I made a fairly large, heavy duty one that has a single runner slide on the
supporting jig. The blade stays vertical.

The jig is simply a 45 degree sled with 'T' slots for clamps to hold various
widths of boards. The board to be mitered is registered against a 'fence'
on the near side. This insures a 90 degree alignment of board to path of
blade. The clamps hold the work piece to the jig. You first cut your work
piece to just over length and slap it in jig and then push it through the
blade.

The first cut throught the blade also cuts the jig to fit the blade.

Voila! 45 degree miter up to the width of the jig. Length of board can be a
bit longer (sqrt of 2 times x) than the height of ceiling above table
saw...or move it outside for the really ambitious projects.



I like to make boxes using miter joints and splines or miller dowels.
I sometimes use boards as wide as 15" and would like to make a
jig/sled to cut the 45 degree edge miter as accurately as possible on
my table saw (left tilt). I have in the past used a quickly thrown
together one runner sled for this out of a piece of plywood. Having
recently put together a really nice 2 runner crosscut sled I was
wondering if anybody had any good tips on building one for crosscut 45
degree cuts.


Once again, Fred Bingham's, Practical Yacht Joinery covers the subject.

(Uses a factory corner from a sheet of 3/4" plywood)

Lew