First off, thank to Phil and Mark Kingham for doing the machining of this thing. I don't have a lathe and they do.
I recently bought a set of ND Miata wheels for $100 to experiment with. I wanted to see if I could "machine" the center bore to make it fit my MINI. A 3/8" bearing on a 1/2" router finishing bit and you can cut the aluminum readily, but the result will be a little over 57mm diameter because it adds 1/8" onto the starting diameter of 54mm. Phase 2 was to try making a jig to make a more accurate cut if I wanted 56mm, or whatever diameter I need.
I started with a 4x100 wheel spacer...
Then Mark cut it down to 3/4" thick, bored out the center to 73.1mm, and chamfered the edge....
Now I can bolt the jig to the back of the wheel, insert a standard centering ring of my choice, and guide the router on the ring. I can also use the jig without a ring and cut wheels to accept centering rings. Since I've already cut the wheels to 57mm, I'll try cutting them to 73.1mm and see if the centering rings will go into the wheel directly. I'm not sure how accurately a router bit will transfer the jig diameter to the wheel, but I'll find out next week........Why bother? It's just me experimenting and learning stuff as I go. Worst case is I'll screw up $100 worth of wheels.
