Before I get into progress on the mockup I have had a couple
of questions. First, was how long do I
spend in the shop a day? Right now it’s
about 3 hours or so a day 6 days a week more or less. Second question asked about using dowels vs biscuit
joints. This was easy for me to decide
because I don’t have a biscuit joiner.
If I had one I probably would have gone with it over the dowels because
I could have adjusted its fence and not had to build the 3 degree jig to drill
the holes for the dowels. Also, the biscuits
would have allowed some side to side slip for alignment.
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| 5 Degree Jig |
The leg joints in the seat are constructed in two
steps. First is a cutout for the leg and
second is the routing. Together they
form the seat half of the mortise and tenon joint. The back leg cutout is first and is not a
simple square notch. Since the back
legs splay out, being wider at the top than at the bottom the joint needs a 5
degree angle. The setup is to align the
crosscut fence at 85 degrees. Well,
really the first step is to make a jig so I could repeatedly and accurately set
the 85 degree angle between the fence and the blade. That required me to dig back to my high
school geometry class to find the formula to calculate the base of the triangle
knowing two sides and an included angle.
That took longer than I care to admit.
Having cut the jig I used it to set the crosscut fence at the correct
angle then set the blade for a 3” deep cut.
Since this cut is from the narrow end of the board I clamped the board
to the fence to make sure it stayed in place. Clamping it in place also let me keep my fingers away from the blade.
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| Cutting 5 Degree Angle |
The first pass through the saw was to check for proper alignment and as
shown here it matched the required angle.
The second cut is right to the layout line.
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| First Cut Close to the Line |
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| Finished Cuts |
The legs are mirror copies so once I made the
cut on the right leg I had to re-set the fence (using the jig) for the left leg
and make the same cut. With both angled
cuts made I reset the crosscut fence back square to the blade and cut the other
side of the notch. However, because of
the 5 degree cut the block does not come free so there is some minor work with
a hand chisel to clean up the joint.
The dado for the front leg joint is pretty simple but, it’s
here that I ran into the first small problem.
The plans called for the dado to be 1½” back from the front of the seat
while the DVD showed 1¾” back from the front.
Stuck and not knowing how critical this dimension was to the overall
geometry and center of balance I looked up the author’s email and sent him a
short note asking for clarification. I
really did not expect a reply but the very next day there was a note from Scott
explaining what was going on, “The 1 3/4" measurement is as measured from
the front of the RAW chunk of wood. The
1 1/2" measurement (as depicted on the template) is obviously from the
front of the template. There is a slight
difference between the raw chunk of wood and the front of the template.” Needless to say I was impressed that he
replied to me and how quick the answer came back. Back to the shop where I marked the cut, set
a stop block and with three passes using a stack set of dados made the
cut. I should explain here that the
stop block registered on the back leg notch is used so the dados are exactly
the same distance for the left and right side.
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| Cutting Front Dado |
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| 5 Degree Angle Bits |
With the cutouts done the second part of the joint, the
routing, could be worked on. The front
leg joint uses a straight router bit to make the ¼” wide cut on the top and
bottom. The back legs require a total of
three different bits to compete. Remember
the 5 degree cut made on the table saw?
Well, two different bits are needed to make the cut to match that
angle. From the top the 5 degrees needs
to slant one way and from the bottom the slant needs to go the opposite. The square part of the cut can use a regular
straight bit. Here is where I made my
first oops. I knew I had to order the 5
degree angles bits but I had a straight bit that matched the cut width of the special 5
degree bits. What I did not realize
until I was ready to make the cut was that the diameters of the bits all had to
coordinate so the interior radius at the corner of the cut would match. This brought everything to a standstill while
I ordered and waited for the appropriate straight bit to arrive. I did go ahead and make a test set of cuts with the two angled bits on a scrap piece to see how they worked.
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| 5 Degree Cut and Routing |
Next up – Getting & Rough Cutting Chair Wood
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