Re: [CAD_CAM_EDM_DRO] Re: isolation, current and velocity, encoders

jmw@... wrote:

> Assuming it's OK to put the encoder right on the screw (and you did,
> right--the SumTak's?)

Yes, with a helical-slitted coupling.

> maybe a fellow who knew what he was doing could
> rig non-contact optical tachs pointed at the motor shafts. Dan M. has
> kind of broken the price barrier on these things ...

The non-contact optical tach is for setting spindle speed on a variable
speed drive setup (like the treadmill motors). It doesn't give direction
information, only speed, and only updates a few times a second.

I have found a nice Escap DC motor at Herbach & Rademan that
makes a perfectly fine DC tach, for $7.95
Escap and Maxon make their tachs with the same internal design
as their smallest motors. I drove my tachs with a Berg toothed belt
with a fine steel cable inside. it works very well.

Jon