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Topic: Have you seen this extrusion problem?

I have my printer well tuned... or so I thought.  About 2 hours into my print, I seemed to have gotten a clog where the output got thinner.

I stopped, the job, reversed the feed out, made a clean cut on the line, and fed it back in.  Everything seemed fine and I started the job again.  I got farther the second time (3 hrs?  I was sleeping) ...  but the same problem happened.

This is PLA at 180 extrusion. Temperature is very stable on extrude.  Anyone else see this?  Bad material?  Something else?

http://virtualvector.com/wp-content/uploads/2013/06/20130613-211852.jpg

SD2, glass bed, MK5 setup with E3D lite extruder
NX and Solid Edge CAD user
PI, Galileo, and arduino hacker
Code Monkey and Twitter user @burhop

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Re: Have you seen this extrusion problem?

Inspecting the part, I seem to be extruding less and less material over the last inch of Z extrusion.

SD2, glass bed, MK5 setup with E3D lite extruder
NX and Solid Edge CAD user
PI, Galileo, and arduino hacker
Code Monkey and Twitter user @burhop

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Re: Have you seen this extrusion problem?

I'd say the gear is slipping and filament dust is building up and clogging it to the point where very little traction occurs.

Quick fix is to raise the temp by 5 degrees and see what happens.

Other things are filament not feeding easily from the spool.

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Re: Have you seen this extrusion problem?

Mark, you check your fan on extruder to see if working when print problem happened? You have a fan on electronics, especially steppers? Just curious.

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Re: Have you seen this extrusion problem?

This is exactly what happens when I forget to check if my extruder fan is spinning before starting a print.

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Re: Have you seen this extrusion problem?

PLA will be more susceptible to that problem as well.  It is also more prone to jamming if too much heat climbs into the PEEK.  PLA actually works better if it is running faster for this reason.  You might run into trouble if it is slowing down for cooling.  I would be better to turn off cooling and keep a fan on the print if you aren't already.

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Re: Have you seen this extrusion problem?

Thanks all.  I'll try/look at some of this. The hard part is that is works fine for a couple hours so the test cycle is going to be a bear :-(

SD2, glass bed, MK5 setup with E3D lite extruder
NX and Solid Edge CAD user
PI, Galileo, and arduino hacker
Code Monkey and Twitter user @burhop

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Re: Have you seen this extrusion problem?

Just to wrap up this thread in case anyone else has this problem....

I raised the temperature and tightened the spring on the feed.

When my model got to the top of my model it was putting out a lot of material on long runs and started "Skipping".  THat is, the motor was trying to push filament through but didn't seem to be able to. It would not do this during slow feed.

My best guess is that the filament could not melt fast enough so I raised the temperature to 195 (from 180).  I was able to finish the job. 

It is possible the spring wasn't tight enough causing it not to get a good grip on the filament.     There were a number of "chips" from the first couple tries.  Or, maybe I just needed a higher temp for long, high out put runs. Or, maybe I needed to do both.  Who knows.

In any case, it is working like a champ now.

SD2, glass bed, MK5 setup with E3D lite extruder
NX and Solid Edge CAD user
PI, Galileo, and arduino hacker
Code Monkey and Twitter user @burhop