Well here are the pictures of one of the knuckle joints that have been completed.
Layout is everything for this joint and sharp chisels are important, since this is white oak. When I cut the fingers on the joint I used David Charlesworthâ€™s method. His technique was to use a band saw instead of a table saw, which could introduce more errors. If you use the table saw and there is any saw dust or should your sled be a little worn, or the end of the board is not perfectly at 90 degrees, your joint could either rise or fall when in operation. With the band saw the boards need to be flat and parallel, eliminate some of the possible error.
Using the band saw require a spacer that is the same thickness of the saw blade kerf (Eli suggested that this spacer is made from the same type of wood that is being used). This method only requires two fence adjustments. Highly recommend that a practice joint is completed first to determine how the spacer works. (Also, get a copy of Charlesworth Volume Two and review page 99 â€¦he has good direction on how to use the spacer)
Start with at least a 37â€ board to insure it will be long enough for the tenons for the legs.
distance between holes to be six and half inches.jpg [ 285.49 KiB | Viewed 6882 times ]
This first picture is to figure out the center of the board and than measure 3 Â¼â€ from the center to get the 6 Â½â€ distance between the knuckle joints.
Determining Cut Lines and Knuckle Joint location.jpg [ 321.2 KiB | Viewed 6882 times ]
Draw the circle and line (the line is on the leg side of the joint.
Layout the joint on the moving arm (swing portion of the joint)
Layout fingers of the joint using a set of dividers
Making the space for the band saw
band saw waste between fingers of joint.jpg [ 279.94 KiB | Viewed 6882 times ]
Cutting the fingers on band saw
Cutting the fingers on the band saw with spacer
Cutting a 45 to start the knuckle
Forming the partial knuckle
Cutting the waste between the fingers using a band saw
start cutting for the 45 degree reliefs.jpg [ 243.92 KiB | Viewed 6880 times ]
Hand saw the start of the 45 for relief area on backside of joint
Front view of the 45 degree relief cut.jpg [ 221.5 KiB | Viewed 6881 times ]
Front view of hand sawing
Using a jig to chisel out the 45 for allowing the joint to swing open
Check drill press fence for square
Align the fence the proper distance using a centering rod and the joint
Short metal rod in position to finish drilling hole for joint.jpg [ 284.75 KiB | Viewed 6878 times ]
Drill a hole in the drill press bottom to accept a Â¼â€™ steel rod to help align the hole to finish the hole (make sure to put wax on the steel rod this help get the rod out later)
Pictures of the finish joint