Little Finger

Little Finger

Each finger consists of 

• three pieces of 3mm flat Aluminium bar, cut, drilled, tapped and filed into shape
• one piece of 0.5mm Aluminium sheet cut, drilled and folded into shape
• two pieces of 2mm Aluminium tube drilled and tapped
• two 5x2x2 bearings
• two M2 washers
• six M1.5 countersunk bolts
• one M2 socket head bolts
• Elastic cord
• Multifilament fishing line

The Arm

Mini Robot Arm

Adding a wrist and an elbow to the Mini Robot Hand using 2 more TGY-306G-HV servos.

Servo Horns are replaced with integrated Aluminium clamps. It cuts down on the part count.

Grasping the Pencil is easy. Getting the timing right to throw takes a lot of practice (I'm using a RC Transmitter). Now for some precise micro-controller timing.

The hand

Mini Robot Hand

Open hand

Closed hand

 Hand on Hand

The hand is all metal and is fully ball raced. A single RC servo controls the hand's functions. Clockwise rotation closes the four fingers. Anti-clockwise rotation pulls in the thumb and closes the whole hand. The hand is made mostly of Aluminium with some brass tubing. Multifilament is used for the tendons.
A figure 8 pulley system wraps around the bearings, links the two joints for each finger.
The 12 bearings are 5x2x2mm
The servo is Turnigy TGY-306G-HV. Servo range extended to about 200degrees by adding 1K resistors on either side of the servo potentiometer
Size: 77mm long, 34mm wide (excluding thumb), 15mm high - Finger length 30mm

Operating the hand

Grasping a AA battery