"bent" wrote in message
...
You know when you see the representation of the x, y, z axes for
Cartesian co-ordinate system. You can make the symbol with your
fingers, like you're at a heavy metal concert. I need to make
quarter round meet on the inside of a closet. The trim goes up
the inside laying vertically on the 90° corners, and the same
trim also meets going laying horizontally both left to right and
front to back. To trim out the top square of whiteboard, which
is the ceiling of the closet, and the peg board, the three
sides. I know how to cut a 90° corner from the same trim to do
the back of a closet, but how to put a third piece "normal" to
those. Can you cut all 3 at an equal angle, or do you have to
cope one(s) into the other(s)?

p.s. The quarter round isn't just plain quarter round. I made
my own. I took a 3/8" beading bit to 1/2" x 1/2" plain quarter
round, for a little more class. Leaves a 1/16" lip. More or
less the same idea.


This isn't as bad/difficult as it seems.

Just treat each of the three surfaces (side, back, ceiling) as their own
individual 90-degree two-way join.

The 'simplistic way' is to simply cut each join at a 45 degree miter.
you'll have two such cuts on each piece of 'quarter round'. If the
corner angles are not _all_ a "perfect" 90 degrees, you'll end up with
minor (or maybe 'not so minor') gapping that will have to be 'filled'.

The 'right way' is to do 'coped' joints, instead of mitered ones.
One piece (typically the _back-ceiling_ piece) is put in full width,
with butt corners against the sidewalls.

the next piece (typically the side/ceiling) is then coped to fit snugly
against the back-ceiling piece.

Then the last piece (typically, the side/back) is then coped to fit
snugly, *first* against the back piece, and *second* against the side piece.