John Doe wrote:
I have some hand tools, but no significant shop tools.

A long-standing problem... Sometimes aluminum flat bar is bent
into a U shape so that it can be used as a wheel axle.

One of these would serve as the middle bit of your jig:
http://www.grainger.com/Grainger/hex-standoffs/spacers-and-standoffs/fasteners/ecatalog/N-8niZ1z0o4bfZ1z0o4o3

A welder and hack saw and a piece of flat bar would work well.

--Winston