Most of my woodworking projects seem to start with tool making.
On the right is a 1/2" stub spindle for a shaper that I've never used. Next is a standard 3/4" to 1/2" bushing. I took the 1/2" straight cutter in the center and counter bored it so an upper bushing would set in flush. It took several tries to get the cutter mounted in a 3 jaw chuck so the bore and counter bore would be concentric. I turned the countersunk bushing on the right to fit the bore and counter bore of the cutter. Finally there's a machine screw that holds this all together.
Here's the setup on the shaper. The end of the work piece has been miter cut. A parallel shoulder was cut, and most of the rabbet wasted away. Several passes with the tool on the stub spindle flatten the face of the joint precisely until the undercut parallel to the shoulder is made when the shoulder hits the stop board.
This is what the edge and face of the joint look like. A single setup makes both sides of the joint. In English Historic Carpentry this is called a face-halved and bladed scarf joint and its origin traced to the 16th century. The parts are about 2" thick by 7" wide, and the overall joint is 6" long.
Finally, here is a pair of hammer beam braces with the scarf joint in the center of the curved support. I've tried several methods for joinery of this type over the years, and this worked the best by far. The curves are very fair and uniform. The tenoned joints where the small diagonal meets the curved brace have matching curved shoulders, and these are both hairline tight on both sides--a big consideration for weathering. I think I knew for a long time this was the right way to do this, and it ended up being easier than I thought.
On the right is a 1/2" stub spindle for a shaper that I've never used. Next is a standard 3/4" to 1/2" bushing. I took the 1/2" straight cutter in the center and counter bored it so an upper bushing would set in flush. It took several tries to get the cutter mounted in a 3 jaw chuck so the bore and counter bore would be concentric. I turned the countersunk bushing on the right to fit the bore and counter bore of the cutter. Finally there's a machine screw that holds this all together.
Here's the setup on the shaper. The end of the work piece has been miter cut. A parallel shoulder was cut, and most of the rabbet wasted away. Several passes with the tool on the stub spindle flatten the face of the joint precisely until the undercut parallel to the shoulder is made when the shoulder hits the stop board.
This is what the edge and face of the joint look like. A single setup makes both sides of the joint. In English Historic Carpentry this is called a face-halved and bladed scarf joint and its origin traced to the 16th century. The parts are about 2" thick by 7" wide, and the overall joint is 6" long.
Finally, here is a pair of hammer beam braces with the scarf joint in the center of the curved support. I've tried several methods for joinery of this type over the years, and this worked the best by far. The curves are very fair and uniform. The tenoned joints where the small diagonal meets the curved brace have matching curved shoulders, and these are both hairline tight on both sides--a big consideration for weathering. I think I knew for a long time this was the right way to do this, and it ended up being easier than I thought.