Re: Reduction Ratios

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "caudlet" <thom@t...> wrote:

> Now throw in the
> 3:1 ratio you need to run you motor in its range and you end up with
> 120,000 pulses per second.....
>
> As you can see the high line count servo encoders create some
> problems. This is where design tradeoffs occur. Do you change out

the

> encoders, direct couple the ballscrews, go with a step multiplier or
> find a controller that can do 120,000 pulses per second? [ this

space

> left open for Fred to jump in]
>
> Just be aware that designing a servo system is a set of actions and
> interactions and changing any part of the equation will change the
> answer!

I noticed that!

The DeskCNC controller, of course hums along at 125,000 steps per
second which is more than adequate for a system that needs 120,000.

Our SV-500 servo driver boards (5 amp, 30 volts) also have a 1x jumper
that permits the input rate to the driver to run at the slot count
instead of the quadrature count. This allows them to run smoothly at
high speed even with a slower parallel port controller.

Fred Smith - IMService
http://www.cadcamcadcam.com/hobby