X Axis Keeps Skipping

Hi team -

New owner of a very used X-Carve. It was pre-2021 when I bought it, so I did the belts and motors upgrade and got the CNC4Newbies risers and 7" Z axis. That z axis is a beast FWIW.

Anyway - first few test carves I was doing some vbit work on a 5" ish logo for a friend, and my X axis kept slipping so the carve ended up to the left or to the right. After the slip, the belt was loose, and I took a look, I realized that I hadn’t put the left side tensioning bolt/nut back. As such, I think the machine was pulling the belt holder along the track when it was hitting deeper pockets. During the troubleshooting process I also added zip ties and electrical tape to the belts near the brackets to hopefully ensure that the belts themselves wouldn’t slip.

After these changes, I ran a few board flattening files with a 1.5" surfacing bit (also figuring out that my z axis leaned forward a little bit causing ridges - fixes this with two of the m5 washers I had left over). Anyway - those jobs ran fine.

Also, this afternoon I cut a few fences out of 3/4" ply - cut 4 fences, 1/4" end mill going 100 in/min with .125 cut depth - absolutely no problems.

So I went back to my vbit carving. Immediate problem. 1/8" end mill, 40 in/min, cutting a 4.75" circle. As the bit was changing depth for the second pass (I think) I heard a thump and saw the x carriage/z axis shudder sort of and boom it was off. Not nearly as off as when the problem was happening yesterday pre-fixes, but off. The belt still seems to be tight tonight as well.

Since this was practice on plywood, i just jogged the machine up, reset x/y, and cut the circle again. No problems.

How likely is it that the belt is skipping over ridges on the pulley? Could the motor/pulley be skipping steps? What would cause these things to happen, if that’s in fact happening? Belt too tight maybe?

What should I check and how should I check it to see if that’s the issue - or possible find something else I’m not even thinking of?

Thanks in advance!

Not likely.

Does it always happen in the same general area on your X axis?

Check your wiring and connections for the X-axis stepper.

Same general area. I may have fixed it, and it was the dumbest of all reasons (I think). The new, larger stepper motor for the x axis was catching on the top of one of the zip ties on the cable chain. I rotated the buckle part of the zip tie down, and it moves freely now. Or at least seems to. Thanks!

This topic was automatically closed 90 days after the last reply. New replies are no longer allowed.