Drill the inner hole1/2" or so. Rough cut the OD. Mount on an arbor
and turn the OD to spec on the lathe. Remove the arbor, clamp the
piece in a 3 jaw chuck and turn the ID. None of the options you list
will provide the edge finish or accuracy you need.
JR
Dweller in the cellar
On Tue, 29 Jul 2008 17:41:44 -0700, "Michael Koblic"
wrote:
Another recent thread got me thinking:
In the near future I shall have to cut a doughnut like structure from
0.5-1.0 mm brass. The outside diameter 114 mm, the hole diameter 57 mm. The
cut has to be a) clean and b) reasonably accurate (within1 mm).
There are number of options:
1) Snips
2) Fret saw
3) Jig saw
The concern is about the final edge appearance with these three. I fear that
even supported the edge is going to get ripped up by the saw (especially the
jig) and there will be some bending with the snips.
I have never used a hole saw and I believe that sizes reasonably close to
those above are available. How good are these things at producing clean
edges?
Another option I was wondering about is using a router with a straight 1/4"
cutting bit. I have a very nice small circle jig which allows for increasing
radii by 1/16" and does a really nice job in wood. Has anyone tried this
with brass or aluminium? I am thinking supporting the brass plate on a piece
of wood and having at it.
Finally, thre are these Roto tools for cutting dry wall which come with bits
ostensibly capable of cutting non-ferrous metals. I tried one of these bits
in a Dremel tool cutting kydex freehand but not with great succes due to
lack of control. Some sort of jig would definitely be needed. The advantage
is that the bits are about 1/8" diameter.
My supply of brass is limited and I am trying to make sure that I know what
I am doing rather than using a "try it and see" approach.
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