Re: [CAD_CAM_EDM_DRO] Renishaw, digitizers

>
> Alan Marconett KM6VV wrote:
>
> > Hi to the list,
> >
> > I just realized that I sent this directly to Doug, instead of the list.
> > I had another thought on the digitizer. What about just three balls,
> > equally spaced in an insulating ring. The "armature" would be a flat
> > disk, with three hemispherical cups, on the BOTTOM side of the disk,
> > arranged to register with the three balls. Slight pressure on top, with
> > a braided contact wire to ground. Long probe extends down through the
> > center. Now THAT I think I can easily machine (well, maybe the cups
> > would take some thought)!
>
> 3 conical depressions (like a countersink) would work as well, and might
> be a lot easier to make and be sure they were on target. In fact, you
> don't even need cones! 3 holes with well-chosen diameters so that they
> sat part way down on the balls would work quite well.
>
> Jon