On Sat, 24 Jun 2017 23:13:21 -0400, JBL wrote:

I am attempting to make a few "dovetails" which are brackets used to
attach a telescope to a telescope mount. If purchased outright, for the
kind of dovetails I need, the expense is beyond my budget. I recently
acquired some 1/2" aluminum sheet/ bar. The dovetail needs to be 1.75"
wide at the base, with the sides cut at a 15 degree angle. Length can
vary a bit, but usually about 12-14". My plan was to make at least 3
for the various telescopes I have.

Now is the perfect time to learn how to _really_ use a file. This is
your cheapest option and the best way to learn a necessary skill. (Now
watch you scoff at it.)


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. This went well,
but when I tried to make these thicker 1/2" dovetails today, I ended up
burning out my saw.

(Burned out your saw? Nasty comments about your IQ suppressed, but
most people know when to quit.) HSS plywood blades won't hack it. Try
carbide.


Ideas for a cheap way to make these dovetails would be welcome. I've
been watching Craigslist for another circular to replace the burned out
one, but I don't think it's the best tool for this job without a $30
plus blade made to cut metal and even then I'm not sure it will do it.

Drop by Harbor Freight and get some $5 carbide tipped blades. Oops,
they no longer make the cheapies. (Kids are screwing it up, bigtime.)
Too bad. 46231 and 00529 are some I still keep in stock. Depending on
the alloy, these C3 tips can leave a rough cut, but some alloys cut
cleanly. Avanti 10" x 60T blades are $15 at Home Depot. Cut the
angle and file the bottom corner. Or regrind the teeth to 15. This is
if you were overstating the burnout of the table saw motor. sigh

Freud carbide tipped dovetail bits for wood are 14-degrees and are $17
at Amazon with free Prime shipping, if you're a member. A router
could make quick work of it for you, if you can make jigs.

--
The Federal budget is a complex document. However, working
for a President committed to keeping his promises means my
job is as simple as translating his words into numbers.
Mick Mulvaney, Director OMB on Trump