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MK3 doesn't stop extruding  

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tyler.h8
(@tyler-h8)
Eminent Member
MK3 doesn't stop extruding

Before startinga print, where it prints that line in front of you, as the print head lifts up, filament continues to ooze out, about 3inches worth.

 

I've noticed failed prints due to what I thought were retraction settings. This seems more hardware related now.

 

All stock settings, printing PLA. Almost seems like the mechanism to retract the filament before it moves isn't working?

 

No noises. Layer height is good.

 

Posted : 24/10/2020 1:15 am
Dingo_aus
(@dingo-aus)
Active Member
RE: MK3 doesn't stop extruding

I have had that happen on one or two gcode files. For me the head went to the right more than it should and in a zig-zag.

When I re-sliced the problem went away.

This was on the n-1 version of firmware.

Gcode can alter the behaviour of the heat up sequence. i.e. you can change the temp when the PINDA height measurements are taken etc. So unless there is another indication of a hardware issue, I would start debugging the issue as a software one.

Does the problem exist on the standard Prusa models that come shipped on the SD Card for example.

 

Posted : 24/10/2020 2:35 am
tyler.h8
(@tyler-h8)
Eminent Member
Topic starter answered:
RE: MK3 doesn't stop extruding
Posted by: @nigel-hungerfordsymes

I have had that happen on one or two gcode files. For me the head went to the right more than it should and in a zig-zag.

When I re-sliced the problem went away.

This was on the n-1 version of firmware.

Gcode can alter the behaviour of the heat up sequence. i.e. you can change the temp when the PINDA height measurements are taken etc. So unless there is another indication of a hardware issue, I would start debugging the issue as a software one.

Does the problem exist on the standard Prusa models that come shipped on the SD Card for example.

 

It's happening on any model I print, and also on the prusa layer calibration, ruling out a slicing issue

I'm actually suspecting something is partially clogged, and building excess pressure

Posted : 24/10/2020 2:37 am
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(@)
Illustrious Member
RE: MK3 doesn't stop extruding

If the ooze / stringing is between the purge line and the skirt, that's pretty normal when filament is damp.  But a continuous extrusion of 0.4mm material during the move is something else. Inadequate tension on the Bondtech idler would be my first guess.

Posted : 24/10/2020 2:54 am
JPLau001
(@jplau001)
Eminent Member
RE: MK3 doesn't stop extruding
  1. Are you using the latest non-alpha release PrusaSlicer? If so check for the latest standard configuration updates via the "Configuration"- "Check for updates" menu item.
  2. Do you have the correct Manufacture's filament selected?  
  3. Are you using the correct Prusa printer configuration for your printer including the hotend nozzle size?
  4. Have you overridden any of the Prusa supplied default profiles, initial gcode sequences, or other PrusaSlicer settings. If you need to modify a supplied profile save it under a new descriptive name so you know why it exists later!
  5. Do you need to "dry" you printer filament? 
  6. Check that you're using the latest firmware for your specific printer from https://www.prusa3d.com/drivers/.

    If you've updated the printer firmware then you should reset your printer to the new firmware defaults and save those back to the printer's eeprom before rerunning the printer calibration again and reapplying any of your reviewed custom settings.

    Remember that there are separate different firmware zip files each of the following different Prusa I3 printer setups:

  • Prusa I3 MK3 
  • Prusa I3 MK3S
  • Prusa I3 MK3 with a MMU2
  • Prusa I3 MK3S with a MMU2S

 

Posted : 25/10/2020 9:05 am
tyler.h8
(@tyler-h8)
Eminent Member
Topic starter answered:
RE: MK3 doesn't stop extruding
Posted by: @jonathan-lin
  1. Are you using the latest non-alpha release PrusaSlicer? If so check for the latest standard configuration updates via the "Configuration"- "Check for updates" menu item.
  2. Do you have the correct Manufacture's filament selected?  
  3. Are you using the correct Prusa printer configuration for your printer including the hotend nozzle size?
  4. Have you overridden any of the Prusa supplied default profiles, initial gcode sequences, or other PrusaSlicer settings. If you need to modify a supplied profile save it under a new descriptive name so you know why it exists later!
  5. Do you need to "dry" you printer filament? 
  6. Check that you're using the latest firmware for your specific printer from https://www.prusa3d.com/drivers/.

    If you've updated the printer firmware then you should reset your printer to the new firmware defaults and save those back to the printer's eeprom before rerunning the printer calibration again and reapplying any of your reviewed custom settings.

    Remember that there are separate different firmware zip files each of the following different Prusa I3 printer setups:

  • Prusa I3 MK3 
  • Prusa I3 MK3S
  • Prusa I3 MK3 with a MMU2
  • Prusa I3 MK3S with a MMU2S

 

Latest MK3 firmware and default slicer settings. I'm going to do a cold pull with some cleaning filament.

I recall a similar issue when I went from petg to pla before.

If that doesn't work, I'll disassemble the extruder assembly and go from there.

Posted : 25/10/2020 2:22 pm
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(@)
Illustrious Member
RE: MK3 doesn't stop extruding

When you say "default" - we really don't know what you mean. Save project that has this issue as a .3mf file, wrap it in a ZIP archive and post the project here. We can then look at the part, the slice, and even the gcode.  Anything less and we'll be guessing. 

Posted : 25/10/2020 4:33 pm
tyler.h8
(@tyler-h8)
Eminent Member
Topic starter answered:
RE: MK3 doesn't stop extruding
Posted by: @tim-m30

When you say "default" - we really don't know what you mean. Save project that has this issue as a .3mf file, wrap it in a ZIP archive and post the project here. We can then look at the part, the slice, and even the gcode.  Anything less and we'll be guessing. 

It's not a slicer issue. The built in bed level calibration gives me issues too. When fast traveling from the initial line extrude, to the start of the calibration, filament seems to continue to come out. Not just a little ooze, but a pretty substantial amount.

Posted : 25/10/2020 4:37 pm
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(@)
Illustrious Member
RE: MK3 doesn't stop extruding

No photos, no projects; not sure how we can help then.

Posted : 25/10/2020 4:39 pm
tyler.h8
(@tyler-h8)
Eminent Member
Topic starter answered:
RE: MK3 doesn't stop extruding

@tim-m30

Couldn't upload on here, kept getting HTTP error. Video Below.

First Layer Calibration

Used 205C to try to prevent oozing

Does the same at 215C

Hatchbox PLA Wood (Does the same for other PLA)

I clean the nozzle off beforehand

Updated to MK3 3.9.1 firmware

 

A concerning amount of filament comes out when making that move.

This post was modified 12 months ago 2 times by tyler.h8
Posted : 25/10/2020 8:17 pm
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(@)
Illustrious Member
RE: MK3 doesn't stop extruding

Wood filament absorbs huge amounts of moisture and must be dried before printing.  Here's an example of a recent print I did. Wood filament loves water ... I should have dried it before printing, but was in a hurry. 

This post was modified 12 months ago by --
Posted : 26/10/2020 12:14 am
tyler.h8
(@tyler-h8)
Eminent Member
Topic starter answered:
RE: MK3 doesn't stop extruding
Posted by: @tim-m30

Wood filament absorbs huge amounts of moisture and must be dried before printing. 

This happens with other pla filament as well. Even dried some other pla

Posted : 26/10/2020 12:15 am
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(@)
Illustrious Member
RE: MK3 doesn't stop extruding

Wood will do this, period.  If you think normal dry PLA does this, then it is back to your gcode and settings. Which, you haven't given. So it's impossible to really help.

Posted : 26/10/2020 12:19 am
tyler.h8
(@tyler-h8)
Eminent Member
Topic starter answered:
RE: MK3 doesn't stop extruding
Posted by: @tim-m30

Wood will do this, period.  If you think normal dry PLA does this, then it is back to your gcode and settings. Which, you haven't given. So it's impossible to really help.

There is no settings to adjust!

This is the FIRST LAYER CALIBRATION.

I'll take apart the extruder and see if it's clogged or something.

Posted : 26/10/2020 12:21 am
JPLau001
(@jplau001)
Eminent Member
RE: MK3 doesn't stop extruding

@tim-m30

Latest MK3 firmware and default slicer settings. I'm going to do a cold pull with some cleaning filament.

I recall a similar issue when I went from petg to pla before.

If that doesn't work, I'll disassemble the extruder assembly and go from there.

ok. Given that extra information, when you change filament type between plastics with different melting points you need to

  1. preheat the hotend to at or above the temperature for the higher melting point plastic before inserting the new filament
  2. run the new filament thru the extruder at that tempurature until only the new filament is extruded a the other end
  3. then if the new filament melting point is at a lower temperature, reduce the hotend temperature to match that of the new filament while still extruding the filament so any "overbaked" new filament is removed from the hotend.

Never leave the filament just baking in the hotend.

Hope that the above helps prevent future blocked hotend issues

Posted : 26/10/2020 6:07 am
tyler.h8
(@tyler-h8)
Eminent Member
Topic starter answered:
RE: MK3 doesn't stop extruding

@tim-m30

I'm going to take a step back and verify if this is a situation where I have moisture in my filament.

Unfortunately my oven only goes down to about 175F, too hot to dry out filament.

Might be picking up a food dehydrator, and I'll dry out my filament and report back. Might take a week for me to get one.

I do use a drybox, but I haven't been keeping up with it.

Posted : 27/10/2020 11:19 am
tyler.h8
(@tyler-h8)
Eminent Member
Topic starter answered:
RE: MK3 doesn't stop extruding

Update

Got my dehydrater, 6hrs of drying, and I can print stuff again.

That wood filament still oozes a bit, but it's at least manageable now.

The normal PLA also prints better now too.

Posted : 31/10/2020 2:41 pm
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