Centrifugal Arm Claw

[artdutra04]

I wouldn't use servos for this application. If you really want to make a motorized pincher claw, using a Window motor and a potentiometer for angle feedback would be much more preferable. Or if there are only two states needed (such as retracted in the robot OR fully extended), a pneumatic cylinder would be even easier to use if you already committed to having pneumatics on your robot.

As for the claw, is there any compelling reason why you are looking to weld dozens of links of roller chain together? It would be much easier, faster, and significantly lighter just to cut a claw arm out of 1/4" polycarbonate (Lexan) sheet.