« Last post by cyberjeff on July 29, 2015, 07:41:14 AM »
I think both of those suggestions have HUGE merit and are very exciting possibilities. I thank you both for bringing them up! This vacuum neoprene idea and the Nitrinol wire idea have my attention. Maybe one of them can be a plan b? I'm already all in with my existing servomotor and pulley system plan having already bought a lot of what I need, already tested and done proof of concept, etc. If you brought this up a year ago I might try it, however, I have to at least give the way I have been planning for over a year a try before trying anything else ya know? I don't see why the way I am planning wont work. Also, I agree it will be WEAK. I can upgrade to more powerful higher voltage motors later though if I get more $.
One of my concerns with Nitrinol which I have looked into in the past is I haven't seen many projects using it and it isn't widely available from what I've seen. It is very experimental and expensive and could have a lot of complications in terms of heat and electrocution possibilities... hmmm...
If you have proof of concept then you should run with it. The muscle wire is expensive and I think may be too slow and energy inefficient. The vacuum idea would require building things that are not off the shelf that have never been done. The advantage that air, or vacuum has is that it has energy storage, you can get a huge jolt of power and then wait for recovery. In my mind this is similar to the way most people use muscles.
I have given some thought to your idea of bands and servos, not that I wish to copy your project, but rather use it for a flexible spine. The bands would run through the spine and then outside where they would be tugged on by servos. Assuming the spine returns to a straight position, the curve of the spine with one servo could be modeled on a quadratic bezier. I would need 3 servos.
Since you have no flesh your robot could be relatively light, reducing forces needed. I think you may need to compromise between speed and servo size or by setting your pulleys as a force multiplier, probably you have already done that.
What are you casting with? How is the weight?
I'm making my simple little toy out of cypress and find the skeleton weighs a small fraction of the total. I suspect you may have substantial weight.
Good luck to you and we await to see your progress!