Coordination problem?

Hi hellstef,

if only x shift occurs it may also be a mechanical problem. Check the four bearing clamps for misalignment - when they is only a slight angle between them (e.g. because of the torsional force from tightening the bolts), the bearings can lock, causing the motor to stall. If in doubt, or if chattermarks are visible along the rod, detach the belt from the pulley, so that the carriage can slide freely from one end to the other. There should be no points with high friction or clamping.

Cheers,
kuraasu

dear kuraasu

yes that’s right, good idea, thanks, I had this problem on z axis because I screwed the bolts to strong, but x and y axis move slightly without the belt.

but looking at the blogs it seems only the x axis is affected. In y axis only the bed is moving, in x direction the bed AND the heavy stepper Motor (y axis) is moving. Since F=m*a the stepper Motor for x axis has to generate a large force F for acceleration a. This may be the reason for this Problem. So I suggest reducing accelerations in slic3r. Since I changed these parameters shifting never occured any more.

the second reason for shifting is resonance of the Printer itself, forces become high in case of resonance (and you can hear it). I could watch shifting while printing infill of a thin wall, so limitation of resonance frequency seems to make sense and was helpful in my case.

but: limiting acceleration and limiting resonance frequency means reduction of printing speed while printing small parts or infill.

so that’s enough for today.

cheers,
hellstef

Hi hellstef,

sure, the x axis motor has to move a larger mass than the y axis motor. I also know the acceleration settings and have set them (to even lower values; at the moment, anyway), but only as a last resort.

Some people here described upping their driver’s ampere setting in order to get rid of drive chain problems, that could just as well be purely mechanical. So it might be beneficial for some people to have a good look at those bearings.

Cheers,
kuraasu