[EricH]

Originally Posted by AdamHeard

I have used 60T #35 Aluminum sprockets on extremely high powered and high reduction arms (As in the final stage of a 2500:1 reduction directly attached to about a 5' arm that was rather heavy [forgot specifics] and held the trackball at the end of that. It also hit the rack when extended at drive speed many times) with no signs of fatigue or tooth wear. I believe this is true of 330 as well.

True. 330's are custom-made; I don't know the metal. See also 330 2005 and 2007.

We also used some mid-size ones in 2007 for deploying ramps. Those took everything we threw at them and still worked. They were on the outside rear of the robot, virtually unshielded, IIRC.

Aluminum sprockets are a good thing if you use them correctly, in any application. The trick is to use them correctly. (I know 330 has used them in drivetrains and arms for some time. Other things, like tires, have or worn, but not the sprockets.)