Doing some layout work on the legs is next or at least I
thought it was going to be. Checking
one last time to see if any of the legs had moved uncovered a bit of a problem
with two of them. Below you can see the
gap at their center. What was once a set
of nice straight edges had developed a bow.
Naturally these two legs are the front ones where the door goes. Trying to put a straight square door into a
curved opening is not a good plan.
Straightening them required a bit of setup. Since the legs are tapered, I could not work
off the opposite edge. Using the router
with a ½” carbide spiral bit run along a known straight edge is the solution.
Below is the setup. Three legs are
clamped together to make a level surface and my straight edge in this case the
8’ level is clamped down so the router will take off nothing at the low point
of the curve. That ended up shaving of
just under 1/16” at the high points.
After a couple passes with the router the two legs have
straight edges and fit together with no gaps.
NOW, I can start working on the leg layout. Up until now all the legs are the same. From here on they will be split into
left/right legs and also front/back legs.
I need to carefully mark which is which as ending up with too many of
one type of leg is not that hard – that’s the voice of experience
speaking. As you can see, I do put a lot
of information on pieces to make it easy to keep track of what’s what.
The top photo below is the layout for the mortises and
the square holes for the pegs. To speed
things up and make sure the layout is the same from piece to piece I made a jig
with master layout lines. The bottom
photo shows the bottom end with the jig in place with the mortise and square
holes laid out.
Since the 3/8” mortise chisel is already set up the
through mortises will be cut first. Here
is the setup for cutting the mortise into the tapered face. The machine is set so it cuts the mortise
dead center and slightly more than half way through the piece. A stop makes sure that all of the mortises
start at the same point.
The order of cuts is to make one at each end then cuts
between them followed by cuts to remove the remaining material. I use full cuts because it equally loads the
chisel. A three-sided cut could cause
the chisel to drift stressing the chisel/drill assembly.
After all the pieces have this cut made the piece is
flipped end-to-end so the same face is against the back of the clamping
assembly. That’s so the cuts are all
registered against the same face and line up perfectly. If I were to just flip the piece over and
make the cut any difference from the mortise being absolutely centered would
keep the cuts from lining up and that’s a problem. There is one other little quirk in cutting
this face and that’s the taper. Since
the tapered face is now down the mortise would not be square to the first
setup. It’s not hard to fix, a short
piece from the original tapered offcut is put under the leg which squares
things up. With that done the second
half of the mortise can be cut so it ends up aligned with the previous
mortise. Because the leg top and bottom
mortises are not the same distance from the end of the leg the whole procedure
needs to be done with different start and stop points.
Once all the mortises have been cut a little interior
cleanup using a rasp and occasionally a chisel was needed to smooth the surface
left by the mortising chisel and clean up any small irregularities.
Cutting the square holes for the pegs in the legs is next. Here is the top half of the cabinet to give you and idea of the leg pegs.
Changing the mortising bit
from 3/8” to ½” is first. That is
followed by setting the distance the pegs are from the inside face on the
mortise machine because it is the same for all of the holes. Last is to set up a roller stand on each side
to support the leg when it is cantilevered way out beyond the edge of the
table. The center photo shows that
except the left stand is out of the photo.
The right photo shows one hole cut and my small square being used to
align the edge of the bit with the layout line.
What does not show up in any of the photos is a 3/8” spacer that fills
the through mortises so when the peg holes are drilled the interior side does
not blow out when the chisel exits.
After drilling 64 holes for pegs the legs can be set
aside until later. They well underway
now but still need; a stopped rabbit for housing the back, final sanding and
putting a small radius on some of the edges to soften them. Below are the legs and a closeup of the
bottom of the leg.
Next up are the cross pieces or rails that go between the
legs at the top and bottom. First is to
sort through the blanks to decide which ones will be used in the front, the
back, which will be the show face, its up/down orientation and marking them
accordingly.
Since the rails are 1 1/8” thick and the legs are 1 3/8”
thick and I want the inside faces flush means that the tenons are not centered
but offset. Add to that the bottom
tenons are not centered vertically means there will be lots of places where
things can go very wrong very fast.
Looks like I will be doing a lot of measuring and double checking before
cutting.
Next up – Starting the Leg/Rail Tenons
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