Torque Roll

A general, non-powerplant specific, discussion on airboat technology, ie., hulls, rigging, polymer, etc..
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Swampsaver
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Torque Roll

Post by Swampsaver » Tue Mar 03, 2009 9:26 pm

Can anyone explain torque roll in a quick easy way. I have reviewed several past posts and just can not figure out a way to explain it to non airboaters. I'm sure some of our experienced members can do it in simple terms.

Thanks,

Swampsaver.

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SwampMatt
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Re: Torque Roll

Post by SwampMatt » Tue Mar 03, 2009 9:31 pm

Easy. FOR EVERY ACTION THERE IS AN EQUAL AND OPPOSITE REACTION.

So when your motor spins your prop one way, it also tries to spin/roll the boat the other way.

It don't get more simple than that! :D

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Whitebear
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Re: Torque Roll

Post by Whitebear » Tue Mar 03, 2009 9:35 pm

Its basic for every action there is an equal and opposite reaction. Remember old science class in school? When you spin up ethe mass of the prop and motor the hull has to resist the spin in the water. Since water is a liquid the hull will roll to the opposite side from the prop spin up. It can VERY pronounced or bearly perceptable depending upon several things. Prop length and bite, hull width and chine design as well as overall weight, prop and engine acceleration as well.

Know how if ya put your hand on the fender of a car and stomp the gas you can feel the car rock? Thats exactly whats happening in the boat, except the car is on wheels and the boat is in the water and moves in the water.

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bravo1218
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Re: Torque Roll

Post by bravo1218 » Tue Mar 03, 2009 9:40 pm

There was a video of waterthunders boat torque rolling here a few months ago that I have been looking for. A picture is worth a thousand words and will explain it fully. Hopefully someone can repost it.
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SwampMatt
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Re: Torque Roll

Post by SwampMatt » Tue Mar 03, 2009 9:42 pm

Oh yeah, the motor.

The motor has parts that are spinning also, (not just the prop) so there is some torque roll for that too. But I think most of the "torque roll effect" we see in airboats comes from the spinning mass of the prop.

If a boat is direct drive, then the torque roll is the total of the prop and motor (since they are both spinning in the same direction)
Same with a belt drive.
BUT, with a (normal) GEAR drive, the motor and prop spin in opposite directions - so you get less torque roll because the torque roll from the motor CANCELS OUT a little bit of the torque roll from the prop.

You've got some inquisitive non-airboating friends!!! LOL Hats off to you for educating the non-airboating world out there.

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Whitebear
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Re: Torque Roll

Post by Whitebear » Tue Mar 03, 2009 10:16 pm

Can anyone explain torque roll in a quick easy way.

I fear we have WAY overdone it. Sorry about that :)

Scotty
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JOLLY ROGER
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Re: Torque Roll

Post by JOLLY ROGER » Tue Mar 03, 2009 10:26 pm

Prop and boat playing Tug of War, Boat is winning barely. :lol:
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Waterthunder
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Re: Torque Roll

Post by Waterthunder » Tue Mar 03, 2009 11:49 pm

Simple physics just as with everything else water, electricity and fluids. Everything always takes the least path of resistance if it’s easier to roll a boat on it’s side then it is to go forward it will roll till the point it’s easier to go forward. Torque roll is a challenge to manage or overcome!
THE PROOF IS IN THE PROP!

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airduds
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Re: Torque Roll

Post by airduds » Wed Mar 04, 2009 7:28 am

Think what a conventional helicopter would do without a tail-rotor
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SwampMatt
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Re: Torque Roll

Post by SwampMatt » Wed Mar 04, 2009 9:28 am

And if you wanted to do the math, it's probably the good ol' f=ma equation Force = Mass x Acceleration

but it don't get much more simple than: for every action there is an equal and opposite reaction.

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bondsman
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Re: Torque Roll

Post by bondsman » Wed Mar 04, 2009 10:27 am

here is a pic of torque roll.

Image


Image
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Swampsaver
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Re: Torque Roll

Post by Swampsaver » Wed Mar 04, 2009 8:22 pm

Thanks to all of you. I have some good answers now.

SS

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Waterthunder
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Re: Torque Roll

Post by Waterthunder » Thu Mar 05, 2009 7:21 am

Here is a boat that has a slight torque roll problem!

Image
THE PROOF IS IN THE PROP!

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JAYBIRD
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Re: Torque Roll

Post by JAYBIRD » Thu Mar 05, 2009 9:47 am

slight ! :lol: :lol: :lol: :lol: :shock:
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MYDIXIEWRECKED
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Re: Torque Roll

Post by MYDIXIEWRECKED » Thu Mar 05, 2009 9:50 am

Dave, you ought to install a self leveling seat system for Jimmy! then he could ride it out! :shock: :lol:
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