LAyers getting shifted during printing

Hello,

I have recently finished building my K8400. I can’t get a first print working however.

For my first print I’m using the vertex logo sliced with repetierhost to a sd card.

The printer seems to build layer 0 okay, with seemingly nice precision.

When it changes layer the head skips to a new position, but that is too far, so the new layer gets shifted.
So, the layers arent being printed on top of each other.

I tried about 4 times with different software configurations. First I tried slic3r command line util on linux,
Then CuraEngine on linux. Then I tried upgrading the firmware on the k8400. After that I tried generating the sliceing on repetier host on windows.
(I dont really have a windows machine so its harder for me. I still havent figured out how to get the correct printer settings on linux)

I also tried making the x/y carriage move smoother by adjusting the belts. That seemed to improve the precision, but the layers still get shifted.

Any ideas what to try now? I could try bypassing the sd card, but I dont know how to get the correct printer settings on linux.

Hi, when I had the same problem it turned out to be the pulley on the stepper motor slipping. Because the grub screw is quite small (3mm) it can be difficult to get enough pressure to stop the pulley slipping across the flat of the motor spindle. I was wary of over tightening and stripping the aluminium thread on the pulley so I drilled a small recess in the motor spindly for the grub screw to locate in. I only the problem with one of my stepper motor.

Check all pulleys on X-Y if tightened, mark all pulleys.

See the methode to check, see my contribution here

viewtopic.php?f=62&t=13730

be carefull not to overtighten the pulleys as there is not much to ruin the thread.

As mentioned befor check the pulleys on the steppermotors

Thanks for all the advice!

I tightened the screws on the pulleys on the rods.

I lowered acceleration to 1000, and speed to 90.

This made me finally have a first decent print!

I havent tightened the screws on the motors yet, because that is a bit harder to do. I will try that next.