# Homework Help: Stuck With Rudder

1. Feb 16, 2005

### sharans

Iam faced with a problem of controlling the rudder of my
20*30*15 (cm) boat.I need to take the motion for the
rudder from the propeller motion, as a shaft cannot be
incorporated.
By the way,do i need a rudder at all to control
the direction.

ANY RELATED SUGGESTION IS VERY MUCH APPRECIATED.ASDSSDS

2. Feb 16, 2005

### FredGarvin

You're going to have to explain what you are looking for a bit better. I don't understand what you need. You want to use the rotational motion of your propeller's drive shaft to actuate the boat's rudder?

If you have twin propellers, you could get away without having a rudder, but it would not be as effective as a rudder.

3. Feb 17, 2005

### sharans

Hi Fred,
Iam preparing for a competition wherein i need to make this small
boat to reach the given destination in minimum time.
So i need to make it as effective as possible,especially while
encountering U turns.
I wanted to know whether there is any way by which i could
actuate the rudder or go by two propellers.

4. Feb 17, 2005

### FredGarvin

Am I correct in assuming that this would be electric powered? Without knowing any of the constraints or objectives you are dealing with it's tough to come up with a best idea. Will this be radio controlled? What types of maneuvers do you want/need to do?

I don't readily see a way to actuate the rudder off of the driveline to the propeller like you had mentioned (not that would be easy to do that is). The two motors came to mind immediately. You would have to have two motors and be able to vary the speeds of each independently.

If you can provide some more details we could help a bit more.

5. Feb 17, 2005

### brewnog

You say a shaft cannot be incorporated.

Can you elaborate on this please?

Cheers.

6. Feb 17, 2005

### sharans

Basically my challenge is to have the best W/Te ratio for my
boat.
W-weight carried by the boat
Te=Ta+(d1/d2)Ta
Ta-actual time taken to reach the bank
d1-deviation from the destination point
d2-shortest distance between the banks
The boat will be electrically powered.
Actually, i didn't get the idea of using two motors of varying speeds.
Is it for the twin propellers?
Then wouldn't it become less effective without a rudder?
Could u elaborate on this please.
By the way, i was talking of the shaft system commonly used to
move the rudder.
It would be kind of u if u could suggest appropriate material for its
hull.
My ship will be loaded and then i need to take it to my destination.
HOPE TO HEAR SOON FROM U GUYS,THANKS.