Layer Drifting  

Re: Layer Drifting

Did the part detach from the bed? (I assume not by looking at the picture, but worth asking.)

If not, something is not working right on your X assembly. Perhaps there is too much friction and the stepper motor can't push the X carriage around and skips steps (have you tried high power mode?), or perhaps the belt is too loose or too tight, or the pulley is too loose, or the belt is damaged, or the idle is not spinning freely, etc.

If it only happens at that particular Z height, then perhaps your Z rods are not perfectly straight and parallel which may be adding stress to the X assembly.

Note that the new firmware version has a new selftest that will try to check for problems with the Y and X axis, so you may want to run that. Otherwise, just visually inspect the printer (pulleys, belts, bearings, rods etc.) and see if anything is obviously wrong, then try to eliminate every possible cause one by one by running tests.

Re: Layer Drifting

Hi,
this can be caused by several things, however for now my question is: Are you printing using Silent or High power mode? Let us know 😉

Re: Layer Drifting

You may consider:
-Too much infill, try 6%, rectilinear fill
-Add the brim option when slicing
-Try printing tall, long parts warp bad
-You calibration is off, need to print closer to the bed, print the batman but only first layer, post a photo to this thread

Re: Layer Drifting

Hi,
this can be caused by several things, however for now my question is: Are you printing using Silent or High power mode? Let us know 😉

I am not using silent mode--just high power mode.

Re: Layer Drifting

Did the part detach from the bed? (I assume not by looking at the picture, but worth asking.)

If not, something is not working right on your X assembly. Perhaps there is too much friction and the stepper motor can't push the X carriage around and skips steps (have you tried high power mode?), or perhaps the belt is too loose or too tight, or the pulley is too loose, or the belt is damaged, or the idle is not spinning freely, etc.

If it only happens at that particular Z height, then perhaps your Z rods are not perfectly straight and parallel which may be adding stress to the X assembly.

Note that the new firmware version has a new selftest that will try to check for problems with the Y and X axis, so you may want to run that. Otherwise, just visually inspect the printer (pulleys, belts, bearings, rods etc.) and see if anything is obviously wrong, then try to eliminate every possible cause one by one by running tests.

The part did not detach from the bed. I stopped it when I saw it drifting.

I installed the latest firmware and ran the self diagnostic. Everything checked out ok.

Re: Layer Drifting

You may consider:
-Too much infill, try 6%, rectilinear fill
-Add the brim option when slicing
-Try printing tall, long parts warp bad
-You calibration is off, need to print closer to the bed, print the batman but only first layer, post a photo to this thread

OK. I'll try the settings you've suggested. Meanwhile, here is the first layer of the batman print:

What does that tell you?

Re: Layer Drifting

The right side looks too squished, while the left side looks like the nozzle wasn't close enough to the bed. This suggests a bed leveling problem. Try to play with the adjustments, or see if you can find the cause of the problem (eg the threaded rods are not all the way down in the slots of the metal frame?).

Re: Layer Drifting

Thanks Gab. Appreciate the help. I bought the printer pre-assembled, so I'm mostly at a loss as to what kind of adjustments I can make and how to make them. Incidentally, I went ahead and tried to print the whole batman symbol at which point I had the same problem. I then just re-calibrated the Z axis and then reprinted and it printed fine the second time. Thinking the Z calibration might help with this other print, I tried it again, but still got the same result. Do you think that it's a bed leveling issue even though the batman symbol printed fine after calibration?

Re: Layer Drifting

Are you raising he print head to z=100 before preheating? If the pinda get too warm it will get bad values.

Try printing tall objects from the SD card, the vase is fast.

Is that ABS orange or PLA orange? Are you using the stuff from Prusa of some other vendor?

With the printer off, move the printbed by hand slow as to not damage the electronics. Are any of the zip ties under the print bed catching on the z frame?

Is the spool holder too tight, it should rotate freely. Try cutting a length of it and print w/o the spool holder, zip tie the length to the frame for the batman test.

Re: Layer Drifting

I have been (hopefully) having a few problems with layer drift on my machine over the past week or so. What I think the problem was is that the Y-axis pulley holder had rotated upwards towards the bed meaning the teeth on the Y-axis belt were catching on the Y-axis belt holder attached to the bed. Hopefully that makes sense not with my machine currently so can't take any pics.

Fix was a simple rotate the pulley holder so the belt runs nicely then re-tighten. So far seems to printing back printing at normal Prusa standard. When I get some time I might have a go at designing up a pulley holder that attaches at two points so can't rotate.

Re: Layer Drifting

I bought the printer pre-assembled, so I'm mostly at a loss as to what kind of adjustments I can make and how to make them.

In the menu, under calibration, you have options to adjust the bed leveling. It should be explained in the manual.

About inconsistent Z calibration results - I will repeat that the PINDA probe is quite affected by temperature, so you need to start the calibrations always at the same temperature to improve consistency.

Re: Layer Drifting

Are you raising he print head to z=100 before preheating? If the pinda get too warm it will get bad values.

No, I will try this

Try printing tall objects from the SD card, the vase is fast.

The vase I see on the card suggests it's a 5 hour print. Is that a fast print, or did you mean a different one?

Is that ABS orange or PLA orange? Are you using the stuff from Prusa of some other vendor?

All of my filaments currently are PLA. The orange one you see is from Hatchbox, however, the white PLA you see in my batman logo images is from Prusa and I'm having the same problem with it.

With the printer off, move the printbed by hand slow as to not damage the electronics. Are any of the zip ties under the print bed catching on the z frame?

It doesn't look like it.

Is the spool holder too tight, it should rotate freely. Try cutting a length of it and print w/o the spool holder, zip tie the length to the frame for the batman test.

The spool holder seems fine, but I'll try that.

Re: Layer Drifting

I have been (hopefully) having a few problems with layer drift on my machine over the past week or so. What I think the problem was is that the Y-axis pulley holder had rotated upwards towards the bed meaning the teeth on the Y-axis belt were catching on the Y-axis belt holder attached to the bed. Hopefully that makes sense not with my machine currently so can't take any pics.

Fix was a simple rotate the pulley holder so the belt runs nicely then re-tighten. So far seems to printing back printing at normal Prusa standard. When I get some time I might have a go at designing up a pulley holder that attaches at two points so can't rotate.

I'm not completely sure I understand, but it doesn't look like I'm having the same issue. Is this the pulley you're referring to?

Re: Layer Drifting

In the menu, under calibration, you have options to adjust the bed leveling. It should be explained in the manual.

I ran the bed leveling calibration in Settings | Calibration, but everything seems to check out

About inconsistent Z calibration results - I will repeat that the PINDA probe is quite affected by temperature, so you need to start the calibrations always at the same temperature to improve consistency.

Sorry, I don't know what you mean here. Should I preheat before trying to calibrate? Or should it always be cold? What's the best practice for being consistent?

Thanks again.

Re: Layer Drifting

Always start cold is the easiest way - just make sure the extruder is far away from the bed when the bed is preheating.

Re: Layer Drifting

I'm not completely sure I understand, but it doesn't look like I'm having the same issue. Is this the pulley you're referring to?

My fault for explaining without pics apologies, I have borrowed some from the instructions this time. No not the motor end the other end.

As you can see there isn't a great deal of space between the lower part of the belt and the printed part attached to the heated bed. Ignore the arrow in this pic, had to borrow images from the instructions as still away at the moment.

I have a feeling that my belt isn't quite tight enough and the pulley mount has either been knocked or moved over time. But fingers crossed since moving it back to where it should be I haven't had any issues with layer shift.

Re: Layer Drifting

Finally!

I was able to get it to print! I don't think I can rule out that there is something not right with my printer, however, what I ended up doing was simply rotating the part in slic3r 90 degrees on the z axis so that it was printing its length on the y axis instead of the x axis. It printed perfectly.

So, thanks for all the feedback and help. I learned a ton. Appreciate it.

-Matt