Re: [PSUBS-MAILIST] Unusual propulsion system

[Jon Hylands <hylands@ibm.net>]

On Sun, 20 Aug 2000 01:36:40 EDT, TeslaTony@aol.com wrote:

> I don't know where you got your information since the specs I have say it can 
> contract in as little as 4 milliseconds (it's better to do it slower though) 

Yeah, if you do it over two seconds, the muscle wire last forever. If you
do it in milliseconds, the life-cycle is very short.

> and relax (a more descriptive word than "expand") in the same amount of time 
> it takes to cool down.

In ambient temperature, it takes about 12 seconds to cool down...

>  There are several factors that can control the speed at which the wires 
> expand and contract:

Yes, it depends on a bunch of stuff. The point I was trying to make is that
I think muscle wires would be a bad choice for building a "fish" propulsion
system. If you can figure out a way to do it, I'd love to hear about it,
because I'd love to build a very small fish AUV with the stuff.

Here's some info from the RobotStore.com website, about the "pistons" they
made with the stuff:

ELECTRICAL 
           Total electrical resistance: 0.2 ohm 
           Typical power: 5 Amps at 1 Volt 
           Typical contract time: 2 seconds 
           Typical relax time: 12 seconds 
           Typical cycle rate: 4 cycles per minute 

And that gives you a stroke of a little under one inch...

Later,
Jon

--------------------------------------------------------------
   Jon Hylands      Jon@huv.com      http://www.huv.com/jon

  Project: Micro Seeker (Micro Autonomous Underwater Vehicle)
           http://www.huv.com