Extreme Layer Shift???

[minuteman64 4]

Using Cura 4.13.1 with Anet A8 printer.  Got a strange print last night.  See photo.  Upper object(s) from previous print and show the way it was supposed to come out.  Lower object is what I got.  Same drawing for both prints.  Only settings for wall thickness and extruder temp were changed for mangled print.

 

I've read about layer shift - but this seems way out there.  Any ideas on what went wrong?  

[GregValiant 1,346]

I'm sure that isn't the way it was in the gcode.  It looks more like something got stuck (bed wiring, bowden tube), or the bed hit something.  Was the brim still affixed to the bed?

[Alain_D 5]

May be belt tension ?

[GregValiant 1,346]

That's an easy one to check.  It would have to be awfully loose, and then it didn't happen again.  The chances of it skipping that many teeth and then not doing it again are pretty low.

Did the power happen to go out?  Even a quick glitch could cause a stepper to lose position and then it just restarted where it thought it was.

 

 

[minuteman64 4]

Yeah, the more I thought about it the more it appeared to be a mechanical problem.

 

Brim was firmly fixed to bed - along with the portions of the model surrounded by the brim.  I'm pretty sure there was no power outage.  Checked this morning and the y-drive belt is pretty saggy.   

 

I'm going to check/adjust both belt tensions and also check for anything else loose/detached associated with the bed.  Then I'll give it another try.

[minuteman64 4]

Yeah, the more I thought about it the more it appeared to be a mechanical problem.

 

Brim was firmly fixed to bed - along with the portions of the model surrounded by the brim.  I'm pretty sure there was no power outage.  Checked this morning and the y-drive belt is pretty saggy.   

 

I'm going to check/adjust both belt tensions and also check for anything else loose/detached associated with the bed.  Then I'll give it another try.

[minuteman64 4]

I'm pretty sure it was the y-belt.  It had a visible sag and the adjuster was loose.  Tightened it up and re-printed and it came out OK.

 

Appreciate the tips.