So, you had the two aluminum wheels just lying around? What were they in their previous life. I want to build a 2x72 for shop work and knifemaking. Wheels are expensive!
The large wheel came from a junk shop for $2.00 but it had a U shaped one inch thick rubber glued on that I had a **** of time trying to get off, finally used a band saw to cut it off, then made a shaft on the lathe and turned the rest off. For the smaller pulley I used a hole saw on a piece of two inch aluminum plate and finished on the lathe.