Torque steering under power

[RC boat addict]

I have a 34? carbon fibre rigger it has a tp4060 1650kv on 8 s running a ZTW 200 amp esc with big cap pack and 2x4s 5000 mah 100 c hrb lipo?s using a 3/16 flex cable and spektrum stx3 with MRX 200 waterproof receiver with glitch buster and a 1820 abc cleaver 2 blade prop. Best speed 107 mph
Now to the issue,
One day out of the blue it started swerving to the right under acceleration no matter how slow I pull the power on. I tried disconnecting the esc?s in built Bec and ran a nmh receiver power supply instead thinking the power demand of the motor might be starving the steering servo. That did not help.
I tried a smaller prop 1816 abc cleaver to no avail (I figured it wasn?t the issue given it ran perfectly previously with the 1820 prop).
There is no looseness in the steering and turn fin. And has been no change in any setting since it ran correctly.
The strut is tight and running the same angle. No amount of steering bias helps.
I am at a total loss to what?s going on and what to try.
Has anyone had something like this happen at first of all for no apparent reason that they found the answer too.?
Please help.

[koen]

it sounds like the steer servo is not holding the rudder i had the same problem with a cat ,the simple solution was change servo for a 20kg torque and no problem any more

[RC boat addict]

I?ll give it a try, I?ll try anything I?ll let you know how it goes

[Alfa Spirit]

How are the strut and the rudder at the neutral position? Is the rudder inline?

[RC boat addict]

How are the strut and the rudder at the neutral position? Is the rudder inline?

Rudder slightly turned to the left as is the turn fin via the rh sponson on 2 mm toe in strut zero AOT and zero turn. The Zohar sponson 10 mm further from tub than the RH one is and the motor and flex and strut is offset to the RH side about 3/4? this set up ran perfect for about 30 runs until it started torque steering.

[donhuff]

I would check the leading edges of the prop. See if there is any damage or slightly bent tips.

"torque steer", bow steering, nose diving, and spinning out in a turn, are all different names for PROP WALK. Riggers are especially prone to prop walk, because the prop is running so high out of the water once it gets high and dry at speed. The blade tips are striking the waters surface not necessarily at 90 degrees downward, but actually at some angle which tends to pull (walk) the rear of thee hull left, and thus the front looks to be going to the right. Diameter increases the effect, as does high pitch. Also P-factor, an aviation term, comes into play to a smaller degree. Angle of the strut will increase or decrease it's effect.

Sharpen your prop like a razor and see if it helps any.

[RC boat addict]

Thanks man but the prop is perfect no damage and sharp as a razor from Dasboata.
My rudder is a hardened knife blade and also razor sharp.
I have a new 25 kg servo coming in about a week so I?ll try that before changing anything having said that all your info is great for me to refer back to if the servo does not help.
I?m hoping the servo is the problem as none of my settings have moved and no damage has occurred it just was perfect going one way on a run and then crazy veering to the right on the way back.

[koen]

do have checkt your TX and RX for reach ,with your speeds you are fast out of reach from the TX

[RC boat addict]

I am using a spektrum radio with really long range but it torque steers even when it?s close to me

[GreatWave]

I'll give it a try.

[donhuff]

Dang it! I was hoping that the prop had a buggered up spot on it.
The main thing that I was trying to say is that most all trim adjustments are trying to correct for the problems that the propeller are causing to upset the hull.

Has it run correctly with that "knife blade" rudder before? We have tried them in the past and had nothing but problems out of them. A wedge rudder has always worked better.


I use a "rectum spektrum" radios too. And I always have problems when at straight away runs because of getting out of range. My fault though. 10 years old and cost $79 when new.

[RC boat addict]

I have always had a knife blade rudder on this boat in fact all my boats have them with no issues.

[RC boat addict]

Thank you so much I am hoping to find time this week to start trying things that I don?t think have changed but what else can I do. Front sponson AOT is first then possibly a straight turn fin just to make sure it?s not the curve somehow Obviously I have tried different positions of it already.

[Ivan Kozyakov]

I have a 34? carbon fibre rigger it has a tp4060 1650kv on 8 s running a ZTW 200 amp esc with big cap pack and 2x4s 5000 mah 100 c hrb lipo?s using a 3/16 flex cable and spektrum stx3 with MRX 200 waterproof receiver with glitch buster and a 1820 abc cleaver 2 blade prop. Best speed 107 mph

Very interesting. What rigger hull are you using?
I am updating a very similar setup to the hydro Dr Super-Evil but with a 1350kv tp4060 motor and 8s.
Do you experience problems with temperature at 1650kv? And was a 200A ESC enough for you?

[RC boat addict]

The rigger is from Europe it?s called an Endgame I was getting 6 passes all over 104 mph the 2nd pass at 107 about 300 - 400 yards long no temp issues maximum was 140f (the ABC prop is an 1820 cleaver and it?s probably a bit big as the speed was just over 100 with a ABC 1917 cleaver).
One day it just stopped on a short low speed run during testing to fix the torque steer then nothing out of the esc but the steering, so I put a 250 amp Hobbywing ezyrun max5 with a water cooling kit on it I bought off AliExpress So far no speed runs due to the torque steer though.
The ZTW 200 was 5 years old and I run in full salt water. So who knows what killed it.

[CornelP]

One other possibility is the distance between body and sponsons: check if they are still ok. I give it a bit of camber (sponson tips closer to the body by a few mm) and it helps a lot. Another issue to check is the turnfin: but the boat on a table and make sure that the curve of the turnfin is parallel with the table. If the angle is not 0, it will have a tendency to dig in or take off and mess up the position on the water.

[vvviivvv]

Maybe post a pic of the hull / setup or a link to the hull so we can see if anything jumps out ?

[RC boat addict]

Thank you but this boat comes with this camber and I have already taken the curved turn fin off and fitted a straight one also the sponson has about 60 thou toe in
the left is straight. I am just waiting on flat water to test

[RC boat addict]

I don?t remember how to post a photo. I will look into how

[RC boat addict]

I tried to run the boat in a narrow creek this morning with a smaller cnc prop 4716 seamed slow on the first pass it was not detongued so at least it go up on the plane fast still torque steered but it was different but the run was cut short before I could do much testing as it hit the bank in a turn.
Now I have a sponson repair to do. But can anyone tell me if it?s best to have the rudder behind the prop or in front of it ?
For sharper cornering

[RC boat addict]

All repaired and found the issue with the torque steer I think.
I had broke the sacrificial rudder bolt and when I fixed it I removed the rudder for some reason and then I refitted the rudder blunt side forward. What a dill. Testing tomorrow.