Continued - Part 2: The Hands of Deft

Here is a close up of the mounting brackets, Hurst motor and motor cover for the mechanical hands. The motor is a HURST 60 rpm geared motor purchased for about $35. The motor cover was made from scrap aluminum sheeting. This cover protected the cheesecloth from the heat of the motor. The mounting brackets were made from various sizes of aluminum stock I" and smaller.

These pictures show the top portion of the hands. The idea originated from Allen's Halloween home page, where he had made a skeleton puppet hand. I modified it to include a motor and crank mechanism. The concept is quite simple; a 12 lb. fishing line runs across the top of each finger to the tips and tied. The other end of the line is connected to a spring and secured to a screw eye. This returns the finger to the up position. A second piece of line runs from the bottom of each finger to the crank mechanism. By staggering the strings, you can get the fingers to move at different intervals.

[See diagrams below for more clarification. Note that, as this is a Pepper's Ghost effect, the black parts of the hands are invisible to the spectators. The shiny metal parts are covered by the figure's shroud. -DF]

The crank was made from aluminum stock; holes were drilled to accept the crank and motor shaft. An additional hole was drilled perpendicular to the shaft hole and tapped to accept a 10/32 screw. This was installed to lock the shaft to the crank. The crank is a control wheel from a radio control servo. This part is available at most hobby stores.

The fingers were made from dowels carved using a rasp file. I highly recommend using the rasp; it made a difficult job easy. The jagged effect left by the file was a nice addition to the look. The hinges for the fingers are mini control linkages used in radio controlled planes. The thumb has a home made spring for the knuckle. I think I will modify this next year I didn't care for the movement.

The extra weight produced by the hands required the addition of 2 springs at the shoulder assembly. This may vary depending on how far the hands are positioned from the body.

The Bottom view of the right hand. Here you can see the detail of the control mechanism and routing of the fishing line. This hand used screw eyes for guiding the line. The right hand was modified slightly and the screw eyes were eliminated.
Close up of the completed left hand.

[The Baron's opinion of our close scrutiny seems clear.]
Onward to part 3...

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