprights.

Goodies from the BBB store (sweets already eaten). A pair of repeat compacts, which will be a nice drop-in replacement for my conversions. I also got some of those MR30 connectors, so motor swaps are a little easier (not that I’m expecting to need to with the Repeats, but better be safe than sorry.)

The new wire loom fitted into the refreshed chassis, with all the scuffed parts swapped with the spares. (Got to look fresh at the start of an event.) New covers made to fit the Repeats, which frees up a little internal space (battery can sit flat in the bot now). The Repeat dual ESC has been wired in, and after years of using LEDs with super-thin wires, I finally replaced the wires with some 22awg wires, so no more snapping LED wires.

The first pair of bunny ear covers off the printer.

Installed on the bot, these are mostly for when Corruption fights spinners.

I’ve already filed down slots on the Repeat shafts for the grub screws to fit into. The shaft will need trimming down once the weather makes up its mind.

A quick pop on the scales, roughly 12g added from the changes. The new wedges will be roughly 10 grams lighter than the plain ones on here, so we could be roughly on par with the weight it was at, at Capital Punishment. (I am still keeping the old wedges as spares)

Coolspeedbot · 8 September 2025 23:30

Steady progress made.

The new wedges were printed; however, I didn’t notice that a small bit of geometry was left inside the slots for the captive nuts, making them useless. I fixed the error in the CAD and re-exported the files

The offending error.

After the fix

But in other news, the drive shafts were trimmed down to size.

To fit the new wedges, the front tips of the drive bulkheads were chopped down

Because I wanted to be able to use the new and old wedges, I needed to fill a small hole that would be exposed with the old wedges on. The simple solution was to trim part of the base and then heat-bend the remaining tabs to become folded walls.

The modded base fitted in place. These tabs sit flush behind the new wedges and fill the gap when the old wedges are on.

I also made a new support mount for the weapon motor out of scrap 10mm HDPE (the old 8mm one is now a spare) to help keep the bearing from popping out. I also added a small aluminium tube to the motor shaft to act as a spacer, so the bearing doesn’t shift.

Mounted in place, there is no risk of a bearing popping out again.

The new wedges (that functionally, aren’t messed up) were printed. Afterwards, I gave my printer a once-over as the wedge furthest from the camera had some tiny layer shift. I put the fresher forks on, as the ones used at Capital Punishment need some grinding. I will be putting the unused disks on for the Champs, and once I clean up the teeth on the used pair, I’ll demote them to spares. (mostly cause I want the bot to look all fresh and clean.)

Coolspeedbot · 26 September 2025 18:38

With the Champs 3 weeks away, it’s time to finish the last of the spares, check weights, and get the POM sent off.

First off were the spare weapon uprights.

I threw corruption on the scales to gauge which setup would be the heaviest. I weighed the anti-hammer saw but forgot to take off the bunny ear covers as the TPU top panels don’t fit with them on. The ear covers are 30g plus their mounting screws, so this setup is roughly 1.46kg

The standard setup, which is a perfect match for its weight at Capital Punishment. It’s impressive that the weight saved perfectly counted the weight added by the new parts.

The anti-horizontal setup is still very heavy with the addition of the ear covers. I hadn’t printed the HS wedge-compatible ear covers when I did the weight check, but I doubt there is much weight difference between the two versions. I will have to take the 3d printed belt/ motor cover off and run a 3mm HDPE panel there to save weight, just so there is a healthier margin from the weight limit.

The setup without the ear covers is roughly 8g lighter than at Capital Punishment.

With so many nuts, bolts, screws, etc, I printed new holders for them all. Now, no matter which beetle I’m running, I have everything I would need.

I took all my hardox parts and gave them a clean up before taking a nice beauty shot of Corruption.

I also filmed a new POM for Corruption, which also gave me a test drive of the new repeat compacts.

I also recast the tyres of the wheels used at Capitol Punishment. I did have to use 30A shore rubber as the 40A I normally use was out of stock. And I got all my motors wired up with connectors ready for if I need to make motor swaps at the champs (fingers crossed that doesn’t need to happen). Sorry, I didn’t take any snaps for those, but between this post and the last one, I was also hard at work on a second Beetleweight Yes, a new Beetle build log coming soon.

With car space being a little tight, I tried to take my light packing and go one level harder and plan out the packing of 2 bots for back-to-back events. Turns out it all fits into one suitcase.

So all thats left to do is print one more pair of wedges, threadlock all the bolts (closer to the event) and maybe get some stick time in. Otherwise, Corruption is ready for action.

Coolspeedbot · 6 October 2025 21:05

Welcome to Bot Weight Watchers. Lots of weight checks to know what combos weigh what.

The new cradles off the printer. The left one is Corruption, the right is for the new bot, Data-Echo. Both featuring the clips to hold onto the underside of the bots (don’t want to drop them when carrying the bot), and my little bit of swag, little tabs to hook them to my cargo pants when the bot is in the arena (no leaving my cradle on the ready table for me )

A little bit of weight saving, a simplification of the TPU covers for hammer-saws, saved 10g each

The anti-HS setup with the old wedges and the thing belt cover, weighing 1.493kg (the heaviest setup)

The anti-HS with the new wedges and the TPU belt cover, 1.4798kg (basically 1.48kg), will become the norm for the anti-HS after the champs.

In an ideal world, I’d be able to run the anti-hammer-saw tops with the anti-HS wedges, but the 3mm Hardox wedge being 71g prevents that. Need to buy some scrap/off-cuts of 2-3mm TI in the future, and I’d easily be under weight.

The forked setups are less of a headache since I opted to just drop the old wedges. The anti-hammer-saw setup is only 1.484kg.

The base forked setup. 1.4454kg

Now I know what you’re thinking, “James, why are you going to such lengths to know what combos weigh what?”

Well, one, it’s good practice (no need to do mid-event weight checks) and two, so I can hopefully find the least complex combo that weighs the most. Cause the less I have to change between the tech check and the first fight, means more time I have to settle my nerves before the first fight.

With just over a week till the event, all thats left to do is the last of the decoration and getting everything threadlocked, ready to pack.

Coolspeedbot · 14 October 2025 14:35

Days away from the Champs and the excitement (and nerves) build.

One additional task was a systems test to ensure the weapon spun up and the failsafe was functioning properly. And happily, all systems are good to go.

Afterwards, I wanted to check how well Corruption ran upside down, as that wasn’t fully tested before. The bunny ears are not perfectly supporting the weight of the weapon, so the bot wants to leap onto its front, but during this testing, I found out that a full reverse can right the bot. Those TPU covers for the weapon uprights must have helped push the centre of gravity over enough that the drive can throw it back over. We’ll have to wait and see how it fares in the arena.

Coolspeedbot · 21 October 2025 17:46

Event Report Time.

Corruption was prepped and packed with its companion Data Echo (my entry to the Loughborough event the following day). Corruption was Tech Checked with ease, and once the draw was announced, I swapped out the anti-horizontal setup for the anti-hammer-saw setup.

The reason was that the first fight was against Perpetual and Luchador; this was a scary fight as Luchador was a former champ and a good control bot, and Perpetual could drill through my armour if I gave it a chance.

Starting in front of the oota zone, my plan was to get away from that before a box rush could keep me there and potentially throw me out. After a little locking of the forks with Luchador, I was rather surprised that a pop from the spinner sent Luchador out of the arena. The rest of the fight was me getting pinned by Perpetual when I wasn’t landing hits. Granted, I was holding back, waiting to see if they were going to be counted out a lot, and wasn’t being super aggressive and kept giving Perpetual breathing room. Perpetual got one more pin in before driving me into the pit. In hindsight, I should have reversed during the pin release before driving forward, as that would have freed me from the forks.

There was no real damage to speak of, and a quick battery swap, and I was ready for the redemption round, and boy was I going to be out for blood.

The redemption fight was against Monterey Jack, who had just finished reassembling their whole bot. I was worried about that chainsaw damaging my base if I got pinned, so I had to hope I had the better ground game here.

A very fast fight, 2-3 hits and Monterey Jack was out of the arena. A quick battery swap (I always run fights with a full battery, no matter how short the last one was.)

The next fight in the round of 32 was against Stasis, a vertical spinner with more reach than me, but a more fradle fork setup.

I was careful but aggressive, aiming for the side of Stasis and taking out some of the forks while getting some good pops with my weapon, trying not to let Stasis get any breather at one point, digging my disks into the base of Stasis and narrowly missing the lipo. With another head-to-head exchange, Stasis was upside down and vulnerable, but part of my weapon belt was cut, reducing my weapon speed greatly. With Stasis stuck on its side against the OOTA zone, I had to back off for a count-down to get the win, as I had no chance of throwing them over the wall with my weakened weapon.

As you can see, my belt was looking more like a cheese string than a belt. Thankfully, a belt swap was all I needed to fix the weapon. I did a quick test in the test box and was happy to fight.

The round of 16 once again (would it be 3rd time lucky?) This was against Lilith, a front-hinged flipper. I wasn’t sure how this fight would go.

This was a quick one; I just kept attacking until a loose connection caused Lilith to stop working, and I tapped out. This meant Corruption was now in the top 8!

A little bit of red paint from Lilith. A quick Battery swap again, and I was ready for my next fight.

Whoops, no ready table picture, Cascade and Corruption were called into the arena before I could get my phone out.

The fight was off to a terrible start. Corruption was mid-gyro when the weapon hit Cascade, sending Corruption flying and landing on its face against the wall. Cascade was a really great sport and freed Corruption, so the fight could be more of a fight. With Corruption righted, we had another head-to-head engagement, and this time, Cascade was sent flying and got stuck on the wall in the same spot where Corruption was just seconds ago. It was only right to return the sporting kindness, and I freed Cascade to keep the fight going. Then it became a bit of a case of interlocking face-to-face a lot, with some small pops from my weapon. Granted, having been a control bot driver for 9 years, it was hard to get into my head that I needed to back off more to get my weapon up to speed. Then, the pit button was pressed, and the pit lowered, which was not ideal. Corruption ended up launching itself again and just missed the pit. I was just about able to self-right and get away. A little more dancing around and with the better ground game, Cascade was able to shove me in the pit, and that was it.

A good event with lots of areas of improvement from more rack on the disks, longer forks, and better driving from me.