On Sat, 12 May 2007 01:10:42 -0500, "Morris Dovey"
wrote:

I have a router table with a behind-the-fence 2-1/4" port for
attaching a Shop-Vac. I've been thinking of inserting a cyclone
separator to avoid having to empty the Shop-Vac so frequently.

I have a small steel barrel about 19-1/4" in diameter, and it should
be no big deal to make a plywood lid. What I don't have are the
30-degree and 90-degree flanged fittings.

This evening, I realized that I could cut 3-1/2" x 3-1/2" squares from
cutoffs, drill a 2-1/4" hole in the center, and glue 'em together to
make a square "pipe" - then saw the pipe in half on the diagonal to
produce not one, but /two/ intake fittings. The result won't be
exactly 30-degrees, but it'll be "close enough".

My drawing shows four 2x pipe segments, but the segment thickness
doesn't matter.

I'm thinking of using a template and drilling four 1/4" holes so I can
use dowels to ensure alignment (and perhaps add a bit of strength),
but this extra work is purely optional.

A fifth 2x "pipe segment" will be used in the center of the lid as the
outlet connector for the Shop-Vac's hose.

I plan to position the two connectors and trace the holes with a
pencil - then drill and use a jig saw to cut matching holes in the
lid. When that's done I'll just glue my hose attachment fittings to
the lid.

I'm still trying to figure out what to do with the second one. :-)

Okay. Gotcha. Are you going to cyclone in a helical shape down the
sides of a cylinder? That way you wouldn't need a cone shape... I
imagine you could shape a spiral flange guide out of flat sheet metal
and pop rivet it to the sides of the cylinder. Love to see a pic when
you finish it up and hear how it works.

Bob the Tomato