Many hands make light work

As we approach the deadline for the second trip to Haiti, things are really starting to come together. The socket and forearm are just about done and only need some minor adjustments. Besides the overall fit of the socket, two of the major problems that we wanted to fix were the length and angle the arm. The length needed to be decreased and the angle needed to be brought more towards the body. After some adjustments to the location of the screw holes, we are pretty confident that these problems are solved. Moreover, we decided to add an additional screw hole to both pieces so that we have two options for the angle, depending on how the screws are placed. The two pictures below show these options.

The most recent modification involved adapting the location of the screw holes in order to embed the screw heads beneath the inner surface of the socket. This design will enhance the integrity of the connection and make the bottom of the socket more comfortable by moving the hardware out of the way. Once this is finalized, we are ready to print the final arm and various extra pieces in skin-colored filament.

Get a grip

The final hand is also just about completed. In order to further increase the grip capabilities of the hand some sticky grip material was added on the inside of the thumb. This should prevent larger objects from slipping once grabbed. The material we will be using for the final arm has arrived as well, and as a test we printed the final hand design out with it.

Buckle up kids

This week we solidified the design for the detachable piece between the harness and socket.The black webbing in a V-shape provides integrity to the apparatus by combining a high strength, durable material with a configuration that adequately distributes the weight of the arm. The bottom two straps will be adjustable using simple rectangular buckles, and the top two straps will be sewn onto the harness once we fit it to Chris.

Lastly, we adapted the design for the straps on the socket itself. In order to provide a user-friendly and effective fastening system, we decided to affix elastic straps to one side of the socket, with Velcro patches on the bottom that attach to the other side. In this way, we can still use the elastic to provide a compressive force that helps stabilize the socket, while allowing Chris to adjust the fit with his other hand.