I could do it.

I don't think I have the capital investments to buy parts en masse however.

They aren't delrin bearings, they are self-contained steel ones... I know I know what you're gonna say... "WHAT ABOUT THE SAND!?!?"

These bearings run about $10 a set and are sealed much in the way that rollerblade bearings are. They last a long time and aren't all that difficult to clean

of course, I could make delrin bearings for them, at work, we have barrels upon barrels of delrin "beads", fabbing a hub, runners and the bearings themselves however would be a chore, and costly.