Prop Rotation and Spin-out in the Turns. Oval racing / Running.

[photohoward1]

OK guys as you know I am not a big fan of straight line racing. Just not interesting to me. I like to go fast in circles. I have a large 10's cat... 50", Big Lehner and a x470/3 prop. 70mph in race trim Oval. As we all know the prop spins counter clockwise
and has a tendency to pull the butt end to the outside. (prop walk). My issue is the boat has the tendency to randomly spin in the corners as the nose come down. I know the prop has to contribute to the spin. It's pulling the butt end in that direction. (My R42 has no tendency like that at all.) So my question: *** If I use an opposite rotation prop that pulls the butt end in the other direction, will it eliminate the random spin? ****yes its 16* outside today and I'm over thinking it.

[dasboata]

OK guys as you know I am not a big fan of straight line racing. Just not interesting to me. I like to go fast in circles. I have a large 10's cat... 50", Big Lehner and a x470/3 prop. 70mph in race trim Oval. As we all know the prop spins counter clockwise
and has a tendency to pull the butt end to the outside. (prop walk). My issue is the boat has the tendency to randomly spin in the corners as the nose come down. I know the prop has to contribute to the spin. It's pulling the butt end in that direction. (My R42 has no tendency like that at all.) So my question: *** If I use an opposite rotation prop that pulls the butt end in the other direction, will it eliminate the random spin? ****yes its 16* outside today and I'm over thinking it.

Howard is the rudder long enough ? 1-1/2" below the prop tip about ?? tilting the rudder back will help the stuffing in the turns,, but sounds like you might be giving the boat right causing the boat to lift the rear putting the bow in & causing it to hook ???

[jingalls007]

Are you running a skeg strut?

[photohoward1]

Was thinking a bigger or longer rudder might help. One of the problems is when you turn the bow plants more than say an R42 and swings the back around. Prop walk can't be helping.

[photohoward1]

Yes. But the prop sits pretty high so almost not even in the water.

[jaike5]

In my Insane G3 44" big Lehner, skeg , 2515 17 45 . no spins. Can you move the batteries back without blowing over?
J.

[NativePaul]

Howard is the rudder long enough ? 1-1/2" below the prop tip about ?? tilting the rudder back will help the stuffing in the turns,, but sounds like you might be giving the boat right causing the boat to lift the rear putting the bow in & causing it to hook ???

Tilting the rudder was going to be my answer too, but isn't it tilting the bottom of the rudder forwards if you need help keeping the nose up in turns?

Yes. But the prop sits pretty high so almost not even in the water.

That won't be helping, increased prop walk is the main detriment of a high strut.

[Jesse J]

My thoughts without knowing which hull or any of the other details (critical to trouble shooting)
Possible things to adjust (one at a time):
1) cog too far forward
2) too much lift in prop
3) rudder too short
4) skeg may be causing unwanted lift
5) prop too high
6) servo not strong enough or rod flexing - does the servo pull when turning right or push? 300+ oz-in servo?

Does it spin under full throttle or when coming off?
Does it spin at entry, middle or exit of turn?
What does it do if turn is under full throttle and smooth?
Does it hook if you slightly tighten turn?
Where is your cog?
What hull? Maybe post a pic of underbelly?

Other than watching a video, that’s about all I got. Oh, and I most definitely wouldn’t reverse the rotation!

[srislash]

I’m just gonna sign into this thread as my HPR 115 does this. Chillin down on prop and voltage has totally helped.

[photohoward1]

My thoughts without knowing which hull or any of the other details (critical to trouble shooting)
Possible things to adjust (one at a time):
1) cog too far forward (Pretty well Balanced)
2) too much lift in prop (Possibly)
3) rudder too short (Possibly maybe a thicker rudder)
4) skeg may be causing unwanted lift (Doubt it but will consider)
5) prop too high (Come Spring I will Lower it)
6) servo not strong enough or rod flexing - does the servo pull when turning right or push? 300+ oz-in servo? (350+ on the servo but probably need stronger wire. Pushes not Pulls))

Does it spin under full throttle or when coming off? (Yes)
Does it spin at entry, middle or exit of turn? (Yes)
What does it do if turn is under full throttle and smooth? (Runs great.)
Does it hook if you slightly tighten turn? (No)
Where is your cog? (?)
What hull? Maybe post a pic of underbelly? (Elson Cat 50")

Other than watching a video, that’s about all I got. Oh, and I most definitely wouldn’t reverse the rotation!

Why not try a reverse rotation?

[jingalls007]

What hull is this?

[photohoward1]

Elson Cat out of the UK.

https://www.facebook.com/groups/1378695159037191/

https://www.facebook.com/daz.elson

[Jesse J]

Why not try a reverse rotation?

Why not?