Re: [PSUBS-MAILIST] Fishtail propulsion

["Alan James" <alanjames@xtra.co.nz>]

They're pretty good Jim,

I saw some others when I followed the link. One was hard to tell from the real thing.

Looking at their side to side head movement convinces me that it would be a bad

form of propulsion for a sub as you'd get sick quickly.

Alan

----- Original Message -----

From: JimToddPsub@aol.com

To: personal_submersibles@psubs.org

Sent: Friday, December 03, 2010 3:41 PM

Subject: [PSUBS-MAILIST] Fishtail propulsion

Frank,

 

Here are a few videos I found of mechanical fish such as we were discussing.

 

http://www.youtube.com/watch?v=eO9oseiCTdk&NR=1

 

http://www.youtube.com/watch?v=RFgz2pEimu4&NR=1

 

http://www.youtube.com/watch?v=1QGyxfigkCY&NR=1

 

At some point just for fun, I might build a rig to try out on my canoe or a Jon boat.  From a top view:

B= body of the canoe

P= the powered section moved left and right

F= fin

x= hinges

 

BBBBBBBBBBBBBBBBBBBBBBxPPPPPPxFFFFFFFF

 

When power is applied to P to swing it left and right, F will swing in the opposite direction (by the force of the water) to provide propulsion from the sculling motion.  P will move through fewer degrees of arc than F.  The range of motion for P is determined by the configuration of the push/pull rods which power it.  The range of motion for F is determined by stops on the hinges.

 

I have several other projects with higher priority, but maybe one of these days...

 

Jim