1 Topic by Mikelangelo

  • Mikelangelo
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  • From: Denver
  • Registered: 2016-10-17
  • Posts: 6

Topic: Bizarre inconsistent extrusion failure

I have started experimenting with printing very small layer heights to get some more detail out of my parts. I printed a part at 0.05mm layer height over the weekend and came back to some results that I was not expecting. The part completed, but has odd repetitive gaps in the walls and inconsistent blotching in the top surfaces (both seen below).

I've never run into or seen the wall inconsistencies, but I've seen something similar to the top layer inconsistencies from either the nozzle being too cold or under extruding occurring.

I'm wondering has ever seen the wall inconsistencies, and if so was it due to trying to print at a layer height that was too small for the printer? Or was it related to extrusion temp or rate?

The part is from ABS that I have been using for awhile, but this part is from a new spool of it.

I'm printing a test print today to make sure there wasn't a mechanical failure in the printer causing it, but so far it looks pretty good.

Thanks!

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2 Reply by wagnmkr

  • wagnmkr
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  • From: Lindsay, Ontario, Canada
  • Registered: 2016-07-16
  • Posts: 110

Re: Bizarre inconsistent extrusion failure

I am by no means an expert, but that looks like filament starvation. If you are using a small fill%, then there is just not the material to cover the holes.

I was cut out to be rich ... but ... I was sewn up all wrong!
Wanhao Duplicator I3 Plus with glass bed, MK10 All Metal Hot End

3 Reply by JeremyLGSiegfried

  • JeremyLGSiegfried
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  • Registered: 2016-11-17
  • Posts: 87

Re: Bizarre inconsistent extrusion failure

I'd say +1 on the filament starvation, I had this happen when I was still adjusting the extruder's ability to grip the filament.
Are you using a geared (reduced) extruder? You want a higher step/mm resolution when working with smaller nozzle/layer height sizes. It reduces the "pulsing" effect of the stepper motor.

Filastruder 2607 w/ Filawinder @1.75mm.
Dual-extruder MaxMicron Prusa Mendel: RAMPS 1.4 w/ Repetier Firmware+Full Graphic LCD Controller, stock hotends, 3Dator extruders w/ MK8 gears, insulated enclosure w/ 2 heat lamps, RPi 2B w/ Repetier Server.
0.1-0.2mm layer height, heated bed w/ PEI surface, inductive-sensor autolevel, 0.5mm to 0.2mm nozzle diameters.