Re: [CAD_CAM_EDM_DRO] MPGs

Michael Moore wrote:

>Does anyone in the aftermarket offer a good quality MPG that will work with most any CNC
>equipment? A lot of the MPGs I see offered with control upgrades seem to be in the $300-600
>range. I'm not terribly clear on what is inside one of them, but that seems like a lot for what
>appears to be a pretty simple device.
>
>

It has a low-resolution encoder, possibly with mechanical or magnetic
detents. A 25 cycle/rev
encoder will give 100 enocder counts when a quadrature encoder counter
decodes all
transitions.

>Every now and then there will be a used Fanuc MPG on eBay. Are MPGs sufficiently generic that
>they can be swapped between controls, or do they need to be designed specifically for each
>control?
>
>

Yes, most of them will be simple optical shaft encoders, although some
of the more exotic
control manufacturers might use something like a resolver to tolerate
the horrible shop
environments.

Jon