after quite a while of happy printing and producing parts I have encountered a weird issue with model shift.
An STL file, that I have printed many many times before, suddenly exhibited a shift in the Y axis of about 8mm at a rather high layer (about 96mm height), after almost 9 hours of printing.
Now, when that happened once, I didn't put too much thought into it, thought it might be a jumped belt tooth, or even just the cat pushing it a little.
A few other parts, and a few copies of this one printed flawlessly then, but then it happened again. Now I was curious, but not yet really worried.
I updated the software now to 2.12.
Now it happened a third time right after the second time and I'm starting to be seriously concerned - wasting so much time for an error in the last few minutes isn't
too enjoyable .
So I examined the parts and found that it always happened at the exact same layer. That alone, (and also together with looking at the y axis drive belt and finding it to be perfectly tight) eliminates any chances of a randomly slipping belt or any of the like for me. Then however, the model prints fine usually, so I doubt it is a problem with the STL either. Also, I can't relate it to a sudden change in the Software - it happened with 2.0 and 2.12. Someone mentioned errors like this happening with inadvertent rotation during calculation for printing - but wouldn't it be a 1 in 676 x 676, so 1 in 456976 chance of that happening at the very same layer 3 times? I think I've had this issue with another STL as well, totally different model and happened at a different height - since I wasn't aware of this behaviour though I have no real recollection wether it was a shift in the Y axis or something else, as I said, I only think it was.
But what is it then? I'm at a loss right now, has anyone else experienced an issue like this?
Some more info:
- The model is always the same, and has been an untouched STL file since months, printing fine most of the time
- The model is always printed in the exact same orientation, by importing the STL into UP and then placing it with place and rotate commands. It is always printed by itself, no other models in the print, centered on the build area.
- My Software3 was 2.0 and is 2.12 on Windows. I have updated to 2.12 before the last (3rd) occurrance error, before that I ran 2.0 since I got my UP in January. The Update didn't seem to change anything
- Printer is an UP Plus 2
Thanks a lot for your valued input!