Re: ATM making small alt bearings

["Bill T." <twentiethwave@hotmail.com>]

You can make very precise plywood circles with a disc sander.  Draw an
accurate circle on the wood with a sharp pencil and a protractor (i.e. a
piece of wood with a nail pivot, and hole for the pencil).  Rough cut the
circle with a saw, then sand down to the pencil line with a 120 grit or
finer disc.  With a little practice you can easily split the pencil line.

You can also use a drill press...bolt the rough cut discs onto an all-thread
shaft, run the press, and trim with a sanding block.

In any case stack up both discs and do them at the same time.

John Dobson likes to use plastic dishes for altitude bearings on small
scopes.  Drill a few holes and screw them to the tube box.

Bill T.