Friday, December 4, 2009
Making a Plane Adjusting Hammer
After I started using my new fillister plane, I decided I needed a real plane adjusting hammer. This is what I came up with, not exactly a groundbreaking new design, but easy to make and works well. The head is made of 1/2" brass rod, with a 1/2" long ebony facing on one side. The ebony is attached by a machine screw that is tapped into the brass and the ebony. This is where a bottoming tap comes in handy. Unlike a normal tap, which doesn't have complete threads towards the front end of the tool so that the tool can be started easily, the bottoming tap has threads that go all the way. It is used after the normal tap has threads established. This allows threads to be cut all the way to the bottom of the blind holes, thus making it the strongest possible. The two pieces are joined with the addition of epoxy. The I drilled the hole for the hammer's tenon. This is tricky because the hole must be drilled into the curved side of the brass. So I took a piece of scrap pine, drilled a 1/2" hole in it, and a perpendicular 3/8" hole that intersects the 1/2" hole. This guides the drill bit and prevents wandering. I aligned the hammer head up with hole and drilled it out. After letting the epoxy set, I trimmed down the ebony, using the brass rod to reference my chisels off of. I domed each face of the hammer with a file. The head gets polished to 600 grit.The handle is black and white ebony, made into an octagon. When making an octagonal handle, it's best to rough it out with something like a block plane, and go back later with a smooth plane and clean up any tearout. Use a very thin cut, and a sharp blade. the handle is about 7" long. I formed the tenon that goes into the hammer head, and planed a taper into the top to make it look better. Then the hammer head is epoxied on, and the whole thing got three coats of shellac.