A little over a year ago I had a semi-gruesome accident; I stepped off of a ladder and I caught my wedding ring on a nail head. It literally stripped the finger off the bone. This was in spite of me being a safety-freak and having lived a whole second life doing emergency medicine and working in trauma centers and the like. I do have trauma center mentality which means, among other things, that I know you can’t wind the clock back. A few seconds make an incredible differences in people’s lives. Knowing that it couldn’t be undone, I stayed relaxed and in the end I have to say I had a good time that day as I worked my way through the system (I ended up in a Philadelphia trauma center with a nearby hand specialist) as I was usually the funniest guy in the room. Truth be told they ask incredibly straight questions like”are you right handed?” “Well I am NOW”.
So now I could really use a bit of a body hack, having seen the X-Finger on Hackaday long before I knew that I would one day work with them, I was hoping that we could get one to work for me. In speaking with a couple of the mechanical engineers on the Hackaday staff we decided to get [James Hobson] and [Rich Bremer] involved and that the best way to do it was to get a casting of my injured hand out to them.
So here is a video of me making a cast.
Starting with casting alginate I mixed it 1:1.5 by volume with warm tap water and mixed. I had a backup amount ready to go in case I ran short, which it turned out that I did indeed need. Since one hand was now ensconced in gooey mold making stuff I had to use a drill with stirring rod to quickly mix up the rest.
The alginate sets within 12-15 minutes and because it has a little “give” to it I was able to squeeze my hand out without damaging the mold.
Next a mix of casting plaster is made per the instructions and poured in being careful not to trap bubbles.
Cutting out the casted hand was a matter of a single edge razor blade and the cast was complete and ready to be shipped to the mechanical guys.
With the hand cast is on its way to [James Hobson] for his evaluation with an eye towards mechanical design, look for a followup Part II post of his initial assessment of my hand sans finger. We have discussed making the mechanical finger replacement a Hackaday project and getting input from viewers at large. Are any of you interested in taking part in the process? If so please leave a comment below.