[modelman]

Pricer-this is a unique idea for tumblers but I don't think it would work cast from resin because of the size of your round bars. They probably would break. I cast some track pads from epoxy resin mixed with a hi-density filler and it worked great. A cast tumbler might work if you re-design. Maybe use a double tumbler but make two separate drive dogs where each one would engage a tumbler. Just my opinion. Jim made an important point about the hinges. You learn a lot after you try something and that makes it all worthwhile.