Re: Thruster Steering

[Dave Everett <deverett@idx.com.au>]

At 13:00 25-06-98 PDT, you wrote:
>Hi guys,
>            I had an idea for my steering system.  If I had a thruster 
>on both sides of the sub, I could steer it by simply turning one on or 
>the other.  For example,  when I turn only the left one on, Iwould turn 
>right.  Or if I turned the left one on forward and the right one on 
>reverse, Iwould make a sharp right.  Both forward I would go straight.  
>Has anyone tried this, or do you have any input as to pros and cons of 
>this idea?
>
It's a perfectly sound idea. This is how I am going to steer an amphibious
all-terrain vehicle I am building (when it's in the water). Pulse-width
modulating the motors will give me very good control over direction.

The only other thing you need to do is have the motors contra-rotate,
otherwise your sub will crabtrack underwater instead of travelling straight. 

Contra-rotation means, for forward travel, one motor turns clockwise while
the other turns counter-clockwise. If both motors are turning the same way,
the craft will tend to twist in the direction of motion.

Dave Everett.