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jonn
 jonn
(@jonn)
Eminent Member
Extruder flow problems

I have a problem I hope someone here can help me with.

The extruder keeps stuttering at higher speeds and prints come out lacking filament. The slow first layer is perfect, but from the 2nd layer, it's a mess. The video shows filament loading, first quick stuttering for 2-3 seconds, then slow easy flow. It stutters the same way when printing above the first layer. Anything printed below 25mm/s is fine.

The machine is a factory built MK3, it used to work like a charm.
The pulleys are aligned and I get the same result no matter what the lid tension is.
I've tested PLA and ABS, no change.
I've tried to cold pull a few times with no debris

Does anyone know how to fix this?

Thingiverse profile.
Posted : 30/01/2019 1:20 pm
bobstro
(@bobstro)
Illustrious Member
Re: Extruder flow problems


[...] The extruder keeps stuttering at higher speeds and prints come out lacking filament. The slow first layer is perfect, but from the 2nd layer, it's a mess. The video shows filament loading, first quick stuttering for 2-3 seconds, then slow easy flow. It stutters the same way when printing above the first layer. Anything printed below 25mm/s is fine.

Speed is often the culprit, but since you're getting those clicks on the initial load, I suspect you've got a problem in your extruder.

  • Are your extruder tensioning screws on the left tight enough? You want them to grip but not too tightly. Mine usually protrude about 1mm from the left housing when I've got them tightened down properly.

  • If they're adjusted properly, open up the extruder housing and use a light to inspect the feed path. Does the filament feed straight down from the lid, past the extruder gear and into the PTFE tube into the hotend? With the door open, I can feed a 1.5mm rod (or wrench) through the top past the gear and into the PTFE tube without obstruction.

  • Check the idler gear on the door. Does it spin freely?
  • If those are correct, I'd contact support. You may have a jam in the PTFE tube path or other more serious problem.

    My notes and disclaimers on 3D printing

    and miscellaneous other tech projects
    He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan

    Posted : 30/01/2019 2:14 pm
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