@Piotr_Sitko - if you want to rule out a case of backlash, i have managed to create a test that has managed to consistently show where my Y backlash was.
i re-did the belt on both pulleys - making sure it had equal pressure on both sides before tightening, and now the problem i had that was similar to yours - is gone.
i’d be happy to share the file if backlash is something you are still interested in investigating
@Tom_Keidar yep that looks like a good backlash test print, thanks for posting
@Ryan_Carlyle i’ve actually tried it and a few others off thingiverses. none of them showed any backlash (this test prints amazing actually).
so i went back to finish a needle-pin design for my wife and printed 6 of them… bam! backlash galore bright as daylight… (the waveform dead smack in the middle of the needle where slic3r starts the perimeter and then goes back)
put a few of them on the plate at different angles and completely diagnosed and removed all of the remaining backlash i had.
Two things were wrong, mostly it was old belts that I have put too much pressure and high temps, so they stretched. Also my rod is bend a little bit and I think Chinese that put it together forgot some washers so I added some and realigned the belts and cogs, they were out of alignment. Now my prints are much better and I don’t have to change scaling and dimensions anymore ! Thanks for the tip about new belts
