Progress report - Giant Praying Mantis
Progress report - Giant Praying Mantis
I’ve moved forward a bit on the Praying Mantis project since my last post. Having satisfied myself that the design/concept behind the pincer arms was sound I moved on to the challenge of the wings. I knew that I intended to use a street lamp cover as the wings but had not decided if it was necessary (or feasible) to include mechanical movement. I tossed the options around in my head until I came across this little gem:
Saturday, April 4, 2009
While the machine is in motion it is kind of beautiful, but the look of all that plastic sort of conflicted with the rest of the piece, so I cut up a coffee bean scoop to make a cover for the motor.
It is the “kneading” mechanism from a high-end massage chair that I found at the dump a while back. It used to travel along a track, but due to a failed limit switch had stripped its gears. This had no effect however on the mechanism itself that moves in a gentle elliptical pattern.
Above are some before and after images of the street lamp transitioning into wings. After some rather confounding false starts I was able to mount them to the mechanism and run a test to see if the motor was strong enough to support the weight. See the result in the video below.
The test worked out much better than I had expected and confirmed that I would need to figure a way to mount the whole assembly and commit to the idea of wing motion. My only real hesitation at this point was that it meant torching a messy hole in the otherwise smooth surface of the body.
After some trepidation I found the nerve to punch another hole in the gas tank / body. I found that I had to machine another block of aluminum to mount the motor to so as to avoid welding on the mechanism itself. This would also allow me to remove the assembly whole if it ever needed servicing or tweaking.
After a good deal of coaxing, I managed to isolate the parts that I could use, strip away the excess and mount it all on an aluminum block that could somehow later be attached to the Mantis (assuming it could be made to function for the wings).
There was also a rather dark moment where I realized that the position in which I mounted the wings to test them was 180 degrees the opposite of what would work in relationship to the sculpture. Fortunately this only meant re-building the connections between the wings and the motor, and not the motor to the sculpture. Roughly a day lost, but well worth the result in the long run.