pic: Off Season CAD Practice

[GeeTwo]

Originally Posted by Chris is me

There are legitimate arguments against a roller claw in 2011, particularly for long-arm robots. A proper pinch claw can easily weigh just 2ish pounds, when a roller claw needs at minimum 1 gearbox + motor (usually 2), four shafts / pulleys, etc.

An alternative to the roller claw for "rotating the game piece" purpose is to actuate the two halves of the claw independently around the same axis. Then, by rotating them in the same direction, the orientation of the game piece moves without the claw having to slip against the game piece. As I mentioned before, these can be driven from a motor mounted near the shoulder with a belt or linkage rather than out at the end of the arm. I made a smaller version of this a while back using servos whose axles faced into each other. I haven't run the numbers, but I believe that you could get enough torque to hold up an inner tube with the larger FRC-legal servos, but it wouldn't be very robust against defense.