Y-Axis wont stop at its end, round shapes turn into ovals stretched along the y axis
Sorry for the messy title but Im not sure about the vocabulary. The motor is always trying to run further than it is physically allowed, and makes a crrrrtsh sound. Is this what is called losing steps?
So for the background: I tried to print something. and it failed pretty badly. The object was laid on a side where i inserted a 0,2 mm extrusion to part of the footprint, because i thought since the layer height is exactly 0,2 mm, this would give me a little raise to later on wedge the print in a square alu profile.
Well it didnt work out, my slicer didnt add the support for the rest of the downward surface which was 0,2 mm higher and it just fked up.
It was an 8h job and i left the premise, so actually quite a bit of material accumulated over night, resulting in a big plastic clown hair mess.
I cleaned it up and got rid of as much as i could find of the remains and wanted to start another job.
Some gears. Round gears. During calibartion the printer hit the end of the y axis audibly, but finished the procedure. The only problem: the gears turned into ovals.
Now I tried calibrating it multiple times, but the process fails at the 3rd point (because of the y axis).
Only those two arguments occured to me, that could be a possible cause for this problem:
-firmware error: somewhere the stepangle or speed values of the y-axis motor must have changed, resulting in the motor trying to drive the normal distance but making to many turns
-some plastic is still somewhere stuck and keeps a sensor from correctly giving the end singal for the y axis
RE: Y-Axis wont stop at its end, round shapes turn into ovals stretched along the y axis
Ovoid circles are loose X or Y drive gears or belts skipping over the gear teeth.
Flat First: Drive gears must be tightened flat-first.
1) Start with both set screws fully loosened so the pulley is free to spin on the motor shaft.
2) Align one set screw dead center with the flat on the motor shaft, slowly tighten the screw until it fully contacts the flat surface.
3) Torque the flat set screw to spec.
4) Now tighten the jam set screw, and torque it to spec.
Once tightened, never touch the flat set screw unless the jam screw is first fully loosened.
Why Flat First? Set screws have flat ends. If you tighten the jam screw first the set screw on the shaft flat doesn't fully contact the shaft, only one small edge of the screw surface is biting. Reversing torques can easily shift the shaft to a position the flat screw no longer contacts the shaft. This lets the jam screw wriggle loose. And after a while, vibration loosens the screws until the gear is free to rotate.
RE: Y-Axis wont stop at its end, round shapes turn into ovals stretched along the y axis
thx for the advice, but is this Solution still right if the ovals are Perfect ovals? like symmetric and perfectly stretched only in the y-direction? because the Pictures looks more like a non Uniform cirle with flatternd sides.
RE: Y-Axis wont stop at its end, round shapes turn into ovals stretched along the y axis
a picture tells more than a thousand words:
https://1drv.ms/u/s!AKJs7gN-LQZVnCA
RE: Y-Axis wont stop at its end, round shapes turn into ovals stretched along the y axis
Since that isn't a photo of an actual print, the advice above stands. The only thing that will cause a true ellipse is a bad calibration . If you have run an XYZ calibration, successfully, the ellipse theory is difficult to consider. But you haven't finished a cal it seems. So the print isn't the issue, the calibration is the issue.
You should have said "I can't finish a calibration" - not "I am getting oval prints."
So a few questions:
What printer are you having problems with: make and model, please.
Explain in detail exactly what is happening during XYZ calibration. Step you take, what the printer is doing, etc. Any error messages.
RE: Y-Axis wont stop at its end, round shapes turn into ovals stretched along the y axis
lol ok here you go:
https://1drv.ms/b/s!AKJs7gN-LQZVnCk
the actual prints.
Its a prusa mk2.5 with mmu ver2
Well the auto calibration at the start of each print finished, and then the print turned out just like in the pictures. So i did the Calibration from the settings menu, and that one failed.
It does the z axis, the 2 points closest to the user (or the lcd screen), and then it tries to do the first point at the back. But it drives too far and hits the end of the axis, the motor does those crrrrtsh sounds and then the calibration fails.
I also tried the wizard, to the same outcome, but now i cant print anymore because the calibration is necessary to succeed for that.
The error message of the calibartion is "XYZ Calibration failed. Bed Calibration point was not found."
I cannot exclude the possibility of someone intentionally altering the configuration of the printer so that it wont work anymore at this point, so i guess the problem could be of a pretty fantastic nature
RE: Y-Axis wont stop at its end, round shapes turn into ovals stretched along the y axis
i just noticed there is yellow filament on the y-pulley gear... trying to get rid of it right now
RE: Y-Axis wont stop at its end, round shapes turn into ovals stretched along the y axis
ok the material is out... calibration is running... annnnnnnnnddddd.....
it worked! i might just be able to print again 🙂 i think my problem is solved now. thank you tim for your time and help!