Wednesday, February 18, 2015

sorting through an explosion of plastic stuff...

Yesterday I was looking at the bag of 3-D printed plastic parts that will be chipped apart and assembled into a sample prosthetic hand. The fingers and wrist of this design are connected through a set of strings, that are pulled tight when the wrist is bent. The tension on the strings pulls the fingers and thumb into a closed position. These raptor hands are not the best hands one can imagine, but they are colorful and cool, and represent the best of intentions applied to solving a societal situation of need. The movement to make these hands deserves the applause of single hands clapping. (my reference to Zen)

In the woodshop, we've had all kinds of experience tying knots in string, and it's a thing my students often ask me to do for them. From shoe laces, to button toys and puppets, knots present challenges for young fingers. Then getting knots positioned in just the right spot to control the length of a cord can be an even greater challenge.

The raptor hand uses knots and screws to tension the fingers, and I wondered as I watched a connector box being printed, whether there might be a simpler approach using cable ties. A simple zip strip could be pulled to tighten a cord one handed, and could be easily fixed, and adjusted when the cord is stretched. I made the proposal to the enable development community and learned that the idea had already been proposed by a member but was still in the development stage. The cable tie approach offers the potential of easier and quicker assembly and adjustment, even for the one-handed, and may be mounted without screws at a lower profile.

What you see in the image above is my version of a simple zip together connector for cords on a 3-D printed prosthetic hand. I attempted to print it in two scales, being uncertain whether the resolution of the MakerBot can handle the 5 mm. size. My print job was an utter failure. No, it was a fiasco. The printer will not print at a high enough resolution to print what you can by at Walmart, one hundred for 2.97.

I can understand why the younger set is fascinated by 3-D printing. It is interesting watching it work. But we also need to keep in mind that the world is already overflowing with plastic junk. If we realize that in making things, we are in actuality making ourselves, then we must show ourselves as being responsible for the future of the planet. That means, essentially, using our varied crafts to aspire to the greatest heights of service and quality we can imagine.

Yesterday on the news I watched an interview with a man who hopes to travel to Mars as an astronaut, leaving his wife and young son behind, even though he knows he will die in space or on Mars. There are no provisions made for return. Think of life here as being like that. Select for nobility in the developmental adventures you choose for yourself. With woodworking and other crafts, and in sharing what you learn with others, you may not need to die in space in order to find fulfillment.

Make, fix and create...

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