January 12, 2004
Snip Snap
Found this on the beach. A crab's claw. Engineering perfection,
it is a fabulous design. The moving claw is hinged around a ball and cup joint on each side of
the claw body. Inside, there's a large fixing point for the muscle. Fascinating!
Notice the ball and cup on the drawing. The fitting is very accurate, the parts look machined or cast rather than grown. The design is nicely optimized. See the muscle attachment points on my drawing left. The close claw attachment point almost twice as wide as the open claw point, allowing for twice the muscle and hence increased strength. In a similar vein, it is more than twice the distance from the pivot, again, the crab needs to be able to close the claw with great strength but only a little effort is needed to open the claw. I wouldn't fancy being nipped by one of these!
Posted by robives at January 12, 2004 05:30 PM