Team Stunt Ramp, or: How I learned to stop worrying and love the Bot

Hi,

Many of you will know me as the grinning mug who builds dumb robots which don’t work particularly well. I personally would encourage that description - I grin a lot, my robots are dumb, and they rarely work as intended.

This thread probably won’t be particularly coherent, but I thought it’d be a good idea to throw together a sort of CAD showcase for bots I’ve designed, tried to design, and failed at designing (or given up on). I doubt you’ll find anything particularly remarkable in here - most of my designs are echoes of smarter people’s ideas - but I hope that by sharing my scattergun approach to beetleweight design, I might be able to inspire some nuggets of ‘what if I did XYZ…’

First Steps

Okay, so I slapped together the OG list of recommended parts from the BBB site back in 2020 - ancient history unless you’re cool and you’ve done a hobby for longer than 3 years (nerds). That led to a plank that drove - very boring except for when I showed it off to my housemates and they all humoured me with cries of ‘oh wow, nice plank’. Lesson learnt, design something good first.

So, we come to Toutatis - named after the god of the Gauls from Asterix, but also conveniently the name of a beer. The earliest CADs I have are remarkably basic, but I learnt fairly quickly (it was 2021 lockdown and there was nowt else to do), and ended up with a couple of designs:

I opted for the latter to build - a case of ‘simpler is better’ (and also the wedge was a sensible angle).
The design was inspired by bots like Sandstorm, but used a servo actuated arm to push against the wedge and lever stuff up. It kinda worked in practice but I picked the wrong speed servo, so it was super torquey but super slow. I have never, ever, ever again forgot to read specs on components before I buy them…

Toutatis competed at Summer Showdown in August of 2021. The bot won its first fight because Sam Elliott can’t drive a train without treating every hole in the floor like a tunnel to dive into. In the next fight I promptly got stuck on my face vs Inertia. Fun design, shame it didn’t work.
NEXT!!!

Dumb Motor Ideas and Bad Simpsons References

Okay, so I got home from Bristol and immediately got given two 550s by a friend. Probably because it was my birthday a couple of days before and he’d heard I was into RC stuff now. Maybe he just didn’t want the things in his life anymore. Either way, I had to do some CAD:

Gopnik! Gopnik was a very stupid idea, a tiny amount of reduction through tiny modulus nylon gears to try and drive a big titanium wedge at other robots - a sort of D2 on steroids. I don’t know if it’d work and I’ve not spent the time or money on it to find out. The generous gift of two 550 motors sits safe and sound in my big box of parts. NEXT!!!

Shortly after designing Gopnik, I cycled around the isle of wight. That’s completely irrelevant to the next bit of CAD but I’m still proud of it and I’ll be damned if I’m not gonna milk it to the best of my ability.

Shortly after cycling around the isle of wight, I got hooked on a youtube channel called ‘Dankmus’, run by a deranged individual who chose to spend his spare time remixing Simpsons quotes into fun songs rather than burning money in a furnace or building combat robots. In particular, the song ‘H A N D S O M E P E T E’ had me hooked. To me though, there was only one thing handsomer than Pete: The recently released ‘BLIP Reveal’ video from Seems Reasonable robotics. I’m sure you can see where this is going:

The influence is pretty apparent, I feel. This was the first time I was designing a bot for use with my brand new 3018 CNC router, a tool that sounds far more impressive than it actually is (it actually is a pain in the arse but, we move.)

Everything slots together nicely, all the holes are in the right place, and it’s reasonably easy to repair, and all of that is a result of the hours and hours of me cutting parts and trying to get them to fit together and them not working! This has been a theme of my builds since the very beginning!

Handsome Pete, as this little nugget of a build came to be called, did terribly from a results perspective but did very well from a motivational point of view - I almost lasted 3 minutes vs Igor and Saw Loser 2 and met a bunch of lovely people in the process, and I generally had a good time designing and building the thing. Shame it didn’t work. NEXT!!!

The Wider Side of Life

Craig Croucher, the loveable rogue, had built a new Mr Cat’s Mouse House. It had 4 wheels and they were all along the back and gosh darn if there isn’t something so appealing about having all your wheels inline. I wanted to do something like that. And Daniel Kerrison of Australia had build a tiny little 150g ant with a jaw that rotated sideways and turned stuff over and I wanted to do something like that.

So I did.

Grapple Turnover is the world’s first beetleweight robot with a horizontal (?) rotary lifter and 4 wheel inline drive, which is themed after a particularly tasty bakery item. It’s my best name yet, I will never outdo it. It did alright at BBB Brawl, losing both its fights but getting an OOTA in the first and giving Igor a good going in the 2nd. I can’t have been too down on it cause i took it to Rapture (with a few improvements:)

At Rapture it did even better, going 2-2 in its pool and actually getting a grapple-turnover against Voltageist. Didn’t win the subsequent 3 way draw, losing to Sam Elliott (he having learnt that, in the absence of a train, a drum was more his style), but nonetheless I was very happy with the Grapple. He’ll be back one day. NEXT!!!

Stuff I didn’t Make

I designed a grab-lifter:

And another grab-lifter:

I’m waiting on the lucky third Grab-Lift design that makes it.

Okay so, that’s basically a year of robot design and it’s late and my Fusion client keeps crashing when I try to open old bots so, I’ll update this later with 2022-23. Hope you enjoy, or that it’s at least interesting. If it’s not, I don’t know what to tell you. You could be anywhere else on the internet.

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wide boys unite <3
great to see such a comprehensive rundown! v cool, those grab/lifts look tasty too

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All your bots are very cool Strang. But Grapple will forever have my heart (sorry Bonbonbonbon).

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Big love to Gopnik for sure. I really like that concept!

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hi all,

An update is on the way (including this year’s spicy CADs), but in the meantime, please rest assured that the 550s are back on the menu:

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Ooh a new episode of Strang-er things

What’s powering the waggly grabbing stick?

Have you considered high turn 540’s over 550s. When I was considering BIG BRUSHED NONSENSE I was leaning towards this as not only do you gain a little space as they’re physically shorter big they bring the RPM down and the torque up. I had a 55t spare from an RC crawler which was about 2/3rds the RPM of a silver can probably half a 550.

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Grabbing stick is powered by a 2822 1200kv overlander outrunner motor on a 1:100 28mm planetary gearbox - I could probably drop that to a 24mm gearbox tbh for the weight savings.

I’ve been considering high turn 540s - at the moment all the head-maths I’ve been doing with the 550s is 35T motors giving something like 1500-2000 RPM at the wheel on a 5:1 reduction from the motor using RC pinions and spur gears. Going to a 55T 540 would probably be a good move, more for the weight than for the space as I’m pushing up against 1200g without any frame rails (not planning on having much of a chassis for this one mind, more Gear Down For What style than anything else).

TWENTY TWENTY MOOOOOOO

It’s Cow Tools time.

Grapple Turnover is probably my favourite bot that I’ve made, but it’s an awkward bot to fix, it’s awkward to drive (it likes to flip over if you give it full welly), and the weapon… needs improvements?

After Brawl 2022 I was a bit sick of building robots out of panels with butt joints - it’s heavy, it needs lots of screws, and especially for awkward (non-box) shaped robots it’s a lot of cutting parts and drilling holes. Billets were calling to me from the cool-kids club of insectweight robotics

Add to this some weapon discs I’d bought 2nd hand, and the influence of the US 1lber Thagomizer, and you have Cow Tools - a bot designed around a 20mm billet chassis with 8mm top and bottom panels, pocketed out for components:

The bot was meant to compete at the Leicester event before Rapture, but due to the cancellation I ended up building it between Rapture and Subterranean Showdown. It’s probably the quickest a build of mine has come together, and it came out veeeeeeery light. Turns out when you’re trying a new build technique and you get obsessed with how small you can make a robot, it’ll come out about 500g underweight. Oops.

MINIBOT TIIIIIIIME

Mini Milk was thus born, designed in about 3 hours and built in about 4. It’s probably the best robot I’ve ever built:

We’re looking at 420g (puff puff) of billet chassis, 1806 conversion drive, 3mm ti forks, and magnets. If you watch any of my fights from Subterranean Showdown 2022, watch the minibot. James Jeffrey and Jack Franklin both shared driving responsibilities for the minibot that day, and did admirably. You can see a size comparison of the two bots here:

I really like Mini Milk, it’s just lovely to piss about with and is my go-to ‘you wanna drive a robot?’ bot if I have mates over. It also played a massive part in my CAD shenanigans going forward.

I also strapped a massive brushless lifter to it for RoboNerd:

It ate itself - the alu bracket holding the thing on bent under the torque, and the 2836 dug itself a big groove in the roof. Ah well.

MEGA MILK

I don’t even like milk. But I liked the minibot a lot and I wanted to scale it up and do some fun stuff with brushless gearbox setups. So I designed a full body lifter running 6S and sporting a big brushless motor on a big drill motor gearbox:

I uh, liked this one enough to do this image for it. Graphic design isn’t my passion, it’s my curse.

I wasn’t going to 2022 Champs (ended up going as a ref in the end), so this one is still on the drawing board. I might try it again some day.

A quick aside - Work in Progress

I just remembered I had another design in progress for the 550 motors I was given, but something a bit more… offensively minded than the wedge from last time:


Monch.

This evolved with the brushless boxes:

Needs longer forks ofc.
The chassis… that’s where we’re going next:

MYSTERY MEAT

This was a weird one. With the 3018 router there was an issue in terms of billet depth. I’m pretty limited to 20mm thick stock (maybe 25mm at a pinch), so taller bots aren’t particularly possible. Moreover, cool shapes are trickier. My idea was taking the 20mm billets, turning them on their side, and using stacks of them, held together by long shoulder bolts (or normal bolts), to build up a chassis. I also wanted it to be modular:



I couldn’t really decide which lifter I preferred, hence there being two.
Again, I didn’t make this in the end. Honestly I think it’s just a fear of failing to get the chassis construction working. This thing is also tiny:

Nick thought it looked like a lawnmower:

Bonbonbonbon

…will be featured next time. Sorry.

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Bonus material: Toutatis concepts, pre CAD:

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Bonus bonus material: The punching Horizontal idea that hasn’t gone anywhere but that I’d really like to build some time:

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The crusher is super interesting - I love that I am not alone in designing to use a specific part I already have then quickly versioning to something entirely different.

Bar on the overhead/horizontal/lawnmower is excellent. Reminds me of Gene Burbeck’s builds if you are familiar.

Cheers Harry! Finding a use for a component and then getting rid of the component is such a typical approach to my longer term CAD stuff!

Not come across Gene’s stuff but I’ll have to go looking.

Gene was the last word in angery insect robots in the American scene in the 00’s and early 2010s. He crammed a lot of power into small spaces and had a lot of incredible engineering and oddball brushless powerhouses.

photobucket purges killed most of his delphi posting but his flickr is still up

That Flickr is fascinating, thanks for the link - plenty of bots to root around in and find inspo for whatever ultimately comes next.

Two glasses of mega milk, please

Love the punching horizontal idea, Henry. I had a bot with a similar concept back when I did RA2 and I’ve always intended to make it a reality somehow but never gotten around to it. I ended up angling the spinner like Ironside 3 in my design, to help reduce the size of the bot, since a retracted horizontal takes up much more space than a retracted vert.

Cheers Oliver!

Really a hidden horizontal doesn’t take up much more room than a hidden vert as far as I can see - the difference is getting the punching path clear of a hit from the blade.
I’d be interested to see how you set your attempt up (even if in RA2), the ironside approach sounds very interesting!

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Sure! Yeah, I suppose it depends how you do it, but certainly in RA2 terms trying to hide a flat horizontal weapon and give it a clear path to move only resulted in massive boat like chassis!
Here’s what I ended up with. The logic was that a punching weapon would help break the fork stalemates the AI get into. I’d make some minor changes to it if I ever get around to building it irl. Things like recessing the weapon further, some more realistic forks, and moving the srimech - but the principle and overall silhouette would stay pretty similar.
I’d love to see what you do with the concept, and how it would perform - the cad looks top notch. :ok_hand:

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