Re: [CAD_CAM_EDM_DRO] Lighted edge finder

Anne Ogborn wrote:

> I "hand CNC'ed" a complex lathe shape once by
> machining a guide out (+ 1/4" ) of aluminum,
> clamping this to the toolpost slide, and
> mounting a 1/2" dia. piece of drill rod to the bed in an
> insulated mounting. - I hooked a VOM on ohms scale to
> the "contacts", and hand fed the tool in until the scale kicked.

WOW! Brilliant!

I made an ellipsoidal mirror once by manual NC. I printed out a
table of numbers that represented the numbers I'd see on the lathe
handwheel dials every .010" along the axis of rotation. Then, I sat
there and turned the cranks following down the table. I only goofed
once, but that left a gougeed ring in the mirror. It still worked, and
concentrated INCREDIBLE light from a 200 W Mercury arc lamp,
but it was a VERY slow, painful process. I wish I'd thought of the
hand-made 1D pattern. I could have easily rigged up some fixture
to clamp this to the lathe bed, with a feeler attached to the cross
slide. A DVM with a continuity beeper or some similar arrangement
would have worked well. Maybe some sound damping headphones
with a beeper circuit. (I usually wear ear protectors in the shop.)

Jon