Re: Stepper motor current question

At 14:49 26/09/2002 +0000, you wrote:

>GIVEN: PacSci 6410 driver and PacSci 2.8 A DC biplolor motor
>
>6410's DIP switch allows for motor current settings of:
>
>5.0
>4.375
>3.750
>3.125 ? ----+
> |
>2.5 ? ----+------obviously it should be one of these two --+
>1.875 |
>1.25 but
>0.625 |
> |
>I just don't know enough about the electronics involved to know which is
>the better choice. I think if you set the drive for 3.125A that's what
>you're going to GET and that's above the rating for the motor .... but ...
>is that a really big deal? will the motor run overly hot? could I damage
>it, etc. etc. On the other hand if I select the lower value at 2.5 does
>that under power, the motor or create other issues.

Ken -

Judging from past threads on this subject, I suspect the right answer is to
set it for 2.5A:

- Under-driving the motor by .3A will make little difference in the motor's
performance anyway;
- Running the motor over its rating runs the risk of overheating for little
(if any) performance gain
- As it is a microstepping drive, running at higher than rated current will
tend to cause "bunching" of the microsteps due to magnetic saturation
making the motor's performance less linear, so the motor will not run as
smoothly/accurately as it could.


Regards,
Tony