[jpetito]

Why not cast them in aluminum and drill/ream the holes? Ditch the bearings as they make the thing over-engineered and heavy.

Requires a bit of machine shop work, but with so much gear on ebay and craigslist, maybe a sponsor would donate cash or equipment. Go to them with a workable plan and lots of shops, because they need these skills, will help you teach and learn the skills.

It's truly the journey and the learning, not the cost.