print defect

General LulzBot Mini
1

Hey guys,

I’ve been messing with flow rate and retraction distance to fix some print defects I’ve been seeing, but this defect is semi-new to me. Any suggestions on what to change to reduce it?

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Thanks
Jim

2

It’s intermittantly underextruding. That’s usually caused by an idler that is too loose or a small gear that is slipping on the extruder motor due to a loose setscrew. It can also be siezed bearings or a fillament path that is dragging dure to a pinch.

3

I tried tightening the idler and tightening the set screw. No improvement. Although the spots are in a different location this time.

4

I think i had that when I had too much retraction once.

5

That’s possible, if you have to much retraction you can have air bubbles in your molten filament.
Jim, please post your retraction settings.