Re: CNC Etch-A-Sketch, EggBot

Hi Gordon,

I've been thinking about it too. Since I've got a digitizing probe, a
rotary table and a tailstock for the Sherline mill, I can visualize a
setup that will be able to "digitize" an egg! A "compliant" pen mount
could also "draw" on the egg.

I really like the use of the NEMA #17 (?) motors in this application for
the kids. Readily available from old floppy drives. And the novel 'Z'
axis motion is one I hadn't though of!

I didn't ketch how you were going to "sense" on the probe's pivot.
Deviation on a probe tip would be simple trig calculation from the angle
that is sensed. Radial angle of the 'Z' axis would be a little
different approach!

I'm still trying to get the Gcode generated from the digitizing into STL
data (sidetracked).

Alan KM6VV


Smoke wrote:

>
> I believe I can fix you up there.
>
> Use a "drag" probe and special software.
> Run the probe back and forth in the X direction.
> The end of the probe drags along the surface of the egg.
> The probe pivots in the X direction as the end moves along the surface of
> the egg.
> The angular deviation of the probe as it moves along the X axis needs to be
> measured at regular intervals.
>
> By knowing the length of the probe and the angular deviation, a series of
> points can be calculated, from which the curvature of the egg can be
> determined. One of you software geniuses can figure out that part.
>
> Smoke
>
> > Hi Rick, Allen,
> >
> > Great site! I really enjoyed reading about the EggBot! Almost makes my
> > two boys (22 & 19) were young enough to make them!
> >
> > I'm wondering if any of our CAD/CAM *EGGHEADS* can suggest ways to track
> > an egg's surface?
> >
> > Alan KM6VV