Re: [CAD_CAM_EDM_DRO] Re: DIY probing

Hi Chris,

Why can't you just work from the outside of the bell, aren't they still
raised from sheet brass? I think my first approach would be to try a
shadowgraph technique - literally. Hang a big piece of graph paper on the
wall then shine the light of a slide projector on this with the horn in
between. By moving the horn back and forth you could adjust the size to a
known scale and then just mark the shape on the graph paper and take all the
relevant dimensions from that. I realise a 'technical' solution might be
more aesthetically pleasing but I doubt the guy who hammered the brass in
the first place worried too much about that!! <G>

Ian
--
Ian W. Wright
Sheffield UK
www.iw63.freeserve.co.uk

----- Original Message -----
From: <ccs@...>
>
> Just to explain, I'm trying to probe the inside of a french horn bell
> (in to the start of the curve) to determine its shape. Current idea
> is a table with a cutout the size of the rim - horn is clamped under
> that with the bell opening up. Gantry arrangement moves over this and
> lowers probe down into the bell. Just occured to me I can probably
> borrow the sherline mill Z axis to carry the probe and maybe even the
> X and Y motors to run the gantry, since it need not go particularly
> fast. Of course the temptation would then be to make it heavy enough
> for milling ;-)
>