I designed this grip assist to help someone with limited strength to hold a fishing rod. I created this in TinkerCad. This design is a work in progress.  

I used toothpicks and a drop of hot glue for each hinge. 

The design is only partially finished. It still needs some mechanism for feeding the drawstrings across the palm. 

When printing I recommend sizing each finger segment a couple of mm larger than the biggest joint it will need to go past. That seemed to be the most comfortable. 

My Logic:

I saw some designs that had the mechanism to open and close the hand on the exterior of the hand. 

Those were too complex for me and my prints lacked the strength that I was hoping for so I designed this. 

Originally, I envisioned this to be integrated into a glove so the drawstrings could be routed through the palm of the glove. 

Some other changes from the original concept are:

1 Removed the frame from the middle and pinky fingers due to space limitations. I hope to design a fingertip for both fingers that will allow them to attach to the adjacent fingers.

2 Added a split on the inside of each finger to allow each segment to flex and make it more comfortable. 

3 Slimmed down the walls of each segment to about a quarter of its original thickness. The thickness was needed for strength, but it was too much to fit between the fingers. I am experimenting with adding a coat of sealant on the outside to make up for the loss of strength. The best I have found so far is to add a layer of cyanoacrylate just around the hinges. 

This design was created for Abilities In Motion in Reading Pennsylvania. For more information about our 3d printing program please check out or website at www.abilitiesinmotion.org.

This is not a medical device.