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CJSHayward
(@cjshayward)
Eminent Member
Plastic not feeding in extruder

I printed PETG successfully and had a blockage switching to PLA. I replaced the nozzle, and it has gotten most of the way with PLA being inserted in far enough to catch on the feeder.

I am currently getting zero extrusion after replacing the nozzle.

Furthermore, to my surprise, the old nozzle appears to be either mostly or completely empty. I inserted a toothpick into the old nozzle's inward hole, expecting to be blocked at most 1-2mm in, and the toothpick went in as far as it could easily go--I didn't "touch bottom" before the hole stopped the toothpick's easy motion.

Now I have made a couple of attempts at printing a PLA 75mmx75mm test square, and nothing seems to really extruding. I'm not getting spaghetti; I can look and see the nozzle without anything extruding.

What kind of diagnostics would be helpful to give here?

Thanks,

I invite you to visit my website at CJSHayward.com and my bookshelf at CJSHayward.com/books....
Posted : 13/06/2021 9:35 pm
cwbullet
(@cwbullet)
Illustrious Member
RE: Plastic not feeding in extruder

Is the filament drive gear  chewing up the filament?  If so, try reducing the  tension on the idler spring.  

If you remove the Bowden tube and heat to the filament then, can you hand extrude filament?

--------------------
Chuck H
3D Printer Review Blog...
Posted : 13/06/2021 9:53 pm
CJSHayward
(@cjshayward)
Eminent Member
Topic starter answered:
RE: Plastic not feeding in extruder

@cwbullet

I tried to search for the two procedures you mentioned, but the website search results were unreadably garbled. I quote the first below.

Could you post links to good posts or threads on adjusting the tension on the idler spring? Is the Bowden tube the metal nozzle or something else?

Sorry for asking you to do busy work, but could you point me to threads/posts that explain how to do the adjustments you mentioned?

Thanks,

# Post Title Result Info Date User Forum
  MK3S: Removal of Stuck M3x40 Extruder-idler Tension Screw   59 relevance 1 year ago eddycurr Hardware, firmware and software help
  What could prevent simple unthreading of class="wpf-sword wpfcl-b">the M3x40 Extruder-idler tension screw/spring unit from class="wpf-sword wpfcl-b">the M3n nut mounted in class="wpf-sword wpfcl-b">the printed Extruder-idler bracket on a 13 month-old MK3S w/ an est 1,200+ print hours?  class="wpf-sword wpfcl-b">the task SEEMS like it should be quick and trouble-free, but instead appears to be very close to class="wpf-sword wpfcl-b">the point where drilling out class="wpf-sword wpfcl-b">the head or nut of class="wpf-sword wpfcl-b">the tensioner assy and perhaps replacing class="wpf-sword wpfcl-b">the E-idler brkt becomes necessary. I am asking on behalf of class="wpf-sword wpfcl-b">the owner. I had no part in assembly of class="wpf-sword wpfcl-b">the machine. From examination of text and photos in Step 19 and Steps 27-32 of class="wpf-sword wpfcl-b">the following PRUSA document "3. E-axis assembly"  https://help.prusa3d.com/en/guide/3-e-axis-assembly_55136  I have come to class="wpf-sword wpfcl-b">the belief that:- class="wpf-sword wpfcl-b">the tension screw/spring unit fits into a deeply counter-sunk hole in class="wpf-sword wpfcl-b">the printed Hotend Assembly.- class="wpf-sword wpfcl-b">the spring seats against class="wpf-sword wpfcl-b">the shoulder of class="wpf-sword wpfcl-b">the Hotend's counter-sunk hole- class="wpf-sword wpfcl-b">the end of class="wpf-sword wpfcl-b">the tension screw passes out class="wpf-sword wpfcl-b">the right side of class="wpf-sword wpfcl-b">the Hotend's hole into class="wpf-sword wpfcl-b">the cavity for class="wpf-sword wpfcl-b">theExtruder-idler bracket- When class="wpf-sword wpfcl-b">the Extruder-idler bracket is in place, class="wpf-sword wpfcl-b">the end of class="wpf-sword wpfcl-b">the tension screw passes through class="wpf-sword wpfcl-b">the inboard sideof class="wpf-sword wpfcl-b">the screw hole in class="wpf-sword wpfcl-b">the Extruder-idler bracket to engage with class="wpf-sword wpfcl-b">the M3n nut mounted in class="wpf-sword wpfcl-b">the molded hex pocketon class="wpf-sword wpfcl-b">the outboard side.- class="wpf-sword wpfcl-b">the M3n nut appears to have a conventional thread with no provisions for 'locking' (ie: not a NyLock/Stover nut) On examination, about 1 - 1-1/2 threads of class="wpf-sword wpfcl-b">the M3x40 were protruding out from class="wpf-sword wpfcl-b">the M3n nut. It was NOT possible to turn class="wpf-sword wpfcl-b">the M3x40 CCW, but it WAS possible to turn it CW perhaps 1/3 turn (no filament in place) and class="wpf-sword wpfcl-b">then 1/3 CCW back to class="wpf-sword wpfcl-b">the initial position. The hex socket on class="wpf-sword wpfcl-b">the M3x40 is damaged/deformed from class="wpf-sword wpfcl-b">the owner's efforts. class="wpf-sword wpfcl-b">the torque required for class="wpf-sword wpfcl-b">the movement described above has further disfigured class="wpf-sword wpfcl-b">the socket. I noticed what I thought might be a small amount of metal oxide on class="wpf-sword wpfcl-b">the outwardly sloped lower side of class="wpf-sword wpfcl-b">the cavity in class="wpf-sword wpfcl-b">the Hotend Assembly while peering up at class="wpf-sword wpfcl-b">the bottom gap between class="wpf-sword wpfcl-b">the Hotend & Extruder-idler pieces.  class="wpf-sword wpfcl-b">the owner later suggested that what I saw might be filament residu
I invite you to visit my website at CJSHayward.com and my bookshelf at CJSHayward.com/books....
Posted : 26/06/2021 4:27 pm
cwbullet
(@cwbullet)
Illustrious Member
RE: Plastic not feeding in extruder

@cjshayward

https://help.prusa3d.com/en/article/idler-screw-tension_177367/

I just bearly tighten it.  It might be the issue, but it is a place to start.  Too loose and you get under extrusion and can get clicking.  Too tight and it will chew on the filament until you get under extrusion and the print to stop.  There is a sweet spot.

--------------------
Chuck H
3D Printer Review Blog...
Posted : 26/06/2021 4:35 pm
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