As I was checking the dado, I noticed a couple of places
that the dado blade had not cut to its full depth. Probably because I was not holding the piece
tight enough to the table saw’s top. I
could have reset the fence and recut that part of the dado again but decided to
use a hand router I made in 2020. It’s
easy to use for the small bit of touchup needed. Just set the blade in the router to the
desired depth then gently run it along the dado using the two knobs for
control.
Because the Fixed Back is sized to just fit the dado a
small hand plane is used to make a small bevel on the long edges that fit in
it. The top photo shows the Fixed Back
in the vise and the hand plane used.
Bottom photo is a closeup of the bevel.
Here you can see how the two pieces fit nice and tight
together.
Drilling the holes for attaching the Fixed Back to the
Base with screws is next. With the two
pieces still together the hole locations are laid out on the bottom face of the
Base. First, using the thin drill bit (on
the left) drill a hole the same depth as the screw on the right’s length. Second, is to disassemble the pieces then use
the countersink (center) to taper the top part of the hole so the screw head
will be just below the Base’s surface.
Last is to use the right drill to make a clearance hole just big enough
so the threads on the screw do not bite into the Base. Since the screws are used to pull the Base
tight to the Fixed Back the Base needs to be able to move up and down the
screw.
Before assembling the Base and the Fixed Back the Side
Braces get made so I can clamp them in place to help square the Fixed Back to
the Base. There are two, one at each end
of the jig shown in the top photo. They
are cut from a small piece of ¾” thick oak veneered plywood on the table
saw. So, I don’t whack myself when using
the jig, the exposed corner gets rounded.
After laying out the curve the bandsaw is used to rough cut the curve.
Smoothing the bandsawn edge is done with the large disk
sander. The bottom photo shows the
smoothed finished edge (except for hand sanding) on the left and the bandsawn
edge on the right.
Gluing and screwing the Base and Fixed Back together is
next followed by clamping the Side Braces in place.
After checking to see if the Saw Slot Runners still run
true in the saw’s miter slots they get a tiny rabbit cut on either top
edge. The inset is a closer look at the
router bit and notch. This should give
any glue squeeze out that happens when they are glued in place a space to ooze
into so the jig does not get glued to the table saw’s top. It will also make any minor adjustments needed
after they are glued in place easier to do.
The red arrow points to the notch cut by the router. Just to its right is the second Runner
flipped over so the rabbits are easier to see. 
Gluing the runners to the Base is next. The top photo is the first step where a thin
shim has been set in the miter slot.
It’s thick enough so the top of the runner is about 1/16” proud of the
saw’s top and the fence is set to act as a reference to make the Base square
with the saw blade. The bottom photo
shows the runners in place ready to have a thin bead of glue applied so as to
minimize squeeze out.
Next shown in the top photo is after the Base assembly
has been set in place on the runners, butted up tight to the fence so it’s
square with the saw blade and two clamps placed to apply pressure to the glue
joints. The bottom photo is of the back
side where two more clamps are used to apply pressure to that side of the
jig. After letting the glue cure
overnight, the clamps come off and the assembly tested to see if it runs
smoothly and if not, the runners are adjusted as needed. Over the years I have made several jigs that
use runners like this and they have always needed a certain about of adjustment
to get a smooth fit. This is the first
time where they fit perfectly the first time.
It is also the first time I have used the saw’s fence to square the
assembly and the first-time using clamps to hold everything in place while the
glue cures.
While the glue would probably hold the runners solidly in
place I added a few screws for some mechanical fastening, just in case. The screws used are not flat head but round
head as shown in the top photo. Flat
head screws are not used because their tapered underside would act like a wedge
causing the runner to widen slightly binding the runner in the saw’s miter
slot. The inset shows just the head of
the round screw with its flat underside so you can see what I mean.
The drill on the left is a Brad point type that makes a flat bottom hole
which matches the underside of the screw head.
The next bit over is used to drill a clearance hole though the runner
for the screw itself. Tape is used to as
a guide to mark the hole depth. The
bottom photo shows the runners with all the mounting holes drilled and a couple
of the screws installed.
Next Up – Attaching Side Braces, Spacer Base & Moving Index Assembly
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