buckles on the surface

[gr5 2,167]

Sometimes a belt will slip on a pulley by one or two teeth - what happens is now the two blocks on the sides are not opposite each other and the rods are not perpendicular. This adds quite a bit to the resistance. Test it by pushing the blocks all the way to one end to see if they both stop at the same spot. Also by just looking from above to see if it looks perpendicular. Fix it by loosening the set screws in the pulleys re-align at the one end or the other and re-tighten. Tighten the hell out of those set screws - the shaft of the hex tool should twist slightly.

[GeorgB 0]

@neotko: that was my first idea as well, so that is done!

@gr5: your tip was good: for the movement back/forth the blocks had an offset of 2mm. I opened the set screws and changed that. The pity: I did not feel a difference in the resistance when I move the axes... I printed now the same part twice with 90° turned. The result was not very different between both. So that says that my theory of the resistance of the axes is not probably the case - it would be unlikely that both axes have the same issue!

I have now tried to improve the extrusion (cleaned the nozzle accurately and changed to a better flowing filament). That made a difference the buckles are now smaller - but still there. The jpg shows the 90° turned examples..

By working on the pulleys I saw the dust on the motors. I can also see that some dust is hanging on the belts. The belt is touching the side of the pulley, that creates probably the dust. I know it is more or less impossible to bring the belt exactly in the middle of the pulley, it always move to one side.

Do you also have this dust, means some abrasion from the belts?

[gr5 2,167]

I have 3 printers. No dust. I had that kind of dust on my UMO the first week I owned it and I learned that the belt was rubbing on the wood - the pulley on the motor was too far down the shaft - I needed to move the pulley closer to the motor so it was almost touching.

But I think you might have a different issue here. One problem is you have 3 pulleys above that motor I think. Still there is more dust closer to this belt in the image so I'm guessing that's the belt that is rubbing somewhere.