Z stepper overheating

Here we go!

The Z stepper on my machine is overheating really quick… after the crown test, one pass, i can’t bareely touch it… the X/Y seems hot as well but not as much as the Z one… any idea?

Mega2560/ramps/8825/dual end stop/marlin

did you set your driver voltages.

Yes, all at 0.7V…

That number depends on your steppers, 0.7 only works for very large nema 17’s.

So, I have to reduce the Volts using the pots?
Is there any rule of thumb to estimate what is required for my motors?

Vref is half the current motor setting in amps (Vref@0.7V means 1.4A of current) - which exceeds the rating of the motor in your picture which should be set to 0.6V or lower. Try to keep the current below the rated value of the motor unless you need 100% of the torque it can provide.

You can’t hurt the driver, it has thermal and current overload protection - but your stepper motor is another story.

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Dropped at 0.5V…still very hot after a 10minutes plotting job…should i drop it more, or is there something else I did wrong?

Generally the way I do it is to plug everything on, then engage the steppers, and turn the pot just until I can’t hear the buzzing sound of the motor anymore. Then I turn it back a tiny little tad and it’s usually just fine.

Just be careful not to turn it the wrong way and use a good insulated screwdriver, I happened sometimes to ruin the driver by not paying attention.

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0.6V is 100% of the steppers rating, typically that number is exaggerated and you never want to run a stepper at max power for continuous use. 80% is better, so 0.45V is more a better choice.


But you could also have bad drivers with an odd resistor value and our standard formula could be wrong, turn it down 0.05V per step until your steppers are just warmer than the room when running for more than 20Min.

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Had to drop to 0.350V (75%), problem sorted, no more overheating, stepper just warm, not HOT after 30 min plotting job!
Thanks all for your help!

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