Hey all,
As I’m cutting a part, every layer down seems to shift the cutting by 1mm or so. The piece I’m cutting also includes an engraving and pocket feature and I am not getting this shift occuring on these features.
Happens only on the X-axis. Timing belt is tight. Speed is 8mm/s and depth of cut is 1mm.
Any advice?
The X axis has only the one motor, so it’s going to be a little more prone to resistance to movement. Sometimes you can bump up the motor current, and it’s OK.
Those steps look pretty regular, close to the same amount each time. This might be a loose grub screw, letting the motor turn a little extra in one direction. It’s worth checking that the grub screws (The screws on the pulley that hold it to the motor shaft) are tight.
Lastly, make sure that that the wheels on your LR aren’t sliding sideways. There’s usually a limit to how much this is possible, and it’s not very big, but it can present like this. Some people have put “rails” – just strips of wood inside the wheels of the LowRider to force it to keep on track, and this has worked well for them.
Try everything Dan says (especially tighten grub screw and use locktite) and if that doesn’t work try switching your milling direction and see if that makes a difference. Also try a <10% finishing pass and see it if it cleans up your initial rough cut pass or the final rough pass. You should be able to tell if you’ve got some backlash and/or play in your X or if you’ve got a skipping steps issue.
Hi Dan,
I think the rails in the Y Axis will be the solution, as I’m noticing the wheels are wanting to track off the table when I move a significant distance.
I’m guessing this is why I’m not getting any shift during the pocket cut, as it’s only small, where’s the part cut is reasonably long.
Also of note is that my spindle motor is heavy (2.2kw) so I think modifying the x axis to run 2 motors will be something I’ll need to do in the future. General movement doesn’t seem to struggle, I’ve got 2a motors and I’ve adjusted the driver voltages already.
[Solved] - Ended up being the LR wheels sliding sideways as you suggested. Installed some tracks and also tightened the rail clamps and the issue went away completely.
Thanks for your help.
