Re: Testing Step Motors

> From: "Harrison, Doug" <dharrison@...>
> I recently purchased a Microkinetics Driverack system. Not too happy with
> it, but that's another story. I did, however, learn from first hand
> experience that microstepping has significant advantages over conventional
> halfstepping when using large (Nema 42) motors. With the old L/R drive
> amplifiers, such as were found on the BOSS 5 Bridgeport mills, resonance

was

> annoying but tolerable. But the newer switching amplifiers are so harsh
> that these large motors are almost unusable. Microstepping virtually
> eliminates the vibration. Having started with halfstepping and later paid
> for the upgrade I can vouch for the advantages.
>
> Accuracy is not so much an issue as is repeatability. Halfstepping a 400
> cog motor with 1:2 gearing yields .0005 resolution on a knee mill and

that's

> well within the repeatability of most low end machines. Repeatability
> becomes and issue when vibration is so bad the motor skips steps, and that
> is usually why they skip if we are assuming they were of adequate size to
> begin with.

I have recently completed a similar project retrofitting a BOSS machine with
Microkinetics DR8010 drives and keeping the original motors. I had hideous
problems just as you describe, and I was going to upgrade to the
microstepping version of the drive. Then I found, through experimentation,
that it was a software configuration problem.

What software are you using?

Matt