Final step: Extruders won't extrude

Help eachother out with assembly problems.
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kerog
Posts: 117
Joined: Mon Jun 09, 2014 1:54 am

Final step: Extruders won't extrude

Post by kerog »

Got all the way through assembly and up to the point where I was finally going to try an actual print. But I couldn't get the filament to feed into either extruder. I could see the motor turning through the fan, so I know that's working. I tried increasing and decreasing the tension, but neither way seemed to make any difference.

Anyone have any ideas as to what's going on? Any suggested troubleshooting steps? Could the feed hole somehow be misaligned with the intake into the hot end?

Am I likely to get any help from support? Haven't gotten any response at all from two earlier emails I sent.

Dreide
Posts: 176
Joined: Sun Sep 29, 2013 12:32 am
Location: Lausanne, Switzerland

Post by Dreide »

Shine a light from the side (through the fan) and then look down through the filament feed hole and see how things are aligned. Do you see a gap between the extruder wheel and the bearing? And viewing further through this gap, do you see the extruder inlet? The extruder wheel must not be in the way of the view/filament by too much (and not by too little either).
Regarding the tension setting, try to start with a loose tension by turning the screw clock-wise. Then feed the filament up to the extruder wheel and, while starting the extruder motor, help the feeder by pushing the filament manually further in. If it doesn't work, don't let the extruder wheel grind on the filament for long. Rather pull the filament out, cut off the tip, and try again. It might help to cut the filament at an angle. Ah, does the extruder motor actually rotate in the right direction?
It might be difficult to loosen the tension enough as the thin nut holding the washer stack easily slips in its recess. Using a thick nut instead of a thin nut helps (step #51), but exchanging this nut requires the whole print head to be disassembled. Without disassembling the head, you can also remove the screw, pull out one of the crinkled washers from the stack, and put the screw back in place.
Felix 2.0->3.0dual * Repetier (host+firmware) * KISSlicer Pro, Simplify3D * Cubify Design

kerog
Posts: 117
Joined: Mon Jun 09, 2014 1:54 am

Post by kerog »

Thanks for the suggestions! I did confirm that the motor turns the wheel in the correct direction. The diagonal cut sounds like a promising thing to try. I wonder if anyone has a photo of how far the tensioning bit sticks out when properly set for their machine, just to give me a general reference.

I have the whole assembly open right now, as I was trying to troubleshoot why one of the bolts from step 67 wouldn't tighten. Turns out one of the assembly end pieces was defective, so it wasn't grabbing the nut properly. I confirmed with the Felix folks, and they are sending me a replacement. Anyway, now that I have the thing open, but still wired, I figure I should be able to use the Repetier manual controls to run filament through the extruder wheel (but not into the hot end, which will be out of the way). Does this sound like a reasonable troubleshooting step? Or is there something about having the assembly open that would make this a bad idea?

Dreide
Posts: 176
Joined: Sun Sep 29, 2013 12:32 am
Location: Lausanne, Switzerland

Post by Dreide »

kerog wrote:I wonder if anyone has a photo of how far the tensioning bit sticks out when properly set for their machine, just to give me a general reference.
Unfortunately, the setting is rather sensitive (IMHO a design flaw of the tensionner due to the tight coupling between tension and exact filament diameter), so a picture would not be so conclusive, I guess.
kerog wrote:Anyway, now that I have the thing open, but still wired, I figure I should be able to use the Repetier manual controls to run filament through the extruder wheel (but not into the hot end, which will be out of the way). Does this sound like a reasonable troubleshooting step? Or is there something about having the assembly open that would make this a bad idea?
Nothing speaks against it. Note that you have to heat the extruder in order to extrude from within Repetier host (this is for preventing cold extrusion). So either put the extruder where it does not burn into some material or use the LCD to control the extruder motor (at least with the Repetier firmware I have, this works without heating). Obviously, this does not allow you to check whether the alignment of the extruder with the feeder is causing the problem.
Felix 2.0->3.0dual * Repetier (host+firmware) * KISSlicer Pro, Simplify3D * Cubify Design

kerog
Posts: 117
Joined: Mon Jun 09, 2014 1:54 am

Post by kerog »

Note that you have to heat the extruder in order to extrude from within Repetier host (this is for preventing cold extrusion). So either put the extruder where it does not burn into some material or use the LCD to control the extruder motor (at least with the Repetier firmware I have, this works without heating).
I had thought about that, and was thinking I would temporarily change the extruder set temperature.

kerog
Posts: 117
Joined: Mon Jun 09, 2014 1:54 am

Post by kerog »

With the hot ends out of the way, I was able to visually get the extrusion working. I had to tighten the tension more than I had expected, but now it is working.

Dreide
Posts: 176
Joined: Sun Sep 29, 2013 12:32 am
Location: Lausanne, Switzerland

Post by Dreide »

You mean tighten the tension or tighten the tensioner screw?
Felix 2.0->3.0dual * Repetier (host+firmware) * KISSlicer Pro, Simplify3D * Cubify Design

kerog
Posts: 117
Joined: Mon Jun 09, 2014 1:54 am

Post by kerog »

I mean tighten the bolt that controls the tension on the filament feed.

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