Larger PETG part, extreme layer shifting (Over 50mm up and 20mm right)

[TTVert]

This is the largest item I printed on PETG and it's also the first one w/ my new microswiss all metal hot end. I have a maker select V2. I had printhead at 260 and bed at 60. The print not only shifted up gradually it went left. The bottom layers remained in place so it didn't warp and deboned from the bed, the top layers actually moved. The bed is moving freely w/o any binding anywhere. I've never seen this before and would love any insight on this. I may try the print in PLA to see if it happens again but that's a lot of wasted material. The layers are all well bonded, just severely shifted. I also have no idea why there is a blob on it either, the printhead shifts up and away from the job when the print is completed to prevent any oozing onto the printed item.Any ideas what could cause this?Dave

[curious aardvark]

check belt tension and particular that the drive gear grub screws are tight and that the gears aren't loose.

That's usually the source of this kind of problem.

[TTVert]

check belt tension and particular that the drive gear grub screws are tight and that the gears aren't loose.

That's usually the source of this kind of problem.

Thank you, I had checked all mechanicals. I determined what had happened is during my first test print a bunch of excess ASA got between the printhead and the silicone sock as well as my fan shroud. As the printhead was heating it'd gradually melt back onto the prints and solidify. That is what those blobs were. I only discovered this when I changed to a different color filament and was seeing the blobs were the old color. That was the ah ha moment. Those blobs would solidify, the printhead would crash into them and throw off the sync of printhead vs. coordinates so it never knew where it really was after that collision. if I was in here w/ the printer when it happened I would have clearly heard it but I wasn't. Actually decided it was better to replace the heater block at this point as it was completely caked in ASA.


Dave