since a couple days (if not weeks) I try to calibrate my CoreXY printer. It is a custom build based on VulcanosV2 on Instructables.
Going to conclusion first, I think there's something in firmware math which to me seems to be wrong.
But going to details...
I print a 50x50mm object, 45 degree on the bed. I use Simplify3D and Repetier-Host/Server.
After measurement I got a difference between x and y axis of about 0.2 mm.
So I tried to reduce this difference. First of all I tried to adjust the loose or tight of the belts.
For this I got a bit better results but still way over 0.1 mm. But one belt I had to tighten that much, I clearly see that my printer mechanics is way off of square. Also the print itself isn't square anymore!
Next I changed pulleys from right to left than motors from right to left... no difference.
Last I changed steps of A and B motor but still got the same. Not only the same, it does not even change the direction of difference.
A=160 steps, B=163 steps -> x=49.4mm, y=49,6mm
A=163 steps, B=160 steps -> x=49.4mm, y=49.6mm
If I look right this should not happen on CoreXY mechanics? Am I wrong?
What I also discovered: If I do extreme step change, both axis starts moving even for 45 degree movements.
For extreme step change I set A=160 steps and B=170 steps and vice versa. Both axis are moving. For sure I got a trapezoid, but it keeps same results. X still is the same amount smaller than Y for both settings.
So you see, I do not have any idea how to solve this issue.
Is there any setting were I can get to "swing" around 0 difference?
I also tested last dev firmware and FAST_COREXY. For release version there is no difference. For last dev version I do have serious issues with Z homing. X and Y home seems to work OK. But Z homes normally but after that it moves down about 20mm and I do not have an idea how to remove that "offset".
Sorry for long post. But I am a bit frustrated because I do not find any answers. To some 0.2mm or 0.1mm doesn't seem to be an issue. But I mainly print mechanical parts were this difference indeed is an issue.
best regards and thanks for reading,