Friday, April 25, 2014

evan's hand: brass pivot bushings

I'm trying to wrap Evan's hand up so I can start assembling Weston's hand asap. I made good progress today. I decided to turn down some brass so I could make some brass bushings for the proximal phalanges where they attach to the palm. I am still using the printed Talon pins though at the top joint. Since Evan's hand is a bit larger, I had plenty or room to drill the holes out a bit larger and then press the bushings in. I also turned down the heads on some Chicago screws so I could get a lower profile look. I also shortened them and made a joint that occurs at the middle palm knuckle as I didn't have long enough Chicago screws for the scale of Evan's hand. I simply center drilled, drilled, and threaded the ends with the 8-32 threads and then used some lock-tight to lock a short section of threaded rod into one half of the pin. The other half then threads onto the this. It allows for no flat screwdriver head showing on either side of the hand (just a side effect from me making this longer pivot pin); super clean. While I was at it, I polished the modified Chicago pivot pin so I would get smooth movement against the brass bushing. I knotted and ran the cables and now I'm ready to string the gauntlet. I'll have to get some hardware for the thumb pivot, as I didn't have anything at home tonight other than a metric cap head bolt. It was a good "stand-in" so I could test the action. The bushings seem to make a big difference in the actuation of the fingers. I really want to try adding the bushings to the top of the joint (and use Chicago hardware for the pivot), but that will have to wait for another hand. I need to get this out to Evan as soon as possible. I'll try to finish it up this weekend so I can get it to him this week.

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