Notifications
Clear all

[Closed] CONSTANT Extruder Jam  

  RSS
1humshark
(@1humshark)
Active Member
CONSTANT Extruder Jam

We received our first printer, assembled and have been printing for a week straight, until yesterday.  I started hearing the 'click,click' of the feed gears in the extruder assembly and realized that the TPU filament was stuck.  I managed to get the print to work but had to really go high on the print temps to get it done.

Today, I go back to PETg prints and can't for the life of me get anything to work.  Filament loads and then as it begins to print clicks away and under-extrudes leaving a residue on the build plate ( textured surface ) that is near impossible to remove.

So - I cool it down - then heat it up and pull the cord a couple of times, and all looks good.  I raise the temps and take a fine brass brush to the head and then clean the nozzle with the supplied pin.  ( all is clean and well ) 

Load up a fresh batch of filament and same thing.

This time i recalibrate everything - and it's all good, load filament again - no clicking while loading and extrusion of the filament comes through and down like normal.

Go to print a simple PLA test print from the PRUSA supplied library - and same thing - underextrusion with the dreaded clicking.....  gears look clean - and it loads fine... 

Someone else get this issue?  ( The print sheet is a mess and nearly impossible to clean completely ) 

Posted : 07/01/2020 4:04 am
bobstro
(@bobstro)
Illustrious Member
RE: CONSTANT Extruder Jam

If you're getting a near-impossible-to-remove smear of filament on the 1st layer, that means your Live-Z is way too close. Read up on Jeff Jordan's "Life Adjust" Live-Z calibration procedureas it is much easier to use and understand.

Read up on doing cold pulls. This will be important any time you switch from higher-temp filament (e.g. PETG) to lower-temp filament (e.g. PLA). If any bits of the higher temp material is left behind in the hotend or nozzle, it will not melt and extrude out when you start printing with the lower temp stuff, so you get a partial clog which can lead to the extruder clicking. You might also check the extruder tension screw(s) to ensure it's not under- or over-tight.

My notes and disclaimers on 3D printing and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan...
Posted : 07/01/2020 4:40 am
vintagepc
(@vintagepc)
RE: CONSTANT Extruder Jam
Posted by: @bobstro

Read up on doing cold pulls. This will be important any time you switch from higher-temp filament (e.g. PETG) to lower-temp filament (e.g. PLA). If any bits of the higher temp material is left behind in the hotend or nozzle, it will not melt and extrude out when you start printing with the lower temp stuff, so you get a partial clog which can lead to the extruder clicking. You might also check the extruder tension screw(s) to ensure it's not under- or over-tight.

Definitely this. For some reason, blends of PLA/PETG or PETG/ABS stick like the dickens, and are damn near impossible to remove, despite each one separately coming off incredibly easily when the sheet is cold. My powder-coated sheet got its first battle scar that way... there's still an outline of the thinnest layer of ABS/PETG mix that hasn't come off yet despite numerous prints over the same location.

 

Posted : 07/01/2020 2:23 pm
1humshark
(@1humshark)
Active Member
Topic starter answered:
RE: CONSTANT Extruder Jam
Posted by: @vintagepc
Posted by: @bobstro

Read up on doing cold pulls. This will be important any time you switch from higher-temp filament (e.g. PETG) to lower-temp filament (e.g. PLA). If any bits of the higher temp material is left behind in the hotend or nozzle, it will not melt and extrude out when you start printing with the lower temp stuff, so you get a partial clog which can lead to the extruder clicking. You might also check the extruder tension screw(s) to ensure it's not under- or over-tight.

Definitely this. For some reason, blends of PLA/PETG or PETG/ABS stick like the dickens, and are damn near impossible to remove, despite each one separately coming off incredibly easily when the sheet is cold. My powder-coated sheet got its first battle scar that way... there's still an outline of the thinnest layer of ABS/PETG mix that hasn't come off yet despite numerous prints over the same location.

 

 

Posted : 08/01/2020 3:27 pm
1humshark
(@1humshark)
Active Member
Topic starter answered:
RE: CONSTANT Extruder Jam

I'm not sure what's happening with my reply's either...  "I'm broken all over "

OK - did lots of cold pulls - and all is clean - 

After pulling PLA - I reloaded and started a calibration square ( live z) and immediately it begins to click and underextrude.

I JUST loaded and ran filament through without a problem ( hit no when it asks if color is correct  - and it can pull / push filament all day without clicking / jamming ) 

I am so confused...

Posted : 08/01/2020 3:37 pm
1humshark
(@1humshark)
Active Member
Topic starter answered:
RE: CONSTANT Extruder Jam

@bobstro

OK - YOU ARE THE WINNER

I went back and read all of these and this made sense.  My live adjust Z values have been running consistently around -1.275.

I started a square and this time decided to start with live z at -.8 and all is working.  I'll go over the unit and run a re-calibration when the square is done.  ( not sure why live z values would have jumped so ) 

Posted : 08/01/2020 3:50 pm
Share: