[ratdude747]

Originally Posted by Joe Johnson

I love ABS sprockets. The hold up nicely if you can follow the rules.
#1 keep the chain tight (preferably by having a good chain tensioning system designed in from the start)
#2 keep the sprockets and chain aligned and in one plane
#3 all torque transfer sprockets have over 120 degrees of wrap.

If you break these rules and the chain jumps, ABS is going to get munched much more than aluminum but that's the way the cookie crumbles.

For #25 chain:
I typically use 1/8 ABS sheet with bevelled edges for the teeth and make a sandwich with 1/8 sheets on the sides. ABS solvent bonding glue is your friend (and amazing).

For #35 chain:
You can use the above technique or you can make a one piece no glue design by using 1/4 ABS sheet but you need to really bevel the edges. If you have a belt sander and patience it isn't too hard. Makes a mess but the results are nice.

As always, YMMV

Good luck

Dr. Joe J

Idea: if one has engine lathe access, use the lathe to bevel the gears. That should result in pretty, even gears.