Re: Re: Cheap Encoders

> From: Brad Heuver <bheuver@...>
> I've proposed the concept of taking an old
> trav-a-dial and using it to directly drive a rotary encoder. Kind of a
> new tech approach to the old way of doing things. It should work just
> fine, and give you the same accuracy the trav-a-dial had, with a better
> view of position. To my knowledge nobody has yet built such a beast,
> however.

Southwestern Industries, who make both the Trav-a-dial and Proto-Trak CNC
controls have done exactly this. In fact they have made a regular DRO like
this since the late '70s. I don't know if they sell the Trak sensors
separately, and if they do, they'll cost hundreds of dollars each. Some of
the folks I know who have used the Proto-Trak setup say that the wheels slip
when drenched with coolant, as is common with CNCs. Another objection to them
is that the pressure that they bear against the machine with causes
accelerated wear of the ways.

Matt