constant torque spring motor 2

[allenlr]

I am trying to develop a constant force spring motor with a gear and governor system that will power a small plastic boat about 20 inches long. The boat doesnt need to go fast-slow is great but it needs to run for an hour and a half to two hours on one duration. Has anyone seen such a motor or know of a way to solve the problem? Thanks, Allen

 

[israelkk]

How much is the drag force that the water and air operate on the boat?

How much is the distance the boat will travel during the duration?

The answer to both question will give the required work/energy.

Only then we can see if such a spring exists.

 

[insideman]

Look up "negator".
like a clock spring but constant torque.

 

[metman]

Another example of negator spring is a common steel tape measure.

If you answer israelkk's questions, you might get some help.

 

[unclesyd]

I don't know if these will work but the are very inexpensive and have plenty of stored energy. They ru about as long as any spring motor i've seen.

http://www.amazon.com/Darda-USA-11713-Standard-Replacement/dp/B000IMPEHY

Here is the Darda Website but is a little rough to navigate. Look for repalcement motors in the lower right corner.

http://darda.com/

I think you will have use an electric motor like is in the newer small model helicopters. Use the motor with a higher capacity battery.

 

[unclesyd]

If you can go the electric motor route the new ads for the little RC Helicopter say that the new motor and battery will keep it aloft for 5 minutes. This is turning 2 rotors and gears.