I've got a problem I'm struggling to diagnose.

I’ve got a problem I’m struggling to diagnose.

I’m using fusion 360, chilipeppr and tinyg. I’ve got a tool path where sometimes the x axis moves roughly +65mm mid programme (I’m pretty sure it’s happening at the same point in the program). All my zero settings then move +65mm on the x axis. Once it moved 65mm twice…

I’ve not been able to catch the exact line it’s happening on because when I go back it’s working fine.

I’m happy to attach images and screenshots but I’m not sure what i should even be looking at…any suggestions would be most welcome. Thanks, Jody

Posting a screenshot would’ve helped because then we could know what your firmware version is, whether you’re TinyG G2 or not, and whether your toolpath seems to have curves in it.

I had a similar issue when I first setup my system. However my issue was the machine would “plunge” in the zaxis. Caused a big mess. I am running the tinyG controller also. I solved the issue by setting flow control to XON/XOFF within tinyG.

So I’ve been waiting for the problem to occur again, but so far it hasn’t. I think it might have been down to a drop in the power when I turn on one of my machines. I think it’s only happened while I’ve been on another machine. I’ve noticed that the lights dim slightly when another machine is turned on. It hasn’t happened since I’ve avoided turning on the other machine while a program is running.

I’m using tinyg v8 and the toolpath did have curves in it.

Thanks for the tip Pax tech, I’ll remember that incase I have a similar issue

Earlier this year I had consistent problems with more complicated tool paths, the machine would lose position and wreck the workpiece. I ultimately root caused it to stepper drive overload/overheat. The fix was changing the 32T drive pulley to a 20T.

So, your drop in voltage would result in a rise in current. This extra current produces much more heat through I^2*R relationship.

My stepper drivers were warm but not hot when the position loss would occur, so I think the condition is a sharp transient event. The chip just cant get the heat out fast enough.

Not 100% proven theory but something to think about. You might want to separate your tinyG power source from your other loaded lines.