Mark ( on March 17th, 2009

There’s still more work to do on the rockers and back braces but for now I have them on hold. However, with the joinery on the seat blank complete, I needed to complete the work on the front and rear legs so that they will mate with these joints in the seat.

As you will recall, in my last post I created the joints in the seat that will receive the legs.  These joints essentially have a tongue that must mate with a corresponding grove in the legs. There’s a bit more too it, as you will see, but that’s the basic premise.

Before I could create this joinery on the legs, I needed to do two things: for the rear legs, I needed to create profile on the inside faces and visible from the front and on both the front and rear legs I needed to add some material to make parts of the legs wider.

rear-leg-front-profile-outlinedrear-legs-with-front-profile-cutIn the pictures you can (barely) see the outlined profile toward inside of the rear legs which was to be cut on the band saw.  Because the legs had already been contoured, these cuts were a bit tricky.  I was careful to be sure that there were always two points of the leg in contact with the saw table – sometimes one of those points was at the edge of the table as the leg was either entering the table or leaving the table. This allowed the cut to be completed safely even though it was sometimes happening at a point elevated above the table. In the second picture you can see the profiles cut on the inside of the rear legs.

gluing-adder-piece-to-rear-legsripped-adder-pieceAfter profiling the rear legs I milled adder pieces for both the front and rear legs.  The front adder piece runs the length of the legs. The rear adder piece runs just between the sections that will eventually contact the seat.  For the front legs, the adder piece will be profiled to become the outside of the legs. For the rear legs the adder piece was ripped at the band saw after gluing in preparation for more detailed operations to follow.

ripping-rear-leg-adder-piece-at-6-degrees-1ripping-rear-leg-adder-piece-at-6-degrees-2ripping-rear-leg-adder-piece-at-6-degrees-3The rear legs of the chair need to cant outward at the top at an angle of six degrees.  In order to accomplish this, the adder pieces on each rear leg must be ripped at six degrees from the outside faces of the legs.  In order to accomplish this, I created a jig to use at the table saw.  The jig is designed to ride against the fence on the saw and it has a fence of it’s own that is fixed at six degrees to the table saw blade.  With a leg clamped to the jig the piece was pushed through the blade cutting off a six degree wedge. For the other leg, the jig was rotated 180 degrees and the other leg was cut in a similar fashion.

flattening-seat-transition-on-rear-legsrear-leg-seat-joint-layoutI took this opportunity to clamp the legs together in the vise using the angled offcuts from the previous operation so that I could smooth the seat joint area and square it to the angled faces which were previously cut on the table saw. After achieving smooth and square faces, I laid out for the joinery that will join the legs to the seat.

cutting-notches-in-rear-legcutting-notches-in-rear-legThe notches to accept the seat joinery were cut on two faces of the rear legs using a sled on the table saw.  Because each leg had only a small bearing surface resting on the sled, I clamped a block to the outboard side of the legs to prop them up at the correct angle.  One leg was cut in the orientation as shown in the picture and the other leg was done at 180 degrees from this orientation. The notches were nibbled away with repeated passes of the leg over the table saw blade until the joint would just fit the seat. Once the rough notches were cut, I cleaned up the saw marks with a shoulder plane.  rounding-over-rear-leg-jointrear-leg-fit-to-seatThe last step for this joint was to round over the inside corner of this joint to match the corresponding rebate that was cut into the seat.  I did this with a ¾” round over bit in the plunge router.  Because of the small size of the area where I could rest the router, this did not give optimal results. So, I subsequently repeated this step with the same bit in the router table.  In the picture, you can see the general fit of the rear leg into the seagluing-front-leg-adder-piecet.

completed-front-leg-joint1The front leg joinery was done in a similar manner to the rear legs.  However, the notches were made on three faces of the legs. Also, this joinery was done prior to gluing the adder piece to the two front legs.  In the pictures you can see the competed front leg joinery and the adder piece being glued between the outside surfaces of the two front legs after the joinery was completed.

Next up: Sculpting the seat

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