To make the jig I keep a few good looking 8’ long 2x4’s
on hand for just the purpose of making jigs and such. The one I am using has drying out for
probably a year so if it was going to warp it’s done by now. Sure enough when I set the long level on it there
was a bit of a bow so I used the same straight edge and plane procedure on it
that I had used to straighten the leg blanks.
Once that was done a couple passes through the thickness sander gave me
nice flat faces and a good reference plane.
One block at each end of the leg blank is needed to hold
it in place while being cut. They
start by taking a short length of 2x4 and cutting one edge to match the taper
of the leg. Rather than adjusting the
chop saw to cut a .8 degree angle a small spacer is set between the stop block
and the saw’s fence.
The plan is for the stop block to get screwed to the
reference 2x4 and to the leg blank.
Since the screws will run into the bottom of the project’s leg, I don’t
have to worry about them being visible in the finished project. The leg blank is longer than needed with
extra length at the top so the screw holes there can be cut off. Here is the marked-up bottom block that shows
a whole lot of layout lines. Some
explanation of them is in order. Because
the screws are not long enough to go through the block they will need to be
countersunk. The light solid lines on
the face of the block show the counter sunk depth. The dotted lines on the face show where I
need to drill a pilot hole for the threaded part of the screw to clear.
Now the drilling can commence, the left photo shows where
I have drilled a shallow 3/8” counter sink hole and am getting ready to drill
the next one. It will be drilled full
depth later but for now its only purpose is to allow me to center the pilot
hole bit (right photo) and drill it to the bit’s full depth. It’s too short to go all the way through but
it almost makes it. The screws that
will be used are self-tapping so they will finish it out. Main reason for drilling the pilot hole here
is to help get the screw started straight and square.
Now I can go back and drill the countersink holes to
their full depth. The photo on the left
shows green tape that acts as my depth gauge.
The bit being used is a Brad point drill that makes a flat bottom
hole. That’s to match the screw I am
using as it has a flat bottom. In the
photo on the right the screw driver is chucked up in the drill press and is
being used to help keep the screw square to the block.
Here in the left photo you can see the screws I used and
where one is run in until it almost comes through the bottom. I need to stop short so the piece does not
get screwed down to the drill press table.
The right photo shows a couple of things. First, you can see how the holes are offset
from each other. If they were all
centered in the block, they would cross each other and having two screws try
and occupy the same plane just doesn’t work.
I know I accidently tried it once.
Second, is that no matter how you try sometimes the drill or screw
wanders off course and they pop out the other side not exactly where you
planned. Here on the left side of the
block one is right in line and the other is well let’s just say it’s a little
bit of a free spirit.
With the two end blocks done just one last piece needed
to be made, it’s about an 8” long wedge whose taper to matched the leg
taper. The taper is laid out and the
disk sander is used to grind the angle then it is screwed in place.
All the leg blanks need to be the same exact length to
work in the jig. By using a stop block
clamped to the work bench and the chop saw I made quick work of that. Next, one of the blanks is set against the
right stop block which has already been screwed to the reference 2x4. The blank is then clamped tight to the
2x4. The other end is clamped against
the recently installed wedge and the left stop block butted up against the leg
blank. With all the pieces held pretty
close to where they will end up a band clamp is used to pull the left block,
the blank and the right stop block tight together. Two clamps are used to make sure the left
block is flush with the 2x4. The photo
bottom photo shows how all that comes together except the two clamps holding
the blank tight to the 2x4 have been removed for clarity.
Once the stop blocks have been screwed in place the band
clamp is removed and the clamps that temporarily held the leg blank in place
are put back on as shown below. You can
see the screws that will hold the blank in place ready to run in. Once that’s done the clamps removed and the
first leg is ready to be cut.
This is the setup for making the tapered leg cuts. Out of frame is a roller stand to support the
back end of the jig as the cut is started.
The 8’ level is clamped to the rip fence and a test cut about ½” wide is
set up. The jig with the securely
attached blank is then run through the saw.
The test cut is just in case anything went wrong so I could adjust and
recut without irreparably damaging a blank.
Everything worked perfect with a nice clean straight taper that is
repeatable so I reset the fence to the final width and cut all 8 legs.
Here are the cut legs and for the most part all the
problem areas were removed. I say almost
because there are still some pieces I will have to address. The bottom piece I knew about as that flaw
showed up while I was surfacing the planks.
The flaw will get filled and that face will end up going against the
wall. The cracks on the right ends will
almost completely get cut off when the legs are cut to length. In the end I have two problem children. First, the third piece from the bottom has
three cracks that showed up when I ripped the taper. The one circled in chalk is the biggest as it
wraps around and is visible from both sides.
My second problem is two of the blanks decided to twist some after cutting the taper so that could be the biggest pain to resolve. For now, I am going to set these pieces aside
to see if anything else develops or if I am lucky the twist will reverse
itself. Not a high probability of that
but sometimes lady luck smiles.
Next up – Rough Cutting 5/4 & Adjusting the Bandsaw
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