Summary

This is an addition to the awesome little flexible hand designed by Open Bionics. It allows the hand to be opened and closed with a 9g servo.

See it in action : https://www.youtube.com/watch?v=PqYdbSWjsZ0

No changes in the original hand model have been made.

The attachment should be printed from PLA and secured to the hand with glue.

The servo's rotational motion is converted to linear motion by the rod. It should be printed flat for maximum strength. The rod can be fastened to the servo with the included servo horn. The ideal distance from the center of rotation is 10-15 mm.

Metal gear servo is required.

All the parts have to be glued together first. Then when the glue has cured, the servo horn should be fitted in and the screwed in place. The screws can be accessed through the holes in th wrist model.

If the hand does not open fully because the TPU isn't flexible enough, or the servo does not have enough torque, we can use a few tricks to help it. We can stretch the hand to loosen up the joints, so that less force is required to overcome the springiness. We can also make a few cuts on the side of the thumb (marked with arrows) to make it less stiff.