Printer Layershifting

Hello Printers,

Ive got an GermanRepRap Neo which has a printrboard rev d on board.

Ive got layershifting several times a print ans checked the mechanics, the pulleys, the
Steppercurrent (which i even dialed up a bit) but there is allways the same problem.

Once in a while there is a layershift from 2-5mm in only one axis.

I tried turning the object, then it shift on the other axis. So i think there is a slicerproblem or stl.

Prints with cura work out perfectly allmost everytime but with slic3r
It shifts allmosts everytime. I tried slowing the print down and it doesnt help.

Even when i do 80mm/s for.non print moves it shifts...

The steppers dont get hot and i even cool the whole printrboard.

I even do z-hop now but no change.

Does anyone have a clue?

The problem accured two weeks ago and i did not change the acceleration or such things.

Lord_Vader

Edited 1 time(s). Last edit at 04/08/2015 03:57PM by Lord_Vader.

80mm/s moves are pretty fast, for some printers. Try slowing those down. If that fixes it, either tighten your belts or increase your stepper voltage. If it doesn't, run the gcode through gcode.ws and look for weird breaks. If you see nothing wrong, try messing with Slic3r's acceleration.

Is it belt driven? One thing I have seen before is if you dont have the motor with the flat section on the shaft, it doesn't matter how tight you make the grub screws, it can still spin on a round shaft after time. Usually this can be seen when you take the pulley off, and see scratch marks around the motor shaft where the grub screws have been. (this happened once with my extruder also early on wher i thought it was skipping steps, but it was actually slipping) If I get motors with round shafts, I usually grind a nice flat edge on them, and when installing the grub screws, ensure that one grub screw is directly on the flat edge, that way there is no chance of the pulley slipping (or the need to over tighten the grub screw till it breaks) especially at the speeds you are talking about.

Hi,

thank you for your help i allready checked the belts (two for X, one for Y) and tightend them. The pulleys are tightend down.
The steppercurrent was increased and a bigger fan was mounted towards the printrboard.

The original movespeed is 150mm/s. And it did that very well. The bearings and rods are already new and i checked them again (it didnt shift even with worn bearings).

Now i did an experiment. I set the infill to 0° instead of 45° and that works fine.
So its no mechanical problem is it? I hope i get my heatsinks soon, then i will place them on the stepperdrivers and the other chips.
Thou they dont get that warm....

I never changes the slic3r acceleration settings. What does it do? Does it temporarily change the printer-internal settings or does it handle that via gcode?
Like I said, nothing was changed to the axis' or the firmware.

Had the same type of problem would shift at different places, I replaced drivers, motors and ramps. what it turned out to be was Sic3er. I found this out by printing a piece that I had slice a while ago it printed out fine. then re-silced the same part and it would shift. deleted Sil3er reinstalled and the shifting stopped. hope this helps.