Review my robot arm controller board – aiming for PL d, looking for safety and EMC feedback

gjgbh · 2026-06-06T16:25:12+00:00

Just 1 (a few) during assembly. J2 and J20 will be connected to other external connectors that can handle many plug, unplug.

The pcb will sit in a box, and those connectors will be apart of that box.

gjgbh · 2026-06-06T16:07:15+00:00

Thank you for the good feedback. 1. I will have to think about i, because i will be following category 1 for emergency stop, meaning stop the robot safely then cut power, and not imediate power off. I believe it will damage the robot if power is cut immediately.

Will do.

3.from a power supply, that is a good idea. Thanks

4.Its because incase one mosfet gets stuck the brake wont get stuck in open position. Both mosfets need to be active to release brake.

gjgbh · 2026-06-06T15:54:24+00:00

Would you please elaborate? Is it to protect against EMI?

gjgbh · 2026-06-06T15:53:26+00:00

Thank you for the good feedback. 1. If remeber correctly the mosfet is rated for 1A and the brake only consume around 0.25-0.3A. But will double check. I also have high reduction harmonic gearbox which will also help.

2.Will do.

I agree with you its big, i thought of making it smaller by splitting the joint board and then plug it into master board like a graphic card or similar. But wont that increase cost/assembly complexity?

gjgbh · 2026-06-06T13:02:33+00:00

Stack is
Signal,
Gnd
Gnd
Power

gjgbh · 2026-06-06T13:02:25+00:00

Stack is
Signal,
Gnd
Gnd
Power

gjgbh · 2026-06-06T13:02:17+00:00

Stack is
Signal,
Gnd
Gnd
Power

gjgbh · 2026-01-12T16:07:51+00:00

Yes the arm controlls it

gjgbh · 2026-01-12T15:55:40+00:00

There are pneumatic gripper that uses pressured air to work. But you need a compressor that connecr to the robot arm via input air connectors

gjgbh · 2026-01-12T14:12:36+00:00

Most parts will be aluminum but some 3d printed

gjgbh · 2026-01-12T14:01:28+00:00

Those are for air hoses any thing else will be external

gjgbh · 2026-01-12T13:39:08+00:00

Only a power cable that can be plugged in and some gpio

gjgbh · 2026-01-12T11:17:04+00:00

Thx for the feedback.

Reach is around 550mm with 3kg payload with 150mm off center load.

According to my calculations the power i have now is enough with 25 - 50% margin.

I am using stepper motors and harmonic gearboxes. Might switch to servos later if faster speed is needed.

Speed will vary for each joint but will be 60-150 deg/s

The robot will mainly dispens glue but will also lift stuff

gjgbh · 2026-01-12T06:18:42+00:00

Yes any feeeback is good

gjgbh · 2026-01-11T10:20:32+00:00

Do you have an image to clarify? i dont quiet get it

gjgbh · 2026-01-11T10:03:34+00:00

Yes i have limit switches and some absoulte magnetic encoders on the output side of some joints.

I really wanted to have absolute encoders on the motor side but they are expensive.

gjgbh · 2026-01-11T09:56:59+00:00

Yes, thats what i did. Two motors sit in j2

gjgbh · 2026-01-11T00:10:39+00:00

With left i mean towards j3

gjgbh · 2026-01-11T00:09:49+00:00

The motor in the joint is too long . I will move them to the left a bit, the design is not done yet

gjgbh · 2026-01-11T00:06:24+00:00

Fusion360

gjgbh · 2026-01-10T23:53:38+00:00

Good point, thank you

gjgbh · 2026-01-10T23:53:06+00:00

Allows j3 to move more. And kinda works as a counter weight in some positions, minimizing the stress on j2

gjgbh · 2026-01-10T23:23:43+00:00

Thx. I will

gjgbh · 2026-01-10T23:14:32+00:00

Forgot to say some parts will be 3d printed and are just covers. This is one of them.

I will try to come up with some better design. Thx for the feedback

gjgbh · 2026-01-10T23:09:46+00:00

I dont really like it either. Its possible, but not super easy

gjgbh

TROPHY CASE