Weird judder on curved path

So I am getting weird judder on my shapeoko when doing oval paths. Checked Gcode in openSCAM and it looks fine. Can anyone suggest what is going on? It is not very visible in the video but you can hear it, the higher pitched noise blips at certain intervals along the curve.


I’m not sure if I hear or see anything unusual. What you might be hearing are the steppers resonating in such a way that it produces a higher frequency audible noise. This typically happens when there is a multi-axis move and one axis is moving a lot more than the other(s). So in an oval path, this would occur near both sides of each apex for a total of 8 times.

If the machine is drawing or cutting the oval shape correctly, then there shouldn’t be anything wrong with the machine.

Well since posting this thread there has been a development. It started missing steps after some use (2 small jobs) and I have noticed that the chips on the controller are getting very hot. The right stepper motor driver is particularly hot and the motor itself is getting warmer than the one on the left of the machine.

Have contacted support and am awaiting a response. I thought maybe my powersupply wasn’t powerful enough as it is only 5 amps, is this the case with other shapeoko 3 users?

5 Amps is w/in the ideal range of 4.2 – 6 Amps:

Check to make certain that your board is adequately seated against the heat sink, and that in turn mates up against the extrusion?

Have you tried installing and using the provided fan for cooling?

Okay so I can cross that off as an issue, thank you!

Hmm good point, I might check the thermal compound is well applied and I might replace it with some arctic silver paste left over from a recent pc build.

Yes I installed the fan just now and seems to have helped a bit, still hot to the touch though (used my pinky to avoid shorting any nearby components).

When the machine is idle the steppers do make a lot of noise, medium pitch whining noise?! My shapeoko 2 (with nema 23s also) didn’t make anywhere near as much noise!

Edward replied to my support query and said that the driers do get hot enough (to potentially burn you) before going into thermal overload so that is reassuring that I am not damaging anything!