Re: [CAD_CAM_EDM_DRO] Re: Scanner/Digitizer skip function/probe details?

Alan Marconett KM6VV wrote:

> Dave,
>
> Yes, I was thinking about that, an encoder wheel on a dial indicator, or
> a photo-interrupter actuated by a vane (needle) moved by a contact. Or
> strain guages. What I haven't figured out is how to get 3D. 2D from
> the strain guages, but 3rd is tough. Maybe if object was on a rotary
> table (C axis), then we could approach in more limited directions? Any
> ideas?
>
> I'm thinking each G61 move "collects" a data point, and they are saved
> in .DLG format (Digital Line Drawing), .DEM (Digital Elevation Map),
> .DXF or Gcode.
>
> Alan KM6VV
>

> snip all my old comments and Ballendo's.

let me try this in another format: opti pair (emitter, phototransistor) at angle i.e one of the reflector types....looking at the
needle so when one gets deflection of a half thou or so you change states on the transistor.

Maybe something primitive in terms of a program: capable of doing an x,y grid at the desired granularity. Now you need something to
advance the Z axis until you get a state change....and read Z axis....this is not going to be fast. :-( Post process for to
compensate for slope, i.e. the unless slope is zero the point of contact with a spherical probe end will not be the real point of
contact( but the solution is straight trig). After compensation (correction) this gives a point map in x, y and z which will have to
be processed again to give you g-code to duplicate the surface. Naturally if you have overhangs this won't work and vertical walls
will probably need another routine which slides along the wall taking points. All in all this is not a simple process.
Hope someone has a better idea.

Dave