The addition of a Condyloid joint at the base of the finger offers the robot hand similar freedom of movement to a human finger (currently four degrees of freedom).

With the addition of the base, this finger can sit upright and moves very organinically within a similar range to the human finger.

Initially starting with a bowl shape, cut bellow the centre line of the oval to allow for the second degree of freedom, the cup could not be retained without outside force. Also, the joint could bend too far back compared to a human hand.

And so, instead the cut out was changed to a right angle, this both offered more human-like areas of movement but also allowed the joint to be self-retaining.

Due to manufacturing limitations, this new cup required support material on the inside of the cup. This required more clean-up on the part after printing, however, ultimately left no negative effect.

This prototype joint does require some improvments however, The halls of the joint are too thin and the cup started to tare within only an hour of being manipulated and tested.

To solve this, the wall thickness of this part has been increased. From 1mm to 2.5mm. This new version of the part is yet to be printed, however is expected to offer a far stronger joint, and should make it less likely the joint will pop out.