Stepper Motor running temperature range

I'm getting my printer up and running.

I have 5.1v 1.0a motors running on a 4 Axis TB6560 board with Mach3, PSU power supply.

Have motor drivers set to 50% current, on 25% current the motors barely have any holding torque.

I have tuned the motor drivers in Mach3 to where the motors run smoothly without jerking or missing steps.

I've been running pen plots to do tests and calibration, 2 hours or so on longest gcode program run. Have been running it fairly solidly for the past two days on tests.

I measured the x axis motor temperature close to 130 degrees celsius, and z and y motors at 100 celsius and up.

Driver and board components are cool to the touch. Driver board has not crashed or overheated.

Am I running too hot? I have heatsinks for the motors on order.

Edited 1 time(s). Last edit at 08/28/2012 08:31PM by Dirty Steve.

... you shouldn't heat the motors above 80 degree celsius or the wire isolation and rotor-magnetisation will degrade!

Try to reduce the motor current, so they will stay around 60 degree max. ...

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Going to try a different power supply with lower amps, currently using a 450w PSU rated at 25 amps.

... this would be the wrong way, as you need some 'reserves' in available current or your voltages would drop, when the motors hits the border!

Better reduce the motor current by adjusting it to a 'safe zone' with the trim-pot on the driver board ...

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Attached is a pic of the board I have. No pots, dip switches set to 50% on a 12V 25A supply. I dropped the motors down to 25% and there is barely any holding torque and steppers are jittery.

(from board documentation)
*Ampertage Selection:
Output current of the power supply can be calculated by the following expressions:
Output current = Rated current of your stepper motors * quantity + 2A
(For example, if you want to drive 3 * 2A Nema 23 stepper motors, theoretically 24V 8A DC power supply is recommended, but higher power such as 24V 10A/15A also will be good.

Would the 2 motor Z axis wired in parallel count as 1 or 2 motors? Motors are 5.1V 1A.

I calculate the required current to be 7A. I'm over 3 times the amp calculation on this PSU. WAY to many amps even with a little extra. Only going to run heated bed on the power supply, my hotend is 120v with a seperate power supply. Going to try a 10 amp supply.

I just hooked in a 1A (yes 1A) supply with only the motors hooked up, and it does run, with weak holding torque, motors are just a little warm to the touch after a code run.

Edited 1 time(s). Last edit at 08/29/2012 11:38AM by Dirty Steve.

... oh, this board ... best would be to search motors rated to 2 Amps or motor drivers that are better adjustable ...

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Was going by what they are using for a SeeMeCNC H1 printer. No complaints about the driver board that Ive run into yet.

Most smaller steppers are rated for about 80C much higher and you risk damage, on a reprap where you don't need a lot of holding torque you can run the motors with less than ideal current such that they are warm to the touch.
To me at least 130C is way too hot.

Switched out to a 15amp power supply, motors now running between 60 and 65 celsius.

You should run with the highest amperage power supply you can. A lower rating of power supply current has no impact on your circuit. The current rating of the power supply is only an indicator of how much it is ABLE to supply not how much it DOES supply. Your circuit will draw however much current it needs.

Your logic is like saying a lower horsepower car will make you drive slower. It's really unrelated to the problem at hand.

2 motors in parallel with split the current in half. So if your stepper driver is set to 2A and you have two motors in parallel then each one will draw roughly 1A.

If you ran the motors in series then both motors would get whatever current you set the stepper driver to.