Extruder motor temperature - insanely hot
 
Notifications
Clear all

Extruder motor temperature - insanely hot  

  RSS
MTJC
 MTJC
(@mtjc)
Trusted Member
Extruder motor temperature - insanely hot

I'm slightly worried about the temperature of the extruder motor on the (or at least with my) mk3. I understand that steppers can run quite hot and that the mk3's extruder stepper temp could be perfectly within operational range but this has to be the hottest running stepper motor I've ever experienced to the touch by far. I've owned perhaps a dozen or so printers and with each one, I've compared how hot the motors are between them with the "how long can I keep my finger on it" test. I know, not exactly the most objective test. That being said, what I've found over the years is that there's a surprisingly large range in operating temperature between the various printers stepper motors that I've owned. For instance, the zortrax m200 steppers run at practically room temperature whilst the flashforge finders steppers ran so hot that I could not keep my finger on them for more than 5 seconds at most. So clearly if I found one of the mk3's steppers running very hot, it would not be unique in this regard. Having said that, my mk3's extruder motor takes it to a whole other level, the hottest yet and by quite some margin. I can't keep my finger on the thing during a print job for more than 1-2 seconds at the very most before extreme pain from the heat transfer into my finger.

Anyone else surprised by how hot it runs and slightly worried too or it's just me? 😛

Napsal : 04/04/2018 6:28 pm
Kwaad2
(@kwaad2)
Honorable Member
Re: Extruder motor temperature - insanely hot

I just posted this last night.
THIS POST

I have a few questions.

1. What material are you printing? (PLA?)
2. What temp are you printing it? (Under 205c?)
3. How big of an object are you printing? (Is the printer actually printing high speed on the infill?)
4. How fast is the infill speed on your Slicer profile?

Hi, I'm Sean. I used to work on CNC machines.
I try to not make mistakes, but the decision is YOURS.
Please feel free to donate to my filament/maintance fund.

Napsal : 04/04/2018 6:49 pm
stoofer
(@stoofer)
Estimable Member
Re: Extruder motor temperature - insanely hot

Everyone thinks it's hot. It is hot.

Jo answered in one of (the many) earlier threads about this and said it's fine, the motor is rated to ... I don't know whatever temperature is significantly higher than "insanely hot"...

However some people are experiencing problems with heat soak (particularly in enclosures) causing filament to escape the printer. Some people have worked on fans blowing air into the gear area to help. Some have put heatsinks on the motor body.

Napsal : 04/04/2018 7:02 pm
MTJC
 MTJC
(@mtjc)
Trusted Member
Topic starter answered:
Re: Extruder motor temperature - insanely hot


I just posted this last night.
THIS POST

I have a few questions.

1. What material are you printing? (PLA?)
2. What temp are you printing it? (Under 205c?)
3. How big of an object are you printing? (Is the printer actually printing high speed on the infill?)
4. How fast is the infill speed on your Slicer profile?

1. PLA
2. Depends on the print job. It can vary from 200C up to 215C.
3. I print small and large objects and different speeds for different jobs with different requirements. Infill is usually no less than 100mm/s.
4. Typically no less than 100mm/s when using S3D, else the default 200mm/s if using Slic3r PE.

Napsal : 04/04/2018 7:06 pm
reid.b
(@reid-b)
Reputable Member
Re: Extruder motor temperature - insanely hot

I still think the instructions for extruder idler spring tension are wrong- this can lead to elevated stepper motor temps. There are several variables in construction that IMHO lead to variation in how much pressure is applied to the filament if you follow the manual.

I myself turn in the tension screws until I can feel the spring begin to resist movement (sometimes you have to turn it out and back in to feel this "contact" point with the spring.) I then turn the screw in 1/2 additional turn. No more, no less.

I run 80mm/s on infill, PLA at 205, and have no issues with motor temps.

Napsal : 04/04/2018 7:10 pm
MTJC
 MTJC
(@mtjc)
Trusted Member
Topic starter answered:
Re: Extruder motor temperature - insanely hot


Everyone thinks it's hot. It is hot.

Jo answered in one of (the many) earlier threads about this and said it's fine, the motor is rated to ... I don't know whatever temperature is significantly higher than "insanely hot"...

However some people are experiencing problems with heat soak (particularly in enclosures) causing filament to escape the printer. Some people have worked on fans blowing air into the gear area to help. Some have put heatsinks on the motor body.

Cool. I didn't know Jo had addressed concerns surrounding the observed high operating temp of the extruder stepper. Certainly provides a level of peace of mind. It's still insane how hot it runs. Should almost come with a "do not touch. risk of burning." warning label on it or something, lol.

Napsal : 04/04/2018 7:11 pm
Kwaad2
(@kwaad2)
Honorable Member
Re: Extruder motor temperature - insanely hot


Cool. I didn't know Jo had addressed concerns surrounding the observed high operating temp of the extruder stepper. Certainly provides a level of peace of mind. It's still insane how hot it runs. Should almost come with a "do not touch. risk of burning." warning label on it or something, lol.

The motor itself is fine up to about 110-120c. (plenty hot to boil water)

The issue people are having, and I think it is the SAME issue.

They are melting their PLA when the motor hits 80-90c. (which is TOTALLY safe for the motor!)

I found increasing the temp on the PLA by 5c (EDIT: 215c to 220c), dropped the temp of the motor, by around 5c.

I think you are knocking on the "edge of issues" with the temp melting the PLA. (I've never had the issue. I print small stuff, with thin layers, so low linear speed, and even slower extruder speeds)

As I said in my other post, I printed something for my wife last night, and the motor was TOASTY. Increased the PLA temp 5c, and the motor cooled WAY down. I think some Filaments are worse than others. I find the Prusa-Grey that came with the printer to be "Stiff" even @ 220c, compared to my cheap PLA at 205c.

I can not imagine the strain on the printer attempting to print it at 200c as listed on the spool, or worse 175-185 like I have seen people say they like to print PLA at. (Like, I would try it, but I'm not gonna TRY to break my printer!)

Hi, I'm Sean. I used to work on CNC machines.
I try to not make mistakes, but the decision is YOURS.
Please feel free to donate to my filament/maintance fund.

Napsal : 04/04/2018 7:20 pm
martin.m25
(@martin-m25)
Estimable Member
Re: Extruder motor temperature - insanely hot

Classical open loop steppers are current controlled, so motor temperature would be independent on mechanical load...

Anyone knows what features of the TMC2130 are used to get the apparent current dependency on load? Stallguard 2? Coolstep?

https://www.trinamic.com/products/integrated-circuits/details/tmc2130/
Looking at the code
https://github.com/prusa3d/Prusa-Firmware/blob/MK3/Firmware/tmc2130.cpp
both is mentioned, but at a quick glance I don't quite see what's going on. BTW I hate undocumented code.

- Martin

- Martin

Napsal : 04/04/2018 7:51 pm
MTJC
 MTJC
(@mtjc)
Trusted Member
Topic starter answered:
Re: Extruder motor temperature - insanely hot


Classical open loop steppers are current controlled, so motor temperature would be independent on mechanical load...

Yeah, I was about to say, I can't see why choice in print temperature would/should affect the extruder stepper motors operating temperature either. Also, touching the bondtech gears whilst printing, it's not remotely hot to the touch. Warm at best.

Napsal : 04/04/2018 8:50 pm
MTJC
 MTJC
(@mtjc)
Trusted Member
Topic starter answered:
Re: Extruder motor temperature - insanely hot


I still think the instructions for extruder idler spring tension are wrong- this can lead to elevated stepper motor temps. There are several variables in construction that IMHO lead to variation in how much pressure is applied to the filament if you follow the manual.

I myself turn in the tension screws until I can feel the spring begin to resist movement (sometimes you have to turn it out and back in to feel this "contact" point with the spring.) I then turn the screw in 1/2 additional turn. No more, no less.

I run 80mm/s on infill, PLA at 205, and have no issues with motor temps.

Interesting. Have you performed any tests to verify your hypothesis over increasing idler tension leading to significant/noticeable increases in extruder stepper motor operating temperature by any chance? I can't see why it would/should though.

Napsal : 04/04/2018 9:07 pm
martin.m25
(@martin-m25)
Estimable Member
Re: Extruder motor temperature - insanely hot


Interesting. Have you performed any tests to verify your hypothesis over increasing idler tension leading to significant/noticeable increases in extruder stepper motor operating temperature by any chance? I can't see why it would/should though.

The TMC2130 can detect motor load and adjust current accordingly. Not sure if/how this is used, but it would explain that increasing mechanical load (idler tension or lower hotend temperature) would increase motor current.

- Martin

- Martin

Napsal : 04/04/2018 9:31 pm
MTJC
 MTJC
(@mtjc)
Trusted Member
Topic starter answered:
Re: Extruder motor temperature - insanely hot


The TMC2130 can detect motor load and adjust current accordingly. Not sure if/how this is used, but it would explain that increasing mechanical load (idler tension or lower hotend temperature) would increase motor current.

- Martin

Oh good point. I misread sean's post. Ok, that theory makes sense to me now and I can see the plausibility of it (would be nice to get a confirmation by Prusa Research on this) but what about the idler tension? I still can't see how/why that would increase the mechanical load on the motor.

Napsal : 05/04/2018 12:36 am
Kwaad2
(@kwaad2)
Honorable Member
Re: Extruder motor temperature - insanely hot


Oh good point. I misread sean's post. Ok, that theory makes sense to me now and I can see the plausibility of it (would be nice to get a confirmation by Prusa Research on this) but what about the idler tension? I still can't see how/why that would increase the mechanical load on the motor.

😉

I don't see how the idler would make a big difference with any "hard" filament. I could see it EATING energy with a flex filament. (good luck with that.. :twisted:)

I understand it can make a difference, as the "tighter" it is, the deeper the bite, and the more "smoosh" it will do on the filament. But the real "energy sink" is RAMMING clay-like pastic through a 0.4mm hole.

But seriously, if you tightened your tension gears ALL the way in... and your extruder is trying to pinch the filament in half... it's hard to blame the printer for that. 😉 ... and it's an easy fix!

Hi, I'm Sean. I used to work on CNC machines.
I try to not make mistakes, but the decision is YOURS.
Please feel free to donate to my filament/maintance fund.

Napsal : 05/04/2018 10:11 am
Kameron
(@kameron)
Active Member
Re: Extruder motor temperature - insanely hot


I still think the instructions for extruder idler spring tension are wrong- this can lead to elevated stepper motor temps. There are several variables in construction that IMHO lead to variation in how much pressure is applied to the filament if you follow the manual.

I myself turn in the tension screws until I can feel the spring begin to resist movement (sometimes you have to turn it out and back in to feel this "contact" point with the spring.) I then turn the screw in 1/2 additional turn. No more, no less.

I run 80mm/s on infill, PLA at 205, and have no issues with motor temps.

I can't "feel" differences in temperature if the spring tension is very low or high (by following the instructions in the assembly manual). Can't let my fingers rest on the motor after some minutes of printing...

Napsal : 05/04/2018 11:31 am
shire
(@shire)
Active Member
Re: Extruder motor temperature - insanely hot

just read this and tested mine, the extruder motor is too hot to even touch, I am printing jobs at about an hour duration.
This is a factory assembled MK3 about 3 weeks old, not done too much printing, due to numerous issues.
Also clicking noises on infill sections, and often 'collision detected' on regular basis.
not a happy man

Napsal : 24/05/2018 9:24 pm
JoanTabb
(@joantabb)
Veteran Member Moderator
Re: Extruder motor temperature - insanely hot

Hi Terence,

Are you using firmware 3.2.1?

there have been some changes to drive current in recent firmware updates!

regards Joan

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK

Napsal : 24/05/2018 10:25 pm
Gato
 Gato
(@gato)
Reputable Member
Re: Extruder motor temperature - insanely hot

I also had to disable crash detection due to so many false alerts. Y belt tension is at 240 and cannot see another thing blocking or affecting the movement to trigger crash. Disabled feature and prints are now happy

Napsal : 25/05/2018 1:36 am
OrzelPiotr
(@orzelpiotr)
Eminent Member
Re: Extruder motor temperature - insanely hot

Problem may occur if extruder gears are not parallel to each other or they aren't in line of teflon tube.

Napsal : 20/07/2018 12:35 pm
helene.i
(@helene-i)
Active Member
Re: Extruder motor temperature - insanely hot

@sean.h8

Hi Sean, would you be able to clarify my understanding of your statement?

"As I said in my other post, I printed something for my wife last night, and the motor was TOASTY. Increased the PLA temp 5c, and the motor cooled WAY down."

Why does increasing the print temperature have the effect of reducing the temperature of the extruder motor?

Thank you.

Napsal : 14/08/2018 5:16 am
Share: