The welded headtube structure is mounted on the fixture (remember the fixture?) and the ID bored for the bearings. I figure a .001" press fit is good.
You're looking at the frame clamped in the frame jig. It's not fancy, but it is effective, and didn't take forever to build. When I'm finished with this project, I'll take it all apart and use the metal for something else...
Here I'm building the bevel drive that splits. Basic construction technique is bits of Tig-welded steel mostly covered with sculpted bondo. I'm working off an Autocad drawing, so the important steel parts are carefully machined and accurately positioned.
Progress as the shape starts to emerge.
The two sides. Perforated steel is used for the shape of the outside cover. If you look closely at the inner cover, you can see beauty and simplicity of the bevel drive. The front cylinder drives from the crank, and that bevel drive spins the rear cylinder and mag drive, which are at a 90 degree angle. The scribed lines below illustrate the intersection point, which is about 7/8" above the centre-line of the crank.