Dear Group,

For my rose engine project, I need to make my own rosettes. These
are brass discs, the majority of which have only contoured edges.
However, on some, the faces must be contoured as well to match exactly
the contour of the edge (that is, where there is a valley 1mm in from
the outermost edge, so must there be a valley 1 mm in from the highest
point on the face.

I've got some ideas based only on my independent thoughts on how it
might be done, but not at all on any actual experience of having done
any similar operations before.

1. like a brooch, maybe just shave off a few thousandths at a time.
Buy a short rectangular bar of hardened tool steel. Mount on a wedge.
EDM a precise contour; the wedge will automatically impart the bevel
so you don't need to grind that. Well, sortof. Thus you can make a
custom-contoured scraper. Mount disc on indexing head on mill, fix
scraper in locked collet, raise bed a few thousands, advance x to take
off a bite. Repeat until depth achieved. Rotate work on indexing head
for next iteration. This would be somewhat involved and tedious,
though it would yield flawless control over any contour imaginable.

2. hold plate itself up vertically in indexing head mounted in EDM
machine. If it can handle a 6" depth (I'll need to check up on that),
this might work; but the indexing head must be absolutely vertical and
dismounted so as not to rust from the water. As is apparently a common
slang adjective nowadays, this method would be somewhat "sketchy."

3. Buy a round-nosed mill of a radius smaller than the smallest
radius along the countour being cut. With a 3-axes CNC mill, carefully
programmed, this should be able to cut the contour out? I'm thinking
this to be the overall best option; efficient and effective.



what are your thoughts on any of the above
ideas, or do you have any better alternatives? Again, I'm really not
sure how this is done conventionally, these are just guesses based on
what I think might reasonably work with no knowledge of how it has been
done before, which might be much more inetelligent.


thanks!
-Bernard Arnest

"Bernard Arnest" wrote in message
ups.com...
Dear Group,

For my rose engine project, I need to make my own rosettes. These
are brass discs, the majority of which have only contoured edges.
However, on some, the faces must be contoured as well to match exactly
the contour of the edge (that is, where there is a valley 1mm in from
the outermost edge, so must there be a valley 1 mm in from the highest
point on the face.

I've got some ideas based only on my independent thoughts on how it
might be done, but not at all on any actual experience of having done
any similar operations before.

1. like a brooch, maybe just shave off a few thousandths at a time.
Buy a short rectangular bar of hardened tool steel. Mount on a wedge.
EDM a precise contour; the wedge will automatically impart the bevel
so you don't need to grind that. Well, sortof. Thus you can make a
custom-contoured scraper. Mount disc on indexing head on mill, fix
scraper in locked collet, raise bed a few thousands, advance x to take
off a bite. Repeat until depth achieved. Rotate work on indexing head
for next iteration. This would be somewhat involved and tedious,
though it would yield flawless control over any contour imaginable.

2. hold plate itself up vertically in indexing head mounted in EDM
machine. If it can handle a 6" depth (I'll need to check up on that),
this might work; but the indexing head must be absolutely vertical and
dismounted so as not to rust from the water. As is apparently a common
slang adjective nowadays, this method would be somewhat "sketchy."

3. Buy a round-nosed mill of a radius smaller than the smallest
radius along the countour being cut. With a 3-axes CNC mill, carefully
programmed, this should be able to cut the contour out? I'm thinking
this to be the overall best option; efficient and effective.



what are your thoughts on any of the above
ideas, or do you have any better alternatives? Again, I'm really not
sure how this is done conventionally, these are just guesses based on
what I think might reasonably work with no knowledge of how it has been
done before, which might be much more inetelligent.



Um, unless I misuderstand what you wish to do, a lathe and some careful
measuring oughta do this...