RepRap Mendel with 6 gen electronics shift Y axis each layer ...

Hi, I have a Mendel reprap with gen 6 electronics and Repsnapper software. All axes work well, for example when I send Y10 the real Y axis move of 10mm.

I have a problem, when I print an object, each layer is shifted about 5mm in the Y axis direction.
Look this photo (print_test.stl after 4 layers) : [imageshack.us]

I think hardware and firmware works well because the first layer it's ok, it's possibile that repsnapper can't convert gcode correctly?

The only settings that I changed is "Downstream extrusion multiplier" because I have 1,75mm PLA filment insted 3mm.

Thanks!

More likely that your Y-axis motor pulley is slipping. Tighten the grub screw (if you have one) on the pulley or slow down the printing.

Thanks! This time I used bicomponent glue and it work well!

for me this was the belt climbin up the side of the gear (I have metal gears) and shifting by exaclty one belt tooth every time it hapened. It seemed to be speed dependent and only happened occasionaly but I saw it do it once so smoking gun. realigned the gear with the belt and made sure it ran in the centre and no more problems.

yipee