[Résolu] Extrusion Problems  

RE: Extrusion Problems

That grinding sound means that there is a jam and it is not advancing the filament. You can also see bits of filament on the gears as it rotates. You can confirm this by lightly touching the filament coming off the spool as it loads. You'll feel it move through your fingers until it gets to the extruder and then even though the gears are moving the filament should no longer move.

This could be a couple of things. If you have not successfully extruded since assembly then you may have an alignment issue where the filament is not being guided into the PTFE tube under the gears correctly. You might be able to use the hex key alignment process (in the manual) to fix this, but you may have to disassemble the extruder. If you have been printing, then you most likely have a jam that may or may not be easy to fix.

In either case I would start of with:

1. Get a 50-100mm piece of filament to test with.
2. Remove the PTFE from the top of the extruder and tuck it out of the way.
3. In the Settings menu set the extruder temp to an appropriate value for the filament scrap you are using.
4. In Settings -> Move Axis move X and Z so the extruder is in the middle of both axes.
5. Go back to the Info screen and wait for the extruder to reach the set temp.
6. Go back into Settings and disable the steppers
7. Insert the filament through the gears until it won't go farther.

At this point it depends on how far the filament went. If it feels like it went just past the gears and stopped then either there is an alignment issue (if you've never printed) or the top of the PTFE is clogged. If you have never successfully extruded, stop here and look for and resolve any alignment issues.

If you have extruded in the past or the filament felt like it made it into the PTFE tube, apply firm pressure to the filament to try to keep feeding it in and push through any blockage. If that still does not work:

1. Raise the extruder temp to 250
2. Remove the nozzle.
3. Repeat trying to feed filament through.

If it's still not passing through you can try passing a small (less than 2mm) rod/pin in reverse to see if you can push the jam out that way. If not then you'll probably have to tear down the extruder to fix it.

While getting my MMU to work I had a jam where it lodged a 1cm chunk at the top of the PTFE tube and also had about 2" stuck in the heat break and had to tear the whole thing down to get it fixed.

RE: Extrusion Problems

Gnat, I have done this numerous times thinking that it is a clogged nozzle or extruder, but every time I pass filament it extrudes fine without any issues. I also do cold pulls to make sure and the tip comes out clean. 

RE: Extrusion Problems

Interesting. What happens if you disconnect the PTFE from the MMU and then feed filament through it to the extruder? Wondering if there is something with the PTFE connection that is causing an alignment issue. 

RE: Extrusion Problems

found the culprit, a faulty IR sensor

RE: Extrusion Problems

Glad you found it. They really need to do something about the IR sensor. For something that was supposed to be an improvement, it certainly causes a lot of grief...