Firest FE boat I ever built steering hard right at full throttle

[Elysian722]

Fairly new to the forums...I've been having fun with my "new to me" SV from Nate but enjoy building as much as running so I am now back to trying to get my very first project boat back up and running in all its amateur built glory, I built this boat last year from an inexpensive ABS hull and old heli parts I had laying around:

Hull is about 22" long. Boat is running a scorpion 3000kv HK-2221-10 outrunner have run props on it from 38-42mm just for testing, Futaba High torque BB servo and running the boat on a 3S 4400mah battery pack.

kept frying my cheap 40A ESC's and motors that I had laying around so I purchased a generic 120A with BEC on the forums here and dropped in a Scorpion Outrunner (sticking with an outrunner since thats what I started with)

That ESC and the scorpion outrunner are the only two changes to the hull and it has never done this before.

Now every time I start to get up on plane, the boat immediately corks right. like hard right spinning in circles before I can get anywhere and I lose steering. (it has never done this before) It appears the servo is turning right when the boat starts to get up to speed, but does not even wiggle when the boat is run at full throttle out of the water... put it back in .. spins in circles.. my thought is BEC issue with the increased amp draw? It has a seperate BEC soldered on the battery side.

I'm hoping that someone on here with more experience than I will have some advice. Please Help
Thoughts?

[screwball]

dont quote me on this but it could be that tthe new motor and esc are drawing too much amps from the battery all at once because of the load on the prop and this is causing the servo to lose power or maybe even gain too much power and making it to turn a certain direction
all i can think of to do is maybe run a larger pack or run the 3s`s in series to get a higher mah also try switching to the origional motor

im new to boats also but this is just stuff i know from my bl rc18t


-James

[Elysian722]

Thanks for the feedback,
I don't think its the battery packs though, These packs are 20C 4400mah.. that puts them capable of well over 80amps... I can run my SV with a 12L and x442 on the same 3S pack without any issues whatsoever..

[Jesse J]

any video of this corky behavior?

[Elysian722]

no vids at this point.. last run out, the wire drive pulled out of the flex hex so waiting on the new one to come in... I'll try to get some video of it once my new prop shaft gets here.

[NorthernBoater]

What brand of batteries?

[Steven Vaccaro]

Did you try running a separate rx pack.

[sailr]

Are you using an AM radio? Could be the new esc is very "noisy", causing erractic control. Just a thought.

[Elysian722]

Northern,
The batteries are down at my shop and I don't remember the brand off hand.. they are a generic pack out of Hong Kong.. I picked them up on Ebay a while ago before I had learned much about lipos.. they are 20C with either 25 or 30C burst. I just ran them in my SV while I was waiting on my Rhino 2S packs that just came in.

I'll try to take a look next time I'm at the shop.

And Steven Thanks for the reply, All of my ESC's have a BEC so I've never run a seperate RX pack. I will try that next time out.. would be a quick way to tell if it is the BEC. If my memory serves me right they require 4.8-6V right? I think I have some 4.8Nicd packs laying around and I know I have a 4xAA RX pack here somewhere too.

Thanks for all the replies guys.. much appreciated.. I have a lot of blood sweat, tears, and learning into this boat .. would just like to get it reliably running.
-James

[Elysian722]

Salir,

It is a cheap AM radio in that boat.. I do have a better Hitec radio.. I'll start by running the RX pack and if that doesn't fix it, then I'll try upgrading to a better radio.

[Jesse J]

Remember to disable internal BEC otherwise bad news.

[Elysian722]

Thanks Jesse..

probably would have missed that step.. how does one do this?
And your signature is so true.. I learned that the hard way trying to build this boat on the cheap to begin with.. .it would be fun for five minutes then die.. I got fast and cheap... not such a good combination, but a great learning experience nonetheless. (and still is evidently)

[Jesse J]

several ways. the easiest is to pull out the red wire from the connector and fold it back securing it with electrical tape. you can cut it, but then don't have the option of using it again. Otherwise, you can add a 6" servo extension and remove a chunk of the red wire - this allows you to switch between internal and external bec w/o having to do anything.

[FRED]

Steering goes crazy

The best rx power is a camera battery at 6 volts and ultra light. Just velcro boat and battery and add wiring to battery to go to rx. Servo need not be replaced, just power for servo to work under w.o.t.. What ever you do , don't cut red wire, just tape it back incase you ever go back to bec. Extension wire; just unhook red wire on both ends and tape back and your done.

[Elysian722]

Ok, wow thanks all for the feedback. This really is a great group here on the forums.

Do I still need to disconnect this infamous redwire If I don't plug in the BEC at all?
It is a seperate BEC wired on the battery side of the ESC. So couldn't I just leave that disconnected and run on an old Traxxas 4xAA RX pack that I dug up while I was in the shop today? I believe the RX I'm using has a Battery input.

And Northern, the batteries just say RC Modelpart on them.. just generic Lipos. Nothing fancy, but they pack a punch for the price I paid.. we'll see how many cycles they are good for though... They go on Ebay for about $30-$35. I think I've got about a dozen cycles so far and they seem to be holding up well. They're just a little past warm after running my SV with a 13L Feigao and X442. (except the one pack I foolishly shorted while soldering on connectors that released all sorts of cool smoke and was quickly taken out of commission)