The table itself is built from a half inch thick aluminum plate.
The plate has a slot cut most of the way through the middle for the tablesaw's
blade. There is a front support to keep the plate from flexing.
The plate has a set of ball bearings that run in the saw's miter slot.
An array of ¼-20 holes on 2" grid allows arbitrary placement
of toggle clamps or other accessories. The clamps can hold small pieces of
wood securely so that the operator can keep his hands safely away from the
saw blade.
An adjustable rip fence can be mounted and used for precision rips of
small stock or for defining the width of a cross cut.
There are two rear fences that can be placed perpendicular
to the saw blade for
use with the adjustable rip fence or when using the jig as a plain miter sled.
The rear fences can be moved to 22½°, 30°, 45°, 60°, or
67½° from perpendicular for cutting precision miter angles.
The adjustable fence rides on two precision ground stainless steel rods
and is controlled by a stainless steel lead screw. A dial indicator gives
an easy way to read the actual location of the fence. The fence is adjustable
over a 2" span, but the whole mechanism can be placed in one of seven
locations on the base plate spaced 1" apart. This gives a total range
of 8". Registration is provided by a pair of tooling pins visible in the
right hand image.
This shows the adjustable fence moved to its far left position on the table.
The bottom of the aluminum plate has HDPE (High Densit PolyEthlene) strips
to reduce friction and let the table slide easier. Three ball bearings
control the motion of the table. Two of them are fixed and determine
the accuracy of the cut angles. They register the location of the plate to
the right edge of the left miter slot on the saw. The third ball bearing is
adjustable over a small range to allow for slightly different sized miter
slot widths. These bearings provide a three point reference to determine
the location of the plate. I also put some pins in the bottom near the
bearings. In normal use these don't do anything - they shouldn't touch the
miter slot walls. However, when the table is placed on some surface, they
protect the ball bearings from impacts.
The adjustable fence can be removed to allow the sled to be used as
a traditional miter sled. The rear fences can be left perpendicular to the
blade or set at angles of 22½°, 30°, 45°, 60°, or
67½° and fastened with ¼-20 bolts. Registration of the
fence is provided by a pair of tooling pins located at each end of each
rear fence piece.
This shows a more level view of the table. The front support piece and
the two rear handles for the operator's hands are clearly visible.
I'd like to thank my machinist friend Lynn King for the untold help and advice he gave me during the course of this project. Without him, I wouldn't have been able to build this.