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What is the expected i3 mk3S extruder motor temperature?  

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GregB
(@gregb)
Trusted Member
What is the expected i3 mk3S extruder motor temperature?

Did a little basic maintenance on my extruder assembly last night.  I left the feeder restraining bolt (that's what I'm calling it) a little looser to make sure there wasn't too much pressure on the motor.  Had the expected Benchy failure at around 30%.  Stopped the print, freed the remnants of the derelict craft, and began another print.  Extrusion was still near zero at that point with immobile Bondtech gears and I used a meat thermometer to take a temperature reading:

41C

I suspect this was higher during the failed print and that's not exactly the correct tool for the job.  Previous posts stated that 50C was too high; is 41 what's expected during a normal print?  Anyone have an idea of what I'm doing wrong?

If motor overheating is the problem the PETG arriving today may not work either.  PLA at 190 up to 220 still gets stuck at 30% and forms the impacted/expanded head.

Posted : 17/05/2019 12:09 pm
Vojtěch
(@vojtech)
Honorable Member
RE: What is the expected i3 mk3S extruder motor temperature?

41 ​°C should be absolutely fine. The motor itself does work even at 90 °C, I tested that during an ABS print. The issue with a hot motor is that the gears will be just as hot, which doesn't make PLA happy. But if you're getting jammed filament at 41 °C motor temperature, it's probably not because the extruder gears are slipping on the softened filament.

What do you mean by 'immobile Bondtech gears'? That could be a clue ...

This post was modified 6 years ago by Vojtěch
Posted : 17/05/2019 12:48 pm
GregB
(@gregb)
Trusted Member
Topic starter answered:
RE: What is the expected i3 mk3S extruder motor temperature?
Posted by: Vojtěch

41 ​°C should be absolutely fine. The motor itself does work even at 90 °C, I tested that during an ABS print. The issue with a hot motor is that the gears will be just as hot, which doesn't make PLA happy. But if you're getting jammed filament at 41 °C motor temperature, it's probably not because the extruder gears are slipping on the softened filament.

What do you mean by 'immobile Bondtech gears'? That could be a clue ...

The gears don't move at all after a certain point.  Well, technically the one drive gear is inside and I can't see it but there's no evidence of movement.  After the slipping and clicking begins, it's only a short time before nothing moves at all, to include the freely rotating gear visible from the outside.

I may have mentioned this in another thread, but a nozzle change resulted in a mostly complete but sloppy Benchy.  What may have helped that time is that I didn't make it pull the filament from the spool but let it freely hang.  That was just once, however, and freely hanging filament hasn't had an effect on subsequent prints.

This post was modified 6 years ago 2 times by GregB
Posted : 17/05/2019 12:56 pm
Vojtěch
(@vojtech)
Honorable Member
RE: What is the expected i3 mk3S extruder motor temperature?

Does the motor turn at that point? You can see that by looking at the axle in the center of the motor - possibly making it more visible by putting a dot or line with a sharpie pen on it.  You may have mentioned it somewhere in the other thread, too I guess, but I don't see it there.

Posted : 17/05/2019 1:57 pm
GregB
(@gregb)
Trusted Member
Topic starter answered:
RE: What is the expected i3 mk3S extruder motor temperature?
Posted by: Vojtěch

Does the motor turn at that point? You can see that by looking at the axle in the center of the motor - possibly making it more visible by putting a dot or line with a sharpie pen on it.  You may have mentioned it somewhere in the other thread, too I guess, but I don't see it there.

I haven't looked for that but should have thought of it.  Every observed indicator indicates that the motor just stops at a certain point.  I'll look for it when I run the new filament through it tonight.  If the new stuff works I'll start a new thread.  Hopefully the SD card designs print with other materials.  It's stubborn about reverting to preloaded settings.

 

Oh, and thank you for all of your help.

Posted : 17/05/2019 2:34 pm
Vojtěch
(@vojtech)
Honorable Member
RE: What is the expected i3 mk3S extruder motor temperature?

Good luck with PETG!

Posted : 17/05/2019 2:53 pm
Vojtěch
(@vojtech)
Honorable Member
RE: What is the expected i3 mk3S extruder motor temperature?
Posted by: gregory.b10

  Every observed indicator indicates that the motor just stops at a certain point. 

If there was a filament jam anywhere or filament overheat, then there would be clicking, lost steps or slipping teeth on the hobbed gears. Sounds. If there is nothing and the motor 'just stops', then it's likely not a jam.

If the motor would spin and the gears wouldn't, then it'd be the set screws that get loose after heating up.

If the motor just gives up spinning, it could be the stepper controller on the Einsy board overheating (but the firmware would normally report that), or a broken cable to the motor that loses contact between the interrupted strands of coppper when above a certain Z height. The last problem can be checked by trying Settings->Move Axis->E at different Z heights.

This post was modified 6 years ago by Vojtěch
Posted : 17/05/2019 2:59 pm
GregB liked
GregB
(@gregb)
Trusted Member
Topic starter answered:
RE: What is the expected i3 mk3S extruder motor temperature?
Posted by: Vojtěch
Posted by: gregory.b10

  Every observed indicator indicates that the motor just stops at a certain point. 

If there was a filament jam anywhere or filament overheat, then there would be clicking, lost steps or slipping teeth on the hobbed gears. Sounds. If there is nothing and the motor 'just stops', then it's likely not a jam.

 

I's both: Clicking then stoppage.  It won't resume again until after the distorted filament is removed.  My theory is that for some reason pressure builds up in the nozzle, creates the swelling mentioned earlier, and the motor can't push the expanded/compacted filament to where it needs to go.

I don't want to say it's bad filament as it's what came with the machine.

Attachment removed
Posted : 17/05/2019 5:17 pm
--
 --
(@)
Illustrious Member
RE: What is the expected i3 mk3S extruder motor temperature?

There is a known issue with firmware overheating the TMC controller into shutdown conditions.  Try moving to 3.7.1 firmware.

My extruder runs at 50c, routinely, and I have seem 55c on busy prints.  I have NEVER had any issues with filament jams related to the shaft softening filament in the gear teeth.  

 

PS: that last pic looks similar to what I was removing when experiencing heat break jams.

This post was modified 6 years ago 2 times by --
Posted : 17/05/2019 5:37 pm
GregB liked
GregB
(@gregb)
Trusted Member
Topic starter answered:
RE: What is the expected i3 mk3S extruder motor temperature?
Posted by: Tim

There is a known issue with firmware overheating the TMC controller into shutdown conditions.  Try moving to 3.7.1 firmware.

My extruder runs at 50c, routinely, and I have seem 55c on busy prints.  I have NEVER had any issues with filament jams related to the shaft softening filament in the gear teeth.  

 

PS: that last pic looks similar to what I was removing when experiencing heat break jams.

Thanks.  I remember you posting about this in another thread and I appreciate it.  I don't remember anything about the firmware version but I'll look into it tonight.  

So, 13 May update.  Thanks!  I guess I get to have some fun figuring that out tonight: https://manual.prusa3d.com/Guide/Upgrading+the+firmware+v1.5/66#_ga=2.12267004.932775015.1558112011-2076873615.1552326685

Posted : 17/05/2019 5:52 pm
bobstro
(@bobstro)
Illustrious Member
RE: What is the expected i3 mk3S extruder motor temperature?
Posted by: gregory.b10
The gears don't move at all after a certain point.  Well, technically the one drive gear is inside and I can't see it but there's no evidence of movement.  After the slipping and clicking begins, it's only a short time before nothing moves at all, to include the freely rotating gear visible from the outside.
Wait, are you referring to the Bondtech extruder gears? There is a common issue with the axle of the idler wheel in the door working loose and causing intermittent jams, clicks and skips. Have you check to verify that gear is secure and doesn't flex when pressed? It's usually a matter of re-seating the axle, although there are a variety of improvements to the actual door available for printing.
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Posted : 17/05/2019 7:42 pm
GregB
(@gregb)
Trusted Member
Topic starter answered:
RE: What is the expected i3 mk3S extruder motor temperature?
Posted by: bobstro
Posted by: gregory.b10
The gears don't move at all after a certain point.  Well, technically the one drive gear is inside and I can't see it but there's no evidence of movement.  After the slipping and clicking begins, it's only a short time before nothing moves at all, to include the freely rotating gear visible from the outside.
Wait, are you referring to the Bondtech extruder gears? There is a common issue with the axle of the idler wheel in the door working loose and causing intermittent jams, clicks and skips. Have you check to verify that gear is secure and doesn't flex when pressed? It's usually a matter of re-seating the axle, although there are a variety of improvements to the actual door available for printing.

Yes, the bondtech gears.  I've had the door open a couple times and verified it's freely moving.  Will check again though!

 

Posted : 17/05/2019 8:01 pm
GregB
(@gregb)
Trusted Member
Topic starter answered:
RE: What is the expected i3 mk3S extruder motor temperature?
Posted by: gregory.b10
Posted by: bobstro
Posted by: gregory.b10
The gears don't move at all after a certain point.  Well, technically the one drive gear is inside and I can't see it but there's no evidence of movement.  After the slipping and clicking begins, it's only a short time before nothing moves at all, to include the freely rotating gear visible from the outside.
Wait, are you referring to the Bondtech extruder gears? There is a common issue with the axle of the idler wheel in the door working loose and causing intermittent jams, clicks and skips. Have you check to verify that gear is secure and doesn't flex when pressed? It's usually a matter of re-seating the axle, although there are a variety of improvements to the actual door available for printing.

Yes, the bondtech gears.  I've had the door open a couple times and verified it's freely moving.  Will check again though!

 

Updated firmware, confirmed version, no indications of flex and still failure at around 30%.

The motor shaft is turning but difficult to see when it's moving back and fourth so much.  

Posted : 18/05/2019 11:18 am
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