Greetings Folks,
I'm a living historian (F&I War, RevWar, 1812, and 1830's.) I volunteer at an historic village in NJ (blacksmith, militia, and leathershop). I am the only volunteer who has done any leatherwork. We have a new 16 year old volunteer who was born without most of his right forearm. He is currently interpreting the Carpenter Shop, and wants to be able to do more. We thought that it would be nice to try and fabricate a prosthetic arm which would fit in the period (1836) and would have the ability to hold a chisel securely so that this young lad can work - in "period."
The lad's upper arm is a bit more slender than usual, and his forearm terminates about 3 inches from the crease of his elbow. His forearm is tapered/conical in shape, and it is therefore necessary to secure the appendage to some sort of cuff which is attached to the upper arm. At the end of the forearm I have designed what will be a relatively lightweight "hand" that uses a strap-clamp like mechanism to secure a chisel or similar tool. My concern is that even though the hand is not heavy, striking the chisel with a mallet could cause the forearm portion to move out of place. I have attached my preliminary sketch (since this sketch, I have revised the tool-clamping device.)
So, the advice I'm looking for has to do with ensuring the stability of the forearm prosthetic under semi-strenuous conditions.
I would be very grateful for any ideas or advice in this regard. I figured that harness-makers would likely be the most knowledgeable.
Thank you, and may God bless.