Hello everyone,

First off, huge thanks to Chris Annin for making the AR4 robot possible. We’ve successfully built the robot, and after overcoming several mechanical and calibration challenges, it now runs smoothly and performs as expected — until we attempt welding.

The issue we're facing is quite critical. When we start welding operations, our Teensy 4.1 controller begins to hang intermittently, and with continued welding, it eventually fails completely. After investigating, we strongly suspect the problem is caused by electromagnetic interference (EMI) induced through the limit switch wiring, which is routed along the robot’s aluminum structure.

We’ve seen other AR4 builds successfully performing welding without such failures, and we’re trying to understand what we might be doing differently — or missing entirely — in our setup. Specifically:

• Are we incorrectly routing or grounding the limit switch wires?

• Should we be isolating the Teensy completely from the frame electrically?

• Would using optocouplers, shielded cables, or ferrite beads on signal lines help?

• What protection mechanisms are commonly used in successful welding applications with AR4 builds?

  
  

We’ve documented our build in a short video which shows how the robot functions and how the wiring is currently arranged. Any guidance or suggestions from those with experience in this area would be greatly appreciated, especially from anyone who’s successfully integrated welding into their AR4 build.

I have used Chatgpt for the above to get my point across without any misunderstandings.

Thank you in advance!