From: Mark Holm 
To: adams{at}rmci.net, atm{at}shore.net
Reply-To: Mark Holm 


>
> What is a beam compass, and more specifically how do you use it?
>
> ------------------------------
>

For this purpose, a beam compass is a long piece of 1x2 pine, or a long piece of
electrical conduit or anything else handy, cheap, moderately lightweight
that can be adapted to pivot near or at one end and hold a pencil or
scriber near or at the other end.  The distance between the pivot and the
scriber/pencil needs to be your planned radius of curvature.  The pivot and
scriber need to be held firmly enough that they don't wobble.  Duct tape
might work, but something a bit
  stiffer might be better.  Fix the pivot base to something handy, like the
floor.  (The attachment can be decidedly temporary, such as having your kid
stand on it.)  Put a piece of sheet metal as mentioned before, or perhaps
sheet plastic of a sort than can be worked well, where the scriber/pencil
can mark it.
  Make a mark as wide as your mirror.  Cut and file to the line.

Or, attach the template material to the compass and replace the scriber
with something that can cut the template material.  Swing the template
material, on the beam past the cutter and Voila!  (or vice versa.)  If you
have a router or a
router with a router table, or a drill press, the beam compass can be set
up in conjunction with one of these.

Or cut the template material approximately to shape, then fasten it to the
end of the beam and swing it back and forth past a sanding block until it
has the correct shape.  In these last two cases, it is the pivot to
cutter/sanding block
distance that establishes the radius.

Mark Holm

--- BBBS/NT v4.00 MP