Layer shift issue
OK any guidance on what is causing this shifting, these are all supposed to be straight cylinders. This is only happening on this specific STL/gcode, nothing else. I do all my design work in OpenSCAD and last time this happened I just re-rendered/recompiled the scad into STL and then re-sliced this new STL, and the problem went away, no idea why. But doesn't seem to help here. Any ideas what is going on?
Since I've never had much luck attaching anything here, even zip files, I've uploaded the zip to my web site and you can download it from https://supergeek.us/HandVacuum.zip
This looks like a mechanical issue:
First, with the power off, move the axes by hand; are they smooth? Does the resistance stay the same over the whole range?
Clean and lubricate the smooth rods, check they are not damaged/scratched. Check the idler pulleys are not clogged, out of line, or damaged (loosen the belts and try turning them with your fingertip, are they smooth?)
With the belts loose try turning the stepper motors by hand; you will feel the steps but otherwise, are they smooth?
Retighten the belts until they just begins to make a low musical note when plucked...
Make your next print this:
https://www.prusaprinters.org/prints/46639-tension-meter-for-the-gt2-belts-of-i3-mk3s-or-prus
It MUST be printed in Prusament PETG or the spring tension will be wrong.
Let us know how you get on.
Cheerio,