steppers crosslinked?

At 11:51 AM 3/25/02 -0500, you wrote:

>diodes in the output stage, then all bets are off as
>to what will happen to the driver. The application notes
>for the L298 show how to use diodes.

These are commercial drivers from Microkinetics.

>As a guess to what is happening, the motor you are
>turning is generating power that is effectively
>rectified and fed back into the power supply and thus
>to the other drive.

I figured that much out myself. This only happens between the 'a' and 'b'
axes. Nothing between any other pair. I had a blown chip in 'b' driver. Am
not sure this phenom was happening before I fixed that. Anything else in
that driver that could be causing this?

>manual controls, I suggest that you provide an
>electrical disconnect between the motors and the
>drivers while running manually.

I'm hip to that but there seems to be some question about what a
hypothetical fault can do when I'm under power too. Afterall, a pulse
linking two steppers implies a connection that shouldn't be there, and also
I may be having some problems with single steps on b axis anyhow; it seems
as if the activation of 'a' stepper may be backing me up a step on 'b'
during powered ops. At least I've been having some trouble hitting final
pass settings on 'b' in sizes of a few steps, which I set just before
activation of 'a' axis for the final pass itself.

Regards, Hoyt

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