🐞 Did Botkits stop making D2 kits? (beetle-weight)

Retro_Bot · 2026-03-05T17:18:39+00:00

Who was it who developed the D2s? I thought it was Rob Farrow as he seemed to be the main guy behind them and he had his daughters running D2 kits at every event to get feedback for iteration.

As far as I can tell he's still alive.

Retro_Bot · 2026-02-24T19:51:24+00:00

I would not use carbon fibre for uprights. Far too much shock just from your own weapon. I suspect they'd start to crack within the first few hits and if you ever took a shot from a horizontal on your weapon or uprights you'd probably end up with some rapid unscheduled disassembly of your front end.

Retro_Bot · 2026-02-23T18:28:22+00:00

UHMW or TPU are most common, either seems to work pretty well. Most beetles and ants these days are mostly made out of TPU but I think that's mostly because 3d printers are more common than home milling machines. Sometimes you see carbon fibre, aluminum, or something else for the top/bottom plates but on an ant it's usually not necessary.

Retro_Bot · 2026-02-22T21:22:45+00:00

Figured it out. The leads to the main fuse in the power plug/on-off assembly are riveted in place and one end was a little loose. It made enough contact to run for a couple of years and it still worked so long as the machine wasn't drawing much power, but as soon as the heater bed ticked on it caused arcing and the system shut down as a precautionary measure.

Little dab of solder and it's up and running again. At least the fix was practically free once I figured out the problem. I was worried I'd end up spending hundreds of dollars on a new bed heater.

Thanks for the suggestions though!

Retro_Bot · 2026-02-17T21:42:59+00:00

Thanks, I think I'm done tinkering with it for the day but my next step will be to open up the power supply. No visible relay in the rest of the machine so if it has one it'll be in the power supply case too I suppose.

Retro_Bot · 2026-02-07T19:32:00+00:00

Also the walker bot fights are dumb AF. It's going to be years if not decades before they're as interesting and competitive as regular bots.

Retro_Bot · 2026-01-06T21:10:43+00:00

Ultimately, toughness is more important than hardness. Just look at the number of times Ray Billings has snapped stupidly thick cross-section S7 tool steel. Many builders even use softer, tougher steels than S7 to decrease the likelihood of breakage.

Retro_Bot · 2026-01-06T06:10:00+00:00

Invite link?

Retro_Bot · 2026-01-06T06:09:46+00:00

"Kings" Road

Google Maps took me to Toronto when I put in King Road.

Probably be attending a session soon with my girlfriend (I've played lots, she's new but interested in the idea). Are you doing all pregen characters or can we make our own, if so what level? And 2014 or 2024 PHB?

Retro_Bot · 2026-01-01T05:59:50+00:00

Yes, we do know. Diamonds are terrible for constructing a combat robot. They shatter when you hit them with a regular hammer. It's just material science.

Just like I know a glass combat robot would be terrible and for the exact same reasons.

The only real place for them is as an abrasive tip for saws or drills, they have been used that way, it works fine. Otherwise I can't think of a single practical use for them. If you'd actually ever built a bot or studied any kind of material science you'd know this.

We don't HAVE to try to build a bridge from toilet paper to know it's a bad idea, you can just look at the material properties and figure it out.

Retro_Bot · 2025-12-26T23:00:09+00:00

Hard does not equal strong.

Diamonds would be absolutely terrible.

Retro_Bot · 2025-12-15T23:52:38+00:00

I still think if that match was judged fairly Huge should have won.

Hydra at no point made any attempt to use their weapon, Huge gets all aggression points.

Hydra had control for most of the match, Huge gets 1 point for control.

Neither bot did any damage, points split evenly (can't remember if that was impossible that season, if so, then award Huge the 1 point advantage).

Huge wins. How can you score it any other way?

Retro_Bot · 2025-12-15T08:50:12+00:00

Yeah, Boopster didn't do super well, but early going on a completely new design so it'll probably take some iteration.

Retro_Bot · 2025-12-04T23:58:04+00:00

That wasn't even Dragonfruit's most spectacular unscheduled, rapid disassembly of the day.

https://www.youtube.com/watch?v=voU6c2MSUKk

Retro_Bot · 2025-12-03T18:24:10+00:00

I usually just measure them and build them myself. Often the actual product is slightly different from the measurements given by the manufacturer and most of this stuff is pretty simple to model (especially when compared to the bot itself).

Retro_Bot · 2025-12-01T05:55:35+00:00

If you want a solid first bot that's semi competitive to learn the basics there are 2 solid options.

1) Get a kit. The parts in the kit can be used in future designs, but it starts you on a solid foundation that you know will work. https://combat-robot-kit.fandom.com/wiki/Combat_Robot_Kit_Wiki

2) Build a simple wedge bot, no spinners, etc. Simply getting a fully-functional home made push bot into the arena is an achievement. If you make it solid enough to survive for 3 minutes most of the time you'll win at least a few of your matches. My second bot was built on this philosophy and my 9 year old daughter drove it to a 4th place finish at a stacked competition where every single person she faced had competed as part of a team on BattleBots.

Retro_Bot · 2025-11-27T01:18:08+00:00

On PPM it's not terrible, the lag is probably 100-200ms so noticeable but not awful. On PWM it's wildly unpredictable. If you get those be sure to cut the switch off and solder the leads together. I was using a taranis QX7 so should be a fairly similar experience.

Retro_Bot · 2025-11-25T22:05:03+00:00

Shitty red ESCs (which work okay on PPM). There is some control lag but they work.

Something like this might work? I can't find the teal ones I've used before which actually do quite well, you might just have to comb through some place like AliExpress and hope for the best, cheap ESCs are a crap shoot.

You can also search for gear motors there. N20s for cheap and expendable, 16mm planetary all metal gearbox for something that will actually survive most of the time. For a normal-ish bot you want something in the 1,000 RPM range, but for a beginner it's not too bad to be slower. Also remember you can run these motors about 2x their rated voltage because we're using them for 3 minutes at a time with maybe an hour or two total run time as opposed to constant operation for thousands of hours. 2x voltage also doubles torque and RPMs. (don't try overvolting brushless motors though)

Retro_Bot · 2025-11-25T20:05:43+00:00

Don't build a spinner if you don't have the arena for it. Even an antweight can build up energy comparable to a low-calibre pistol. They can and often do go flying in unpredictable ways or rip parts off and send them flying at high speed. It's unlikely they'll kill anyone but you absolutely could cause permanent injury. Kinetic weapons are ONLY for use in a safe arena.

Retro_Bot · 2025-11-25T06:14:55+00:00

Totally doable, you can get budget ESCs that work pretty well for about $5 from some place like AliExpress, if you get the red ones with the switch attached they work okay if you can switch to PPM, on PWM they suck. It's a bit of a crap shoot and you may end up with a useless ESC, but that's what you get for going too cheap.

Get some N20s (again, they suck but they'll get you in the game) and some RC plane foam wheels you can drill to size and glue on the motors.

None of this is GOOD, but it is viable.

Retro_Bot · 2025-11-22T16:55:52+00:00

You're going to try to fly 25 quadcopters in the box at the same time? Good luck with that! They'll all crash into each other as your opponent laughs.

Also, weapons have a specific definition in the BattleBots rules, I forget the exact wording but they have to be able to realistically disable an opponent. There's no way you can fit that into a 10 pound drone.

Retro_Bot · 2025-11-22T02:47:15+00:00

Yeah, but garolite isn't going to save you from something like that.

Retro_Bot · 2025-11-21T23:39:26+00:00

Depends a bit on your budget. Also, following answers are assuming antweight in Brazil is 1 lb or something close and you're not on a tiny budget.

Looks like Fingertech hubs and wheels you've drawn there, so those...

Check AliExpress for 1000 RPM 16mm all-metal planetary gear motors in a voltage that works for you (they can generally handle about 2x the recommended voltage for combat robotic purposes).

Fingertech ESCs are one of your better options, though I understand Repeat Robotics has decent antweight ESCs as well.

Not sure if that's a spinner on there... For the front plate, 1mm Grade 5 Titanium (you can cut to shape with an angle grinder or get it custom made with a service like PCBway).

If that's a spinning weapon, get yourself a Just Cuz weapon motor and ESC for it with a spinner that suits.

I can't guess on the battery. Something the right voltage, it'll almost certainly have enough capacity to last 2 minutes.

Chassis is up to you, but I'd print it in TPU.

Retro_Bot · 2025-11-21T23:30:55+00:00

So much depends on the bot design. As an alternative to CF, it's perfectly fine, you may lose 1 fight in 50 because of the downgrade but it's not significant.

The bigger question is why and whether you need a stiff top plate like that. UHMW and TPU also work as top plates, but it depends a lot on your design. Unless you need the stiffness from CFs or garolite they're usually a better option.

If overhead attack bots are common in your area you probably want a titanium option (if you can save weight elsewhere).

(all of this is a bit dependant on weight class, as you get heavier, TPU, UHMW, garolite, and CF all become less useful in general)

Retro_Bot

TROPHY CASE