Re: Lettering on a circular surface...

--- In CAD_CAM_EDM_DRO@y..., flyspeck1@a... wrote:

>
> There are several programs out there that will generate
> G-code for lettering. To that end, they all are
> designed to work with a normal "flat" surface. But what
> about lettering on a handwheel? To get the best
> lettering you would have the table movement limited to
> the Y-axis and a rotary axis (rotary table whose axis of
> rotation is parallel to the Y axis). Each of these
> would move in tandem with one another to create a
> character of uniform depth.
>
> My thought is that ultimately this is almost identical
> to an X/Y table movement. Not having played with a
> rotary axis, however, I don't know if they are typically
> handled differently in G-code. Logic would seem to
> indicate this is the case as your positioning is limited
> to 360 degrees. You are not, after all, moving 5", but
> rather 45 degrees (for example).
>
> So my question is two-fold. Can one simply take the X/Y
> output from existing programs and use this with a CNC in
> which the X axis has been hooked up to the rotary table
> (properly calibrated, of course). I *think* this will
> work, but of course the calibration would be a function
> of the part radius. Alternatively, is there an
> application out there that is designed to work with a
> rotary axis (which would take the part radius as an
> input parameter)?
>
> I guess this really comes down to the generic "what
> application generates code for the 4th axis, and what
> does that code look like" question.
>
> Sorry if this is a brain dead question... I have never
> played with a rotary axis before.
>
> Thanks,
> Alan

It would be possible to hook your radial table up as an X axis you
could calculate the amount of rotation to equal the X movement You
would have to recalutlate it for each diffent diameter that you use
though. ie. a 6" diameter would not have the same movement as a 3"
diameter. I suppose you could figure a formula once you found your
intail steps per inch of outside revolution. Actually this sounds
like it might be a fun little project I may try it. it would actually
be fairly easy to do I think.

Jeff Tice