Stepping Motor Overheating???

[solissydney (Ken)]

I did some maintenance on my scope to day, and with power on, I happened to touch the DEC stepping motor, not for long though, ouch.
The temperature of the motor was 38 degrees, 14 degrees above ambient.
Is this normal or abnormal?

[DavidU (Dave)]

Most smaller Stepper operating temperature range is -30C to 150C+
It sounds ok to me however we will see what a member says who has a similar setup

[[1ponders] (Paul)]

Being the Dec motor is should not be hot unless you are doing an awful lot of slewing seeing as the Dec motor doesn't drive unless you tell it to. Sounds to me like there is something not right there.

[solissydney (Ken)]

I should add that it is an Equatorial Mount, with the Dec motor seldom moving, unless auto guiding.

[Gama]

Steppers are always powered when on, and should get hot/warm (On hi tourque steppers). They are on, so the shaft position of the stepper is maintained.
A stepper moves by changing phase of the fields, not by applying a voltage.


Theo.

[Spanrz (Brett)]

heat = current flow through the stepper.

Either something is jammed up or the current is too high for the motor.
I've been through this. They should be warm to touch, but not overly warm.
If it's hotter than a cup of coffee (mug surface temp), you got problems.

[solissydney (Ken)]

Thank you for your input
I feel better now that I know it is ok for the stepping motor to be warm even though it is not working. It makes sense too.
Ken