Can I diminish prop walk more?

[Chenige]

First, I ran one of the Electrifieds this weekend with a Tacon 3650 with 2950 kv on a 5000 mAh 3s. X432 prop.

It ran almost too fast and with hardly any temp increase on the battery and ESC and just some on the motor even though it was often just plowing thru the water as I tuned it in.

My issue is prop walk. The boat under power had huge turning to the right.

The first run had the stinger centerline about 1/4" to the right and about 2 degree bending to the left . I had to keep the rudder to full left turn to get it to go straight under power. And when I let up it spun out due to the rudder angle.

I tried a 2nd run with the stinger angled some more but it still was not acceptable.

My last try is shown below. With the rudder trimmed as shown the boat would go straight w/o turning the rudder. Is this normal? What else can I do? I can see the back of the boat being pushed sideways as it takes off.

Do I need to add some kind of skeg? Move the rudder to centerline? Deeper rudder?

[driftah]

i have never sen a brass tube used for a stinger...or a stuffing tube bent like that before,just saying you may want to mount a small strut or stinger and straighten that brass tube out then look into other problems.the boat being pushed isnt a good thing you may be wasting forward thrust there bud and some powerful boats do have torque roll due to massive power being dropped instantly with a decent prop size but doesnt look like you have a crazy setup to cause that.plus that stuffing tube should be at the vertex of the transom imo.

[JackBlack26]

If I'm not mistaking, the new Pro Boat Impulse 26 uses a brass piece as a strut. Weird But it works, obviously.

[driftah]

ya it works but what about a bushing and or adjustability up and down?

[egneg]

I would change or cup the prop to narrow the thrust cone.

[jstolz]

I run my Electrified on 2S with a 27t brushed motor. I have to angle my strut, but not as drastic as your's is. It appears from the pictures of your boat that the rudder depth needs to be increased to help reduce prop walk. What prop are you running? A smaller prop will also help to reduce prop walk. Running 2s would also help to reduce prop walk.

[martin]

A stuffing tube like that is pretty common practice on Mono 1 & mono 2 Naviga race boats here in Europe all be it a much larger stiffer tube. Their put in at a given angle that works so no need for adjustments. Martin.

[Chenige]

x432

How deep below the keel should the rudder go? Does it matter that it is not centered?

[Chenige]

Rudder is about 1.25" below keel. How far should it go?

And should I center it?

I do use a brass tube for a water pickup in front of the starboard mounted rudder.

[dana]

i dont understand why the stinger is angled to the left here… what am i missing? what kinda boat is this? i would start by moving the rudder closer to the center of the boat….

[Chenige]

20" homemade wood. Used to be quite popular ~15 years ago or so.

Issue is that prop walk causes the back of the boat to go to the left which causes the boat to turn right. You angle the stinger to counteract prop walk. This boat really goes to the right probably due to a much more powerful motor setup than what they used 15 years ago.

[7500RPM]

Rudder is about 1.25" below keel. How far should it go?

And should I center it?

I do use a brass tube for a water pickup in front of the starboard mounted rudder.

I ran my boats with home made brass tubing struts with Octura teflon bearings for years, worked great! but you need to change the water pick up to one mounted flush with the bottom, the issue is the tube sticking below the transom like yours, it will cause the hull to do strange things! Also you will need to rebalance the hull from the old days as you are running Lipo's, the motor in the stock position will make the hull run wet, and push on the nose

[Chenige]

The water pickup upper surface is about 1/8" below the bottom of the boat. I will raise it up 1/8". Is this what you meant?
P1040418.jpg


With the battery straddled just behind the motor as shown below the balance point is 5.5" from the transom, about 28%. This really ran well.

I think I am going to put in a different mount and put the battery on the left side of the boat to counteract the torque and allow repositioning the battery for balance adjustment. However this will probably not help much with the prop walk?
P1040380.jpg

[siberianhusky]

Is the prop sharp enough to cut your finger easily? Dull props can cause severe prop walk.

[Boaterguy]

trim tabs may help a little, but not much
It ma yjust be that the hull is not built for power since it is 15 years old