Uneven circles

I have a mendelmax 1.5. I have been using it for over 1.5 years now with no problems of the sort I am going to speak of. When I print a circle, it prints with the left and right side having a flat portion. This does not happen on the front or the back of the print, just the sides. I have changed the belts and tightened them as tight as I could get them. I have also replaced the pulleys on both of the axis. I have also played with the z and y steps to try and solve the problem. It is not a problem with the slicer. I use Simplify3d and it happens with every print that contains screw holes and circles. I even tried the same print with repetier and Cura with the same results. I am at this time.......LOST!! Thanks in advance for any help with this.

Milt

Sounds like the x axis motor is having trouble with small reversals. If you take the belt off does the x-axis move freely? Does the x idler turn freely? If yes to both of those, it might be time to try a new motor on the x axis.

I have several motors standing by for another printer project. I will exchange my x motor for a new one and see what happens (tomorrow). Thanks for the rapid reply.

Milt

Sounds good, but I'd start by checking the axis moves freely. What micro-stepping are you using? This would be the classic case were the reduced per step torque could cause problems.

I am not sure exactly what stepping I am using, but I have all three sections under the stepper shorted with the shorting plugs. I believe this is the way it is supposed to be. I have also replaced the stepper driver with no change in the ability to create an acceptable circle.

Milt

OK...how about this one. My X carriage has 4 self centering sintered brass bearings on it. When I rebuilt the x axis a couple of weeks ago, I must have over tightened the bearing holders so that they were no longer able to self center. I loosened the holder bolts about 1 revolution and it seems to have, for the most part, solved the problem. Thank you very much Jamesk for all of the advice and help in getting this solved.

Milt

That's good news - glad you got it fixed.