Re: How to deal with Stepper Motor heat - 150 degrees F

Motor losses really only come from a few places, windings (I2R),
hysteresis, eddy currents, and bearing friction. The voltage at your
PWM driver isn't really relevent until you get to a couple hundred
volts where insulators break down and arcing is an issue.

So unfortunately, your only option is to reduce the current, which can
only be done with the chopper or PWM.

On 8/23/06, lcdpublishing <lcdpublishing@...> wrote:
> Hi guys,
>
> I ran a test the other day to see how hot the stepper motors are
> getting on my machine. After 30 minutes, they (3 of them) were all
> at 150 degrees F.
>
> The motors are 5 volt motors rated at 1.4 Amps, nema 17. I am
> driving them at 30 volts and 1.4 amps. The driver chip is the
> SLA7062M chip. This heat test was performed with the motors holding
> their position as that is the best way I know to "push them" for
> heat build up.
>
> I know I could get another transformer and drop the voltage, but
> would prefer to keep it at 30 volts for performance. I have a bit
> of room where I could add some chunks of aluminum for heat sinking,
> but not sure if that would get the temp down enough. I have no room
> for fans so I am sort of pondering what directions I can go to deal
> with this.
>
> As always, I am open to any and all suggestions or ideas.
>
> One interesting thing I heard from a very reliable source is that if
> I switch from the SLA7062M based driver to a Gecko driver, the motor
> heat would drop down significantly. However, I don't have the
> budget for 3 Geckos on this little machine.
>
> Chris