Extruder stepper motor temperature?

Good day all

I just finished a 5 hour print on my prusa i3. My Z motors are ambient, Y and X is just above ambient, but my extruder motor are a bit hot. I`m about 20 years into the rc hobby and was forced a few years back to get a $250 temperature gun which are spot on, on accuracy. If I spot check the extruder motor, it`s between 50 and 52 degrees celcuis. Too hot?

Nope. Typical. The extruder is working hard continuously throughout the print. You usually need to run the motor close to rated current to get sufficient torque to do the job. Running near rated current gets you near rated temperature rise. If you're concerned about it you could try turning down the current a little at a time and see when the extruder stops working properly, then bump the current back up a bit. Cutting the current in half drops the power 75% (torque, too, I believe).

Some people actually put heatsinks/fans on their motors.

Heat generated in motor and heat from hotend
contributes to high temperature

Put a small CPU cooler on it.

My SeeMeCNC - E3d extruder motor on Ordbot hardon got very hot on long runs
the 12v fan running continuously and finned aluminum cooled it nicely

First things first: start by tuning your stepper driver so that you provide to the motor only the power it needs.
No more. Because more power than needed means more current, thus more temperature.


Currently, I'm having a direct drive extruder pushing through a bowden tube, nema 17, and it's running great.
Around 40degrees.
And, if my direct drive can do it, any other extruder (AKA geared) can do it.

Cooler is solving an effect, try to tune the cause first.

good luck

my stepper motor for my extruder runs quite warm, so I added a fan. It is a stepper motor from a consumer grade flatbed scanner though. nice and lightweight and the gear reduction that came with it makes it very strong. the whole extruder assembly weighs less than the nema17 motor alone that was on the old assembly.

Hello iamdarkyoshi

Your extruder stepper should not run "quite warm"

I'm having my Delta printer working for 3 hours, a bowden extruder that's 50cm long and the motor temperature is preciselly 36C.
Also, I'm currently extruding ABS at 240C.

The motor is KH42KM2R001D
3.57V
7a (??)

maybe your stepper motor is to small



Indeed, if you have the extruder stepper on the carriage, the lighter the better.
This is the reason why mainly gear extruders are used.

However, you need to have similar weight/ inertia on both axes.
If you have a heavy bed on Y axis, it makes no sense to have a lightweight carriage on X...
I's not gonna speed up the whole printing...

There's no need to try to match the masses of the extruder carriage and the bed. In general you want to keep moving masses as low as possible because the motors will do a better job of controlling the motion and that will translate to better print quality. Whichever axis has the greater mass will limit the maximum print speed/acceleration of the machine, assuming equal torque motors on both axes, and assuming the extruder can keep up.

KH42KM2R001D is a 1.7A motor.

Edited 1 time(s). Last edit at 04/19/2015 08:25AM by the_digital_dentist.

Quote
alexella
Your extruder stepper should not run "quite warm"

I'm having my Delta printer working for 3 hours, a bowden extruder that's 50cm long and the motor temperature is preciselly 36C.

Your motor's operation on your printer does not necessarily indicate what other's may experience. Steppers are usually rated to operate with a 40-60 deg C temperature rise if not more. So even at the low end, they can operate quite warm to the touch with no issues. "Quite warm" also isn't a very scientific measurement. How exactly warm is "quite warm"?

Quote
the_digital_dentist
There's no need to try to match the masses of the extruder carriage and the bed. In general you want to keep moving masses as low as possible because the motors will do a better job of controlling the motion and that will translate to better print quality. Whichever axis has the greater mass will limit the maximum print speed/acceleration of the machine, assuming equal torque motors on both axes, and assuming the extruder can keep up.

KH42KM2R001D is a 1.7A motor.

I haven't conducted on this topic, it's just my educated quess that I'd rather reduce the mass of the moving axes in a balanced way.
As an extreme example, if my Y (the bed platform) has 1kg and if my Y (the carriage) has 200g...mh.... I'll do serious efforts to lighten up the platform.

Otherwise, totally agree with you: ideal case, moving masses should be feather light, thus ensuring minimum inertia and better print quality.
Probably in the future of 1m/sec printing speeds, this will be an absolute must.

Quote
cdru

Quote
alexella
Your extruder stepper should not run "quite warm"

I'm having my Delta printer working for 3 hours, a bowden extruder that's 50cm long and the motor temperature is preciselly 36C.

Your motor's operation on your printer does not necessarily indicate what other's may experience. Steppers are usually rated to operate with a 40-60 deg C temperature rise if not more. So even at the low end, they can operate quite warm to the touch with no issues. "Quite warm" also isn't a very scientific measurement. How exactly warm is "quite warm"?

Indeed, "quite warm" is subjective.
I expect something between 40 to 50C.
Indeed, stepper should work fine in the range of 50C-60C, or as specified by the manufacturer.
All I know is that the more I increase the temperature, the more I risk demagnetization.
On my rc cars, I experienced this first hand. But there, the temperature exceeded "quite warm" :-)
It was "skin burn" warm....


I've researched this topic when I wanted a closed enclosure with 60C-70C inside and... I decided it's to much for my motors.
Allthough... they might resisted for a couple of hundreds of hours, which is more than enough... I guess....

Quote
alexella
All I know is that the more I increase the temperature, the more I risk demagnetization.

This is true, but steppers rarely have any magnets inside...
I´d take a close look for stepper current, because of the stepper drivers. They are the weakest part in the chain IMHO
Olaf

Quote
o_lampe

This is true, but steppers rarely have any magnets inside...
I´d take a close look for stepper current, because of the stepper drivers. They are the weakest part in the chain IMHO
Olaf

I think....you are making a confusion between Stepper Motor and Induction Motor.
Stepper Motor has a lot of magnets, a looooot of magnets.

As for the stepper drivers, if proper ventilation is used, they should be fine.
Till now, I didn't burn any stepper.