Re: [CAD_CAM_EDM_DRO] Re: digitizer arm, w/ encoder?

Alan Marconett KM6VV wrote:

> Dave, Ballendo and the list,
>
> I've been kicking around several sensors since the "center finder"
> thread of a few weeks ago (yes I have and can now use a center
> finder!). Strain gage, electrical contact, a "last word" connected to
> an encoder disk, and latest, the photo-interrupter. Rudy's "Shop
> Wisdom" book shows making a "dial indicator", an arm on a spring for
> mechanical advantage from tip movement. SO... with the extra travel
> (.5"?) of the "hand", I think the vane could cut the photo sw. fairly
> fast. It might be practical, single axis of travel.
>
> The mirror is a good idea! Let me think about that a little. 2 or 3
> directions, probably not with this design. The strain gage could
> probably give a couple of degrees of freedom. A clockwork gear
> advantage (like a dial indicator) could directly turn an encoder wheel,
> and would give mills of change. Lets see, can one even FIND a
> mechanical watch for some small gears? Must give more thought! Any
> clock makers out there?
>
> Alan

I see this as only being used on the Z axis...in fact what I had in mind was one of the $10 dial indicators. In Z only ,one could
edge trigger, either on the light hitting the detector or going off it. Resolution should be about a mil. Just attach the mirror to
the post driving the needle.

Dave

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