Nice find.  This would certainly bring the cost down.  Anyone know the compatible BLDC motors. His Robot design doesn’t use a drive belt like the other designs (i guess you could change this) and all wiring internal.  I do worry the continual twisting of the wires would cause them to break over time especially when you have 3 motors back to back (maybe that is why he put the 3rd motor in the middle of robot leg).

@Nink, Should be compatible with any motors in the controller's voltage range (10v-40V). Belts and gear boxes are giving you all the extra torque...you can run right off the motor (lower KV) if your robot is small enough without all the gearing. Also as long as you have a slip ring like he demoed wires should be ok...especially because his controller is set up like a servo at 1-180 degrees vs multi turn.

Edit: Also looks like he is sold out of everything....and not been any for awhile...he has posted everything open source so you can build your own board....sigh

The video shows you need a BLDC motor with a central magnetic encoder at core.  Some BLDC seem to have hall magnets on the circumference not in the center and others seem to have no magnets for hall sensors at all.

Yeah I was thinking you could just use the special magnet like the one included in the MJBots dev kit and it would work with his magnetic encoder. But with out the hole in the center, you would have to keep your wires outside the motor, which won't be a problem. I think maybe its because he is showing it with the controller rotating with the motor at calibration at 2:37...which it doesn't when installed in the leg..see the video at 6:00 mark. Now the motor is inverted and the part of the motor with the controller wires is on the bottom and not moving with the motor. He has wires going through, but you could easily have them outside of the motor with no problems getting twisted up.

Hey, I also noticed that the guy is no longer active...I guess that is also one thing that we should keep in consideration. If we are going for a cheap diy version, there is always the possibility of grinding to a dead stop when it comes to development. I would not mind to get those PCBs made somewhere, I mean you'd need a few anyways. So the price might be OK?

But if there are any issues, there is no one to give a helping hand and you'd be there by yourself...

So I guess, unless there is someone with enough knowledge popping into this adventure, it would be not the very best option!

But man, the ODrive and the Moteus will cost a lot of money if you are going to build a quad! For a 4DOF arm it is fine, but a quad will be much much more!!

Btw...I moved the encoder to get a bit more room!!

Trying a new BLDC style joint...lets see if this works!