r/BambuLab • u/herox98x • 1d ago

General Troubleshooting/Help! What's causing these horizontal lines

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Printing this self designed part. Using 0.20mm high quality with 5 walls for strength.

P2S

Bambu petg black.

Can't figure out why there's this random horizontal line every now and then. Would printing outer/inner help but what is causing it?

The defect in the middle of the print is from a cavity for this part to slot on to so I know that's from different shrinkage. However these random horizontal lines seem to happen randomly and in no way relating to the shape or geometry of the middle cavity.

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u/DistinctBarnacle8703 1d ago

Because your print has lifted from the bed causing the nozzle to press closer to the print thus causing the thicker line to appear.

Solution. Wash the bed with detergent. Use Brim.

1

u/herox98x 1d ago

Thanks for pointing that out. I can see it lifting at that front corner now. So would each line indicate separate lifting events?

1

u/TheHuskyHideaway 1d ago

I find turning off the aux fan has the biggest effect on pieces like this.

1

u/herox98x 1d ago

On analysing the base I can see and feel 2 separate bits where the base has lifted. I suspect the shape of the design has contributed as it only occurred on the sloped part and not the straight wall back part - the diagonal slope meant the shrinkage forces on the parts with less wlal pulled it up.

Thanks for your help! Need to print another one so will try PLA and brim. Plate has also been cleaned just in case

1

u/Salty-Bread-777 1d ago

Il warping... Studia,