Big Cat Hull

[Rolex]

That's what I need to change. I don't want to shut a motor off to steer. I plan to add a functioning rudder, or pair of rudders to a steering servo.
Another option is steerable outdrives. My Traxxas Villain IV had them, and they worked very well.
That boat also has an ESC that throttled both motors, with two batteries. I don't know if that type of ESC would be available for brushless, though.

 

[sweetdiesel]

A brushless ESC gets feedback from the motor wires as to rotor position and speed via electrical pulses. The ESC uses this information to control current flow to the motor. When you try running two motors with one ESC, the ESC cannot read the two sets of electrical pulses seperately and control the current flow to each motor independently. You "might" be able to get them to start and run in sync, but as soon as one of them loses speed or goes out of sync, the electrical induction that is fed back to the ESC would tell it to increase/decrease the same amount of current to both motors, resulting in even more out of sync condition.

 

[Rolex]

Good technical info, sweetdiesel. Thanks. So, would you suggest that I go with one motor?
Whatever I have to do for a conversion, is not a problem. I can go with one kick ass motor and one prop, or gear it to two props, and it's sounding like a single motor is the way to go. At that point, I'll eliminate any problem with the ESC, I guess.

 

[sweetdiesel]

There are many single brushless motors available that have more than enough power to replace two brushed motors. I would go the single motor route, to simplify set-up, save weight and also make more room for other components such as batteries. Some things to consider when selecting a brushless motor are:

How many rpms do you require the prop to spin to get your desired speed?
How many cells do you plan on running? (My suggestion is to go with lipo or limn cells for the least amount of weight.)
What is your budget for both motor and ESC?

 

[godale03]

How do you plan on controlling each motor independently if steering is accomplished by slowing one motor independently of the other? A seperate ESC would be required for each brushless motor. I could see how you would be able to shut one motor off through a mixing function in your transmitter but then how would you control acceleration?


Can you add a rudder to the boat?



I want to see how you shoehorned that Novak Velocity into your 18T!

Crap! I meant I was running a BL in the 18T, but also meant to put that I was running the Tekin BL setup in the 18T... Sorry about that... but now that you think about it... that would be some pretty sick power in that little thing! LOL

Tom

 

[beason]

nice boat rolex, i been wanting one of these for awhile, but dont really have anywere to run it.

as far as retrieval, i know you guys have fishing poles, put a small wire "hook" on the nose of the boat, and a lead sinker on the pole. cast it over the boat and the curve of the nose will slip the line right into the "hook" then reel her in. or you could use it as an exuse to go swimming... lol

 

[Rolex]

I'm going to thin out this thread and move it to the Marine forum shortly to get maximum info. I noticed a 33,000 RPM brushless, but didn't catch the price. Like everybody else, my toy money isn't what it used to be, so I'll be collecting the components little by little. By the time it's ready, I'll be converting it into an ice boat.

 

[vbgagnon]

DAMN Rolex thats huge! Should be fun to play with too!

 

[jmarzilli]

I recently purchased an Aquacraft Supervee 27 brushless boat, I'm sure one of those systems would be plenty. It requires 14.4 volt to operate and it gets my boat up to 35-38 mph.

 

[Rolex]

That sounds about right. Give me whatever info you have on that motor and ESC.

 

[sweetdiesel]

The motor is similar in size to a Feigao 540L with a 5mm shaft. They sell for 59.99 at Tower without the water cooling. The 45 amp ESC is also available at Tower. If you were to mimic the system from the Supervee it will cost you about $200 after adding all the cooling jackets and brackets. From what I am reading, the motor is a low 1200-1500Kv motor. Low Kv motors are designed to be used with high cell counts. You could forgo the Aquacraft ESC and get one that can handle more amps and cells.

If you want to go high end you could run a Neu motor (~$300) with an MGM speedo(~$250). How many cells do you plan on running?

 

[Rolex]

I'm just not sure yet, since I'm not that familiar with brushless. As much as I'd like to go high end, that's a bit pricey right now. I still have to invest in a good rudder and another Tx. I sold my last one, XR3, and I've been looking at the SX3. $199 at Hobbytown USA.
No problem with custom cooling. I'll dig up a pic of the Villian IV that I built a cooling system for.

 

[jmarzilli]

Check these guys out for parts, they specialize in fast electric. http://www.offshoreelectrics.com/index.php

 

[Rolex]

Here's the water cooling system I built for the Villain IV. I split the heat sinks and installed dip tubes underneath the boat, then routed them out the rear. Also, note the double heat sinks. That ESC was made to control two motors, with 2 batteries.

And there's the outgoing water being sucked into the props, through the aluminum tubes.

 

[Rolex]

I moved this thread here to the marine and airplane forum to get info on brushless motors. Pitch your knowledge at me.

 

[hamz9561]

Couldn't you run a splitter cable to the receiver and run dual ESCs and motors?

 

[Rolex]

I really don't know enough about brushless motors and their ESCs yet. Any advice I've gotten so far seems to lean towards one kick ass motor turning both screws. Also, I checked at the Local Hobbytown USA today, but they don't have much in parts for boats, just the RTRs.
I'll be checking a few sites for dual outdrives. Since the Villain IV had that setup, I'm familiar with it, and they also eliminate the need for rudders.

 

[Hypedonrc]

Sweet boat! I need a boat bad!

 

[Rolex]

ALL the factory graphics have been stripped, and I've done my own design. Now it's starting to BEG for speed. I'll try to get up some pics either tonight or tomorrow.

 

[Hypedonrc]

What made you go with electric?