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Odd layer shift with video  

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Alpha
(@alpha)
Estimable Member
Odd layer shift with video

Bit of an odd one, was printing overnight and there appears to have been an extreme layer shift for maybe 40-50 layers and then it carried on as before??

Any ideas about what might have caused this?

 

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Posted : 05/08/2019 6:05 am
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(@)
Illustrious Member
RE: Odd layer shift with video

Place a straight edge on the bottom of the part you pulled off the bed, the one with the shift.  I suspect you'll find it is NOT flat.

Large parts like that will warp.  Bed must be spotless (yours isn't, I see fingerprints); and the bed needs to be warmed up 5 to 10c to help keep the adhesion stable.

When the part warps, the nozzle crashes into it and stalls the motors N steps.  After the stall, the printer has lost track of where home is, so starts printing N steps away from where it should. 

 

ps: here's what a warp looks like:

 

 

This post was modified 5 years ago by --
Posted : 05/08/2019 7:27 pm
Alpha
(@alpha)
Estimable Member
Topic starter answered:
RE: Odd layer shift with video

Ah, great advice that makes total sense now - you're right, was being a bit lazy as fairly new pei sheet so thought I could get away with it...!

When you say warm up bed 5-10C, I assume you mean above the normal (it was standard 60C, so do you mean 65-70C?

Posted : 05/08/2019 8:25 pm
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(@)
Illustrious Member
RE: Odd layer shift with video
Posted by: katie.o

When you say warm up bed 5-10C, I assume you mean above the normal (it was standard 60C, so do you mean 65-70C?

Yes... I run 70c now when printing larger parts that have square corners.  I also wash the PEI well with soap and water before starting the print.  Once in a while I'll even keep the cooling fan down at 50%, hoping the part cools a bit slower.  I can't say this solves every print, but the frequency of failures is way down.

Posted : 06/08/2019 3:07 am
Peter M
(@peter-m)
Noble Member
RE: Odd layer shift with video

Big flat parts need a big brim, attached to the object.

Also you could do extra or if needed, use glue stick.

Clean the pei with dish soap 1x a week, and between print with alcohol, this for pla.

And first layer should be perfect, to stick better to the bed.

 

Also small parts need a brim and glue stick, if only a small part of the model is on the bed.

Posted : 06/08/2019 9:58 am
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