Just built Hexy, now troubleshooting

Hey guys, beginner here, and I’ve just finished building Hexy and am eager to start playing around with it. However, it’s not really moving much at all. It whirls a bit, maybe one leg will move, but the others just stay still. A quick scan around the forums suggests that it might be battery problems. But it’s real late here and I’m going to leave the troubleshooting to tomorrow or something. Meantime, a quick question to help get started.

I’m thinking, should there be a specific order in which one plugs the servos in? Like, which servo of which leg should go into which numbered socket on the servo32 board? It seems like that should matter (or at least, one should remember which servo went into which socket?) This must be a real beginner question, so thanks in advance for your patience! :smiley:


Yup, sounds like low batteries.

Connection diagram is in the build guide, part 3.7:
arcbotics.com/products/hexy/star … e-hexapod/
Here’s a shortcut to the image:

Thank you roboalchemist!

Turns out the solution is to get some sleep! I plugged the servotor32 board in backwards, so all my legs were…doing strange things :laughing:

Hey guys, a couple of questions if you will!

One of the servos on hexy went out. Like the rotation does not have the slight resistance you’d get when you turn it around. It’s probably dead now and I’d have to replace it with the spare one. I’m just wondering though, if there are more robust serovs I can get, in case the others die as well? And if there are, what model and make I should be looking at?

The other question is, I’m trying to wrap my head around the inverse kinematics thing and reading up on what I can find, and it’s a bit hard going right now, but is deliciously complex hehe. This is a n00b question I’m sure, but the readings suggests that to find the position in 3D space of the knee and ankle servo, we can extrapolate all that if we know where the hip servo is using trigonometry. So…how to find the position of the hip servo though? measure it out with a ruler and such? and how does that translate to code?

I know some python, and was scrubbing through Michal’s code (the guy with the crazy dance to music routine), as well as the factory robot.py, and I’m having trouble wrapping my head around it. Any pointers will be appreciated! I mean, I’m not even sure I’m headed the right way haha!

Thanks in advance for your time guys!

We do offer metal gear servos, and as a hexy owner you can contact us for a discount code:
arcbotics.mybigcommerce.com/ … -feedback/

We did just put up a brief tutorial on how to edit PoMoCo moves, which do some of the kinematics for you, let me know if there’s more you need on it:
arcbotics.com/products/pomoco/ho … oco-moves/

Hey Roboalchemist, thanks so much for your reply and suggestions!

If I can only replace one servo from each leg, which ones would you recommend I absolutely need to switch? Hip servos seem like the ones under the most stress?

As for the PoMoCo moves editor, thanks for the link! I was actually playing with that, got hexy to patrol around my bedside, until the batteries ran out haha. However, and I’m reaching here since I’m really new to all these. I’m just thinking (I have 3D CG background and have rigged and animated characters using IK before), shouldn’t moving the body be the first part of the IK chain? The code in PoMoCo 1.0 moves the legs to move the body forward, it looks like, and that seems more like FK.

I’m really sorry, my questions must be incredibly n00b. I’m going through trigonometry now in Khan academy to refresh my memory of it, that’s how n00b I am at this, but I really want to learn, so I’m trying to do this from ground up. Really appreciate your advice so far!

Thank you so much for your patience!


Also, I have been trying to get the bluetooth module working, but it’s not. When I tried to add the device, instead of Arcbotics, the bluetooth module is identified as HC-06, and the 0000 pairing code does not work.

I’ve sort of looked around, but nothing described seems to work. my drivers are already generic drivers, and resetting the board with the bluetooth plugged in doesn’t seem to work.

Any suggestions? Could bluetooth dongler version compatibility be an issue? As in I’m using bluetooth 4.0 (it says it’s backwards compatible though, on the packaging)

It may not be backwards compatible, or it could be a bad module. If you sent us a ticket at help@arcbotics.com we can send you a new one.

I have also had this problem. It wont let me post mods and gives the same message. What do I do?