[QUAD-L] Brace?

[greg]

I'm trying to attach a bracket to my chair. It's made to clamp onto a round tube bar. But I have none in a good area. A long time go I had on a very old chair a tube bar that was like 3 inches long, that had a flat peice on it that screwed onto the chair. That would be perfect. I just need a 2 or 3 inch round tube bar, that has a hole in it to screw on the chair.   Anyone know a site that sells brackets, clamps, etc. for chairs? Also what might help are those rectangle shape nuts that can slide in a groove, then turn so thy can't pull out.   Thanks