Pi with 1 stepper DVR8825 and 4 DC motors and 2- L2988

[jfro]

I’ve built a ball throwing machine. 2 throw dc 12v motors. 1 dc motor for ball drop rotation, 1 motor for back and forth machine rotation, and a stepper for precise tilt of the throwing mechanism.
Early days with 3 dc motors and 2 steppers, it worked about 98% of time, but occasionally 1 of 2 stepper motors would start a small jitter (I thought it was heat).
Switched to 4 DC motors and 1 stepper and now I get jitters on the stepper. I’ve tried multiple dvr8826 drivers. Have tried separate 12v power supplies 1 for dc and pi (stepped to 5v) and 1 for the stepper driver. NO difference.

I’ve spent hours on wiring and hardware (even isolating the dvr8825 & motor outside the computer box and throw frame) and now starting to wonder if it’s in the code.

Any experience mixing stepper and high torque 12v motors?

[cbenson]

@jfro

Early days with 3 dc motors and 2 steppers, it worked about 98% of time, but occasionally 1 of 2 stepper motors would start a small jitter (I thought it was heat).

Welcome to the RobotShop Community. You’re asking for support for a a fairly complex assembly where the issue might be mechanical (as in too much torque needed), electrical or programming. Really not easy to troubleshoot.