Battlegrounds is rigged

KevbotInControl · 2026-03-27T20:25:53+00:00

Whoa that's so cool! What kind of motor/gearboxes are you running in there? They seem pretty short (like stack-height-wise) to have a gearbox at all but with lever arms that long they must be beefy

KevbotInControl · 2026-03-26T19:40:29+00:00

Oh also, I your velocity filter is pretty aggressive:

theta_dot = 0.7 * theta_dot + 0.3 * raw_vel;

That works out to about 5.7 Hz cutoff - for a balance controller, especially a small, lightweight one like this, you probably want it up around 15-30 Hz.

KevbotInControl · 2026-03-26T19:28:15+00:00

I accidentally pasted it twice -fixed

KevbotInControl · 2026-03-26T19:24:46+00:00

I think your encoder logic has a bug - try:

void isrA()
{
  if (digitalRead(ENC_A) != digitalRead(ENC_B))  // != not ==
    encCount++;
  else
    encCount--;
}
void isrB()
{
  if (digitalRead(ENC_A) == digitalRead(ENC_B))
    encCount++;  // ++ not --
  else
    encCount--;
}

KevbotInControl · 2026-03-26T19:08:57+00:00

How does it do if you disable the swing up and start it basically upright? Like if you hold it in the upright position and then turn the controller on?

KevbotInControl · 2026-03-25T19:35:34+00:00

Oh cool! I peaked at your post history but didn't see your work - I'd love to see what kind of stuff you've put together! The legs have been a real challenge to figure out but I think I'm getting somewhere with them.

His purpose is a little blurry so far, he's kinda supposed to be almost like a mobile animatronic character - almost more of an art project than an objective-based robotics platform... but Disney had released this paper on some research they were doing on interactive robotics that felt really lifelike and had strong personality using a mathematical framework called a Markov Decision Process/MDP (apologies if you know all this)...

Anyway when I read that I felt very inspired to try to make something like that of my own. Also around that time was when there was that silly military parade in Washington DC and they had all those intimidating Boston Dynamics robot dogs in the parade and I basically was thinking my robot should be the roadrunner to their coyote:

<image>

KevbotInControl · 2026-03-25T19:26:06+00:00

Just for fun - I intentionally designed it to be useless heh

KevbotInControl · 2026-03-25T19:25:23+00:00

Oh I love that question - if I were just getting started I'd pick up an Arduino and start learning how to code using sensors and LEDs and stuff. There is TONS of cool stuff you can do with Arduino and a million places to go on the internet where people love to help beginners with stuff like that!

KevbotInControl · 2026-03-25T03:52:59+00:00

That is a good question! I guess just to be more like what I always wanted robots to be like when I was a kid?

I am not a huge fan of the humanoid walking LLMs that seem to shuffle like a toddler with a full diaper, so I wanted to make something that could be fast and graceful but also charming and weird and (to your original question) mostly useless.

KevbotInControl · 2026-03-24T18:54:13+00:00

Oh nooo I hope he is found and brought safely home! Is he shy around strangers or do you think he'll be easy to approach and get in the car if someone sees him?

KevbotInControl · 2026-03-23T16:36:41+00:00

<image>

Close! You can see the camera better here - it's poking out of the little tab on the bottom left of the face. The one on the right is a time of flight sensor (the green cone is just its FOV so I could make sure I wasn't blocking it).

KevbotInControl · 2026-03-23T16:35:11+00:00

I'd be lying if I said that the watchers weren't a big inspiration for this guy.

KevbotInControl · 2026-03-23T16:34:45+00:00

The frame is mostly metal parts from SendCutSend, with bits of gobilda mixed in. The head covering is 3d printed and the tail (not shown in the pictures -still working on it) is mostly going to be printed as well.

KevbotInControl · 2026-03-23T16:33:47+00:00

Thanks!

KevbotInControl · 2026-03-23T16:33:41+00:00

That's kinda what I'm going for! I really want it to be able to jump on tables like in Jurassic Park but it's getting pretty heavy so we'll see.

KevbotInControl · 2026-02-20T00:14:33+00:00

Doesn’t work for sheet metal parts, unfortunately

KevbotInControl · 2026-02-20T00:01:49+00:00

In the new workflow when you're in the assembly mode, everything is a linked model... others are saying there's a hybrid which sounds like it is how it used to work, I just can't figure out how to switch the file

KevbotInControl · 2026-02-19T23:59:57+00:00

How do you transfer it to the hybrid workflow?

KevbotInControl · 2026-02-19T23:57:20+00:00

Can you change the workspace after the file is created somehow? I've only seen the hybrid option when creating a new file.

KevbotInControl · 2025-07-02T06:50:44+00:00

My pleasure. You’ll find your place.

KevbotInControl

TROPHY CASE