Motely Crew Going Left!

[yoffer]

Alright guys, i need some help on this. Im having problems with my motely crew turning left. Anything under half throttle it will slowly turn left and eventually make a big left hand circle. But anything over half throttle or when it gets on plane it will go straight no problem. Heres a video so you can better understand what im talking about. I dont know if any of you guys are having the same problem im having. And please note i still need to tweak the strut/battery location to help fix the hopping on full acceleration.

http://www.youtube.com/watch?v=GOmuppeqvH4&feature=youtu.be

[yoffer]

Just got off the phone with phil at hobbico. He assured me that this was normal and most likely a hull issue. He says that there may be differences in the sponsons on both sides that cause it to go left when most of the hull is in the water (not on plane). What do you guys think?

[Grimracer]

Just got off the phone with phil at hobbico. He assured me that this was normal and most likely a hull issue. He says that there may be differences in the sponsons on both sides that cause it to go left when most of the hull is in the water (not on plane). What do you guys think?

What Prop?

Grim

[yoffer]

What Prop?

Grim

Hey Grim, in the video im using a S&B x442, however i did notice it when i was using the stock prop, but with the x442 it seems more pronounced. I do, however, have a prather 220 coming in the mail.

[Barbossa]

I have experienced the same thing with an Octura X442 and a M445. Normally at about 25 - 30% throttle it veers to the left….when it is above 50% or up on the plan it is straight.

[Fluid]

I have seen this on my 10S Stryker cat, goes straight under power but back off too quickly and it turns hard left. Other than a warped hull I have not been able to determine why this happens.


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[sanyijr]

You know, props at low speed tend to pull to one side. If you look at any inboard/outboard boat (full size) they all have these little fins to counter the slow speed prop rotation effect. Not sure about the technical term for that, but with more prop in the water and more surface area in contact with the water, you would get a more pronounced effect. So the 30% thottle range makes sense.... But so would a warping in the body where the hull is in contact with water only at high speed. But it don't have to me a curved warp. It could be a bulge just on one side from a battery, or compression into the hull from bad storage.... Just a thought...

And as i think you have approached it, try a smaller prop and see what the effect... As a bigger one would surely make it worse.

Sean

[yoffer]

You know, props at low speed tend to pull to one side. If you look at any inboard/outboard boat (full size) they all have these little fins to counter the slow speed prop rotation effect. Not sure about the technical term for that, but with more prop in the water and more surface area in contact with the water, you would get a more pronounced effect. So the 30% thottle range makes sense.... But so would a warping in the body where the hull is in contact with water only at high speed. But it don't have to me a curved warp. It could be a bulge just on one side from a battery, or compression into the hull from bad storage.... Just a thought...

And as i think you have approached it, try a smaller prop and see what the effect... As a bigger one would surely make it worse.

Sean

Are you referring to all boats or just cat's? Because i run this prop on my sv27r and it doesnt go left or act different at all.

[jmatak9]

Try a smaller prop or offset the rudder some. When you set the hull on a mirror or piece of glass, is it true? does it wobble on the glass at all?

[yoffer]

Try a smaller prop or offset the rudder some. When you set the hull on a mirror or piece of glass, is it true? does it wobble on the glass at all?

When i set it on a flat surface it does wobble just a VERY small amount.

[siberianhusky]

Mine runs much better since I filled in the trenches down the sponson centers and sanded everything flat so it doesn't rock on a glass table.
I also stiffened up the boat substantially with wooden rails running the length of the tub as well as crosswise.