I certainly wouldn't disagree with using metal arms for a milling simpson. I don't see why I'd want to replace the strings, though. 1/8th" dia. braided Spectra speargun line is 1050lb test, and extremely low stretch (parallel core). Very low friction, too, although that might cause some problems. I'll have to think about it, but I'm pretty sure you can make string tensioning work.
edit: Ah, I see, are you suggesting that side to side motion of the line allows a certain amount of flex? That's easily solveable past where it winds up, but I'm not sure how one regularizes the winding... surely there's a way.
edit: Ah, I see, are you suggesting that side to side motion of the line allows a certain amount of flex? That's easily solveable past where it winds up, but I'm not sure how one regularizes the winding... surely there's a way.