Layer shifting

Yesterday my printer started to shift layers, but the problem is they get shifted at both x and y.

I have checked all pulleys, every single of them is sitting right where they should be, tight. Marked all of them with a marker pen and don’t see that they are moving. All motor drivers are set at about ~0.91V. All rods are oiled with sewing machine oil, can’t notice that they are moving with tension more than motors + belt tension.

Here is an image where they got shifted at Y, don’t have here one where they shift in both ways.

https://www.dropbox.com/s/2tumgqq0di0k4ep/Foto%202015-02-15%2013%2057%2042.jpg?dl=1

[quote=“kulla”]…can’t notice that they are moving with tension more than motors + belt tension…[/url][/quote]This issue is nearly always down to the stepper motors slipping due to one part of the XY axis being not parallel (causing greater resistance to the motor at one end) or the belts being too tight (same effect). Move your head gently with your hands in all directions - are you sure there isn’t any part that has greater resistance (especially at the ends)? Do any of the belts loosen as you move the head towards them? If so, you need to realign the rods until it moves completely smoothly for the full length of travel.

I have checked rods and they are parallel, I have used those calibration helpers from thingiverse for it.

The only thing that I see could be that I have overtighten belts, as everything else is ok as I can see it.

Belts doesn’t loosen at all when I move head.

The prints are always on the middle of the plate so there should tension on belts and rods be as low as possible

Do hear clicking when it starts to shift layers? If so, the stepper motors are struggling. Have you tried loosening the belts (undo the little V clamps a bit until the belt feels slack)?

No clicking sound, it looks like it just jumps over one step and continues like it should.

Will try to loosen the belts a bit and see what’s going to happen.

It seems that loosening tension of the belts did the trick. I did one 2hr print yesterday without problems, will test more today.

Tnx for help biscuitlad!

[quote=“kulla”]It seems that loosening tension of the belts did the trick. I did one 2hr print yesterday without problems, will test more today.

Tnx for help biscuitlad![/quote]You’re welcome, but make sure they’re not so loose that the belt could come free during a long print. Check them from time to time to make sure they’re not working themselves out of the clamp.