Carving problems - Losing resolution in Y Axis


Began carving today as usual, carved a legend plate, and all went well. Set up the next job, a control panel plate, and the machine went off resolution in the Y axis. I checked the belts, checked the Pulley for tighntess, and boosted the Y axis current. Tried a second attempt. same result. THEN I noticed that the motors were not locked with power on them. meaning I didn’t use to be able to move them by hand with power on them.Tried electronically locking through the control panel, no joy. Is this causing me the offsets i’m seeing? (Each pass is a little further to the right in the Y axis) IS it time for a controller repair? This unit was assembled in early May '15, so it shouldn’t be broken already?

Any thoughts? I am not going to try any more carving until I know what gives here, wasting too much material…

Keith Williams in Hoschton, Georgia

I’d look for loose stepper motor wires since you have checked the mechanical parts.

Another thought is possibly too high current limit. If the driver chip is going into thermal shutdown you wouldn’t have motor current.


Checked the wires, found one in the Axis loose, so I checked all of the other ones. Just to be sure I re-tightened them. Ran a test carve, a simple circle oval, with a depth of .050, with a depth per pass of .005. This test went well.

Re-ran my panel job. Same issue with resolution. I noticed that when I quit the job early, it did not go to the same home location. it was off about the same distance as the offset I was getting in the carve operation.

So, I reset the home position ( i cut a small dot in the acrylic so I know where home is for the job), and as I did so, I noticed that the X-axis moves a slight distance when I move the Z axis.

Anyone seen this before?

Some else had a similar problem. For them it was a single strand of wire that had slipped free of the terminal block and was shorting against the other stepper’s terminal.
So double check all the wire ends.

I’ll double check again, but I’m on the road now and wont be back until the weekend. We’ll see then…Thanks for the input and suggestions.