Had anyone experienced judder in the y-axis when cutting small areas quite slowly? I have a job which I run in mid-air to test and the judder in the y-axis is visible by watching the top of the spindle. It’s not caused by sticking V wheels or resistance on the tracks (I’ve stripped it down and checked all that) but more to do with the amplification of the stepper motors as they move the cutter in the small circle of the job.
Do stepper motors become less smooth with age I wonder? I’ve had my X-Carve for a couple of years now but I don’t use it a great deal but I do wonder.
I’ve made the X-axis more rigid by bolting the two rails together and although it still has some movement it’s nowhere near as wobbly as it used to be. The problem is the cause of the judder rather than the rigidity of the X-axis I think because when it judders it’s not actually cutting anything.
If you look closely at a circular file, many arcs are really a series of small straight lines. The machine is stopping at the end of each of these lines and the action of this on a very small circle could be causing the symptoms described.
I do not know what software you run but I use v carve which has a node editor that will let you see these lines and has options available to clean them up.
What you say sounds very likely the cause. Large circles don’t exhibit the same symptoms.
I use Fusion360 to draw the item and generate the gcode. I then use grblControl (Candle) to drive the X-Carve
I’ve just done a bit more reading on this subject and found an article that talks about “tolerance” and “smoothing” settings in Fusion 360 CAM. The default is 0.01mm so should I increase this or decrease it to reduce the judder? i.e set to 0.001mm or 0.1mm ?