torque roll

[Priorty1]

Everyone has been a big help so far. So let me pose another question.
I was told that all Gear to Gear reduction units change the rotation of the motor from counter clockwise to clockwise, and a Belt Drive reduction unit does not. I was also told that a Gear to Gear set up would be more likely to cause torque roll. Here's the question: a motor turns counter clockwise a belt reduction unit turns counter clockwise thus the prop will also turn counter clockwise wouldn't this set up be more likely to cause torque roll. My thought is with the motor turning counter clockwise and the Gear to Gear changing the direction of the prop to clockwise that the two would cancel each other out or close to it.
Thanks all

 

[Waterthunder]

You have that backwards the belt is the worst case scenario with the most torque roll the gearbox is about half as much. There are allot of physics involved however due to the torque multiplication of a gearbox the prop still causes more torque roll than the motor but if the prop and motor torque in the same direction AKA (belt drive) you will get an extreme amount of roll. The other major player is weight the heavier a boat is the more it will torque roll because just like water and electricity thrust energy will take the least path of resistance and it is easier to torque roll a heavy boat than it is to push it forward so the worst case is a belt drive turning in the same direction as the motor and then add the massive weight of one with all the energy rolling in the same direction you have a rolling log. A gear reduction and a direct drive will roll much less than a belt drive.

 

[Waterthunder]

P.S. a gear to gear gearbox doesn't change direction of the motors rotation it changes the props direction of rotation.

 

[Priorty1]

Thanks Waterthunder.
that was my thoughts " that the belt driven unit would be worse", I didn't think about the multiplication of torque coming from the box or the fact that it's over a surface area of say 78 -80 inches (prop circumference) as opposed to the diameter of a fly wheel say 18 inches in diameter (just a guess). Ps: I know that the gear boxes don't change the rotation of the motor " that would be a neat trick, though".

 

[SwampMatt]

cool.

 

[jim]

Matt,

The max torque roll would theoretically occur at the rpm where the motor produces the most torque, does that make sense? The prop reacts the torque to the boat through the motor mounts.

If you "feather" the prop, which is the airplane term for the maximum pitch you described it will just stop the engine, or possibly slow it way down. On an airplane it will stop it. Been there done that.

Jim

 

[basketcase0302]

Priority1,

Waterthunder and Jim's right as usual!
Almost sunk my new Diamondback first trip out while making a tight turn in deep water! Long belt with almost full throttle to spin it around fast scared the piss out of me! (Only once)!

Case cured...Counter rotator with no torque roll at all now.

Basketcase

 

[jim]

Basket,

Do you notice any torque now while the engine is spinning up?

Jim

 

[c chardt]

Boy it was hard to get use to going from driect drive to putting a rotator the torque from one driection to the other it takes getting use to. and there is about 3 times the torque roll

 

[Anonymous]

Thunder, did you just call my old barge a "rolling log"?
It can be, but I just thought it was the driver ..... :lol:

K.

 

[Waterthunder]

No offense intended just wanted to convey the differences. Do you run a belt drive? Each combination has its strong points and it's weaknesses. Hey CC wait until you run a small hull with a belt drive things get real touchy then even worse than a DD car motor.

 

[basketcase0302]

Jim,

I can not notice any roll at all, (in the water or on the trailer). In the water it just launches. Usta' have to have a gorilla arm to aim the boat straight when up on a plane for a while with the 3 blade Powershift. Now you can steer with 2 fingers if ya' wanted to, (more fingers to fumble around for stuff like I'm always doin)!

Basketcase

 

[jim]

That's funny,

I'm glad you have good performance now.

Jim