My 1st set of big wheels were a bit rough around the edges so I figured I would have a crack at another set using the ideas I like from both Paul and Chook's methods.
Having just recieved a lovely pair of 80mm fat bike rims all the way from china here's what I have done with them.

Hope this helps.

Part 1: Make forms, jigs and hubs.

A, Home made guide for routing circles


Glass cutting template, bout 10mm larger than the overall rim diameter.



B, Centering jig, I cut this 5mm oversize then spun it and sanded the edge down to get an exact fit this is critical to get your rim centred on the form in relation to the hub. (Failing to do this properly last time is where I think most of my problems came from)

Mark the outside edge of the rim on the form base. Form base should be cut to about 60mm larger than the rim dia.
With the rim stil in place dril and set some steel rods as guides. Take care to set them hard against the rim.



C, Form base with rim positioning guides



Rim on base



D, Make hubs and bearing spacers. I used 48mm OD alluminium scafold tube and 6004 bearings. The hub is 20mm wider than the rim and will protrude past the disk on one side of the finished wheel.



E, Nylon hub blank on form base. I wrapped the nylon with a layer of duct tape because I made the about 1mm to thin. (still learning to use a lathe properly)