The Rollpaw Gripper Kit for Rollarm Robotic Arm is a simple solution for projects that need small grippers. It is driven by two 9g SunFounder servos: one to control the jaws to open and close, and the other to control the rotating of the paw. When the jaws is fully stretched, the maximum distance is 60mm, which means it can grip an object with a 60-mm diameter.
The joints of the two jaws are all connected with self-locking nuts, so that they would not fall off easily during the rotating and keep the paw "safe and sound". The Rollpaw is easy to assemble and use with the code provided. Just try it!