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Topic: Extruder drive stripping filament

I recently printed and installed the jigsaw mk4 (with mk3 accessory clip) extruder. I have been having an issue where about 1-2 hours into the print I go to check on it and the extruder gear has eaten part way through the filament and stopped pushing it into the heater barrel. My guess is that my spring is either just slightly too tight or not tight enough and ass the whole thing heats up thermal expansion pushes it to the point of not working. Any other possible causes and what should I do to fix it.

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Re: Extruder drive stripping filament

If this happens, it's because the spring is not tight enough. I tighten mine so about 3 threads are sticking out past the nut. If the spring is very tight, then the failure mode becomes the extruder skipping steps. If this happens, there's a clog/jam.

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Re: Extruder drive stripping filament

Thanks I'll give it a shot.

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Re: Extruder drive stripping filament

On mine I have the threads flush with the end of the screw and it works fine. The only time I ever ran into the skipping/stripping was when there was a partial clog and it wasn't allowing the plastic to exit fast enough, causing back pressure and only allowing it to feed if I pushed it by hand harder than heck.

There may be a slight difference from machine to machine though, but I would make sure not to tighten it so much as to deform the filament, it should just leave a nice line of 'teeth' marks.

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Re: Extruder drive stripping filament

This is my new issue, three times now I've started a new print and It keeps clogging and stripping.  It appears melted material is backtracking up the PEEK insulator and cooling.

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Re: Extruder drive stripping filament

So I have tried this print like 5 times.  Most recently the extruder seems to be stuttering trying to push the material through, and it's up to temperature.  I think what has happened is when I removed my first clog, I used a drill bit from the top side.  In doing so I must have stripped out the whole a little bit on the PEEk insulator and thats how the metled plastic is backtracking....

Any thoughts?

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Re: Extruder drive stripping filament

Screw the barrel into the PEEK more while hot.

8 (edited by tetrishead 2013-03-04 00:14:25)

Re: Extruder drive stripping filament

The partial clog in my extruder finally got bad enough to cause major problems once I tightened down the spring.
This is what it looks like when your extruder jams and forces filament out the side on a MK4 extruder.
I pulled out the filament and removed the clogged plastic. It works fine now.

Edit. Forgot image

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Re: Extruder drive stripping filament

nice modern art you got there

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