what Chain size and tensioner to use for the drivetrain

[Dick Linn]

HDPE is readily available in cutting boards, laundry detergent bottles and other things marked with the #2 recycling symbol with the HDPE or PE-HD printed below the triangle. Think milk jugs, eh?

If you keep your chain runs short, use quality components and align them and occasionally lubricate the chain, you shouldn't have a lot of chain tensioning problems. I agree that if your design allows the primary drive/gearbox to be adjusted or shimmed slightly, it makes life simple. One time, we needed a tensioner for a long chain run, so we cut a guide groove in some skateboard wheels and used them as rollers. Worked marvelously, and cost virtually nothing. The only other time, we stuffed a narrow piece of HDPE into a channel in some 80/20, as the chain needed to go over a rather misplaced structural rail in its path. frtgtgf'ikb n

(The last comment is from our kitten, who jumped up on the laptop twice and managed to shut everything down a few minutes ago. Thank goodness Firefox cached everything... I wouldn't want to deprive y'all of these words of wisdom amongst the cussing...)