"whit3rd" wrote in message
...
On Saturday, June 24, 2017 at 8:13:25 PM UTC-7, JBL wrote:
I am attempting to make a few "dovetails" which are brackets used
to
attach a telescope to a telescope mount....

I thought I'd be able to get away with an old circular table saw I
had.
Last week, I made some 1/4" thick dovetails of a slightly different
design using my table saw fitted with a plywood blade.

You can get metal-cutting (carbide) blades, and can get 'em ground
for a
60 degree bevel on the edge, so that the blade cuts one sidewall of
a
dovetail socket. It's easier, though, to get a bar and bevel its
edges, for
the male half of the dovetail, then another bar beveled at the edges
can be ripped in two, and the halves mounted on a plate to form the
dovetail female.

Don't write off your saw just yet, it could have something simple
like
metal shavings in the brushes. A cleaning and some lube can bring
it
back to functional.

If a track is what you need, there's suppliers that can deliver it
by the millimeter,
with lots of options.
http://www.igus.com/drylin

The table saw I chose for cutting aluminum with a carbide blade and
sheet steel with an abrasive disk is an old Craftsman that has the
blade on a fixed arbor which extends out the side to a pulley. The
table tilts instead of the blade. The saw is on a plywood table with
the motor underneath, shielded from metal chips or abrasive particles
and sparks. The motor mount is hinged so its weight tensions the belt
which slips if the saw blade or abrasive disk binds. I jam a hockey
puck under the motor mount to adjust the belt slip.

Since I have more tools than storage space the motor is part of a
belt-disk sander that can be flipped up to use it, or down to use the
saw. Either way gravity tensions the belt. It isn't the fastest
cutting machine but it tolerates jamming well and gives me some
ability to cut metal larger than my more precise machines can handle,
such as 4'x8' sheets.

The hinge it flips around is a pipe across the center of the plywood.
The saw is raised to clear the pipe and make blowing out sawdust
easier when I switch from cutting wood to metal.
-jsw