Extruder stops extruding filament after a while  

RE: Extruder stops extruding filament after a while

Now I can only prints 2 layers before I get clicking from the extruder stepper from too much pressure.

I've tried a bunch of things, I've read on various posts

- Disassembled the extruder (twice) looking for blockages

- Re-set the grub screw on the extruder stepper

- Ensured axle for idler wheel is correctly seated

-Upgraded firmware to the latest

-Fiddled with the idler door screw, increasing the bed temp and played with the Z-adjust to no avail.

When I load the filament, it extrudes smoothly, with no clicking of the extruder motor. Similarly for the first 2 layers. As soon as I start layer 3 the clicking begins and it stops feeding filament.

Since the first 2 layers are 'ok' I assume the idler door is correctly set. My assumption is the the first 2 layers are higher than expected so the higher the layer, the greater the error from the target height and thus increasing the pressure on the nozzle at higher layers which has less room to evacuate the filament which leads to the over-pressure clicking. I would assume that increasing the live-Z would address this, but it doesn't appear to.

I'd appreciate any ideas...

RE: Extruder stops extruding filament after a while

I don't know if you've done an extruder calibration test. (reset printer,preheat nozzle, mark 100mm on the filament. measuring from the top of the extruder assembly. then goto settings/move axies/ extruder and run it 100.)  she if its close. when its don't moving 100  you should see the mark around the same spot you measured from.

RE: Extruder stops extruding filament after a while

3rd layer probably turns on part cooling fan - check your fan duct is not pointed at the heater block instead of the nozzle tip.

RE: Extruder stops extruding filament after a while

After the next jam, UNLOAD the filament and take a photo of the melt end and post it here. 

RE: Extruder stops extruding filament after a while

Ok,

    This morning I ensured that the nozzle fan housing was tilted as far down (towards the nozzle) as possible. I did an initial test and had the same problem and noted that the fan didn't come on at the beginning of the 3rd layer, but it was a good idea. I did another test this evening and it got a few more layer farther, but then the same problem occurred and now I've manage to tear the PEI sheet on the removeable spring steal sheet because of the extra work to remove thin (failed) objects =(.

  Here is a picture after filament removal (PETG). You can see a slight indentation on both sides near where the allen key is that is where the extruder gears slipped. Otherwise there is just minor marking on the filament from the gears driving the filament into the hot end.

   Here is a picture after filament insertion (PETG).

I should note that as part of all testing and redoing everthing multiple times I changed the nozzle out from the Prusa Original. I didn't realize when I made the purchase (random amazon recommended variant 0.4mm) that the thread length was shorter. To compensate this meant I needed to screw the heatsink in closer to the hot end than I had previously so there was not gap between them within the hot end. 

Lastly, here is a picture of the extruder in case anyone sees anything notably out of whack. It doesn't appear that the nozzle fan air guide (shown behind the nozzle) is specifically designed to angle the air down to the nozzle and blowing somewhat over the heating block.

 I'm still trying to work out the extruder calibration. It was set to 95 by default and increasing it simply extruded some material and decreasing it retracted the filament. I din't see a way to extrude X amount.

Any more thoughts greatly appreciated.

RE: Extruder stops extruding filament after a while

I did the extruder test. Retracted it back to 0, marked the filament 100mm above the extruder and fed it to 100mm. When it was complete there was still about 5mm of space to the mark I'd made. I did the test twice, same result.

I took this to mean it wasn't extruding enough filament (which seems contrary to high-pressure failure) so I increased the feedrate from 100 to 105. I got 75% through a 1cmx1cmx1cm cube before it failed...again.

I'm starting to think I've unlocked some easter egg in the firmware thats a grand tour of everything that can go wrong with the printer...   😪 

RE: Extruder stops extruding filament after a while

That "new nozzle" is a cheap chinese knock off and not worth the brass it is made of (if it really is even brass).  Toss it, buy an authentic E3D-V6 1.75 nozzle.

There are too many problems with you hot end to begin.  First, get the E3D nozzle, then install it following E3D nozzle replacement instructions TO THE LETTER.

RE: Extruder stops extruding filament after a while

Alright,

    Ordered a E3D-V6 1.75 0.6mm nozzle, a collet clip and some v6 socks for the hot end. While I'm waiting on those I'll try replacing the old original Prusa nozzle and see if there is any notable different.

I appreciate the advice.

RE: Extruder stops extruding filament after a while

I switched back to the Prusa original nozzle last night and recalibrated everything and successfully printed a short 15 minute print followed by a 2hr one (both PLA). I can only assume that after a bad clog and disassembly, I poorly recalibrated it and then made things worse with switching the nozzle.

I'll still switch out for the e3d nozzle when it arrives, but I think I can close the topic (fingers crossed).

Thanks for all of the advice.

RE: Extruder stops extruding filament after a while

Posted by: paul.m19

Hi,

     I recently upgraded from the 2S to 2.5S and I'm having a terrible time getting it to print anything. The printer calibrates fine and prints fine (for the first 1/2 hour or so). If I unload and load the filament it test extrudes just fine again so it doesn't seem to be a blockage. I've tried changing the depth of the screw connected to the extrude idler door with no noticeable effect. I have the same effect with PLA and PETG.

When it stops extruding plastic, the printer just continues on its merry way as if it were extruding, but nothing comes out. I'd really appreciate some tips on what this might be as it feels like I've tried everything (including disassembling the extruder multiple times, swapping the nozzle, and cold pulling etc.). When it was a Mk2S, it was flawless.

Since reloading the filament lets it work again (for a while), I assume its something to do with the feeding of the filament, but there's not a lot to adjust in that department.

Any suggestions are appreciated.

Sincerely, Paul.

 

Here is a picture after filament removal (PETG). You can see a slight indentation on both sides near where the allen key is that is where the extruder gears slipped. Otherwise there is just minor marking on the filament from the gears driving the filament into the hot end.

RE: Extruder stops extruding filament after a while

I am not so sure it is the nozzle problem.  I am having the same problem.  I recently updated the firmware and I am having the exact same problem on a 3.5 hr print.  After an hour or so, the MMU clicks and the head stops extruding, but the printer keeps running as though it is extruding.  I have not changed a nozzle or anything.

Currently, I disconnected the power to the MMU, removed it, and I am trying the print without the MMU.  Old school spool on top of the frame style.  If the print comes out, that is just another problem I have had with the MMU2S.

PS.  I find this MMU is the most frustrating thing I have ever experienced.  So many things can go wrong.  I wish Prusa would come out with a dual extruder that works!  All I want to do is print with support material.

RE: Extruder stops extruding filament after a while

Well, I took off the MMU and had the same problem printing straight from the spool.  It quit extruding.  I was wrong the clicking was coming from the MMU.  It is coming from the extruder.  I want to revert back to the previous firmware, but don't have it.

RE: Extruder stops extruding filament after a while

Have you got any further with this?

I have the same problem. 

Was printing without issue and then it jammed like yours but continued moving. 

Unblocked the filament and now it won't get through more than an hour or so without stopping extrusion but keeps on moving