trying to get into rc boats

[IowaSledKid]

new to rc boats but no stranger to the rc world. have had trucks and on road stuff on and off for the last 10 years. want to put together a boat to mess around with while were at the lake. not going to do any racing just want something fun and fast and kinda want it on the bigger size just for the wow factor.

id like to build it myself and what I'm looking at is the ml gsx 310 and 380. just wanting to build one or the other.

I guess what I'm after is a basic setup for either of these so i can gauge where both would come in cost wise. id like to stick to 6s max in either hull but I have no clue where to start with anything else. motor size and battery size. Iv seen where some people are talking about using the ul 1 setup in the 310 but that hardly seems like it would be enough. it would be nice to see about 50 ish out of either hull.

sorry for all the dumb questions if it even makes sense. just trying to get started. budget wise id like to stay on the cheaper side if possible. I don't need a neu motor to drive it a handful of times a year.

Thanks for any help in advance.

here are some pics of a boat i started building from scratch in college and got far enough to burn an esc out of as soon as it touched the water. its about 32 inches long. open to suggestions on finishing this one too.

[runzwithsizorz]

https://forums.offshoreelectrics.com...build-and-test

[NativePaul]

Lets try to find out what went wrong with your college boat, as that wil be the cheapest and most satisfying thing to get going. We need more information to find out why your ESC blew though. Can you post photos of the bottom and the hardware on the back. What gear (battery, motor, ESC, prop) did you have in it? What does it Weigh RTR (or let us know that it weighs as it is in that pic and we can add ESC, battery and radio on to work it out)? What was your driving style?

[Shooter]

The UL-1 setup in the GSX 310 with 4S should put you right at the 50mph you are looking for. This is the typical LSH setup for heat racing and its tried and true with an M445, M545, and even ABC H5 (watch temps).

[TheShaughnessy]

The ul1 motor will work, however, its at the upper end of its power spectrum with the props shooter mentioned. I would go with a slightly larger motor since you don't intend to race, it will be more worry free when you want to do more than run a mile at a time. I suggest something along these lines for your college cat https://www.offshoreelectrics.com/pr...rod=tp-3640-v2.

[IowaSledKid]

Thanks for the replays so far. On the 310 with the ul1 setup what's common for batteries.

Also on my boat when I popped the esc it has a feigao 10xl I think on 6s1p pro match 5000mah. Esc was a castle mamba monster (same as what comes in the emaxx brushless). Prop and weight I'd have to look at n I'm not by it at the moment. It made one good short pass before it went poof. Thinking it was over proped and too high on the kv. The motor in it currently is a lepord of some sort. Gotta check that too. I think part of my problem too was an air radio I was using cause I was in a hurry to try it. The hull was based off a PDF I found of plans for a mystic cat. It's a tick over 32 in from tip to transom.

[TheShaughnessy]

any 2s 5000mah 40+ c battery should do you. The 10xl is a 2 pole motor, which are a bit more temperamental when it comes to prop size. Several boaters use air radios without issue, in fact one of the fastest racers in the nation uses an air radio. You likely had too large of a prop, or you didn't add water cooling to the esc. I would try to keep the rpms at around 25,000 you could certainly turn more, many people do, but a little less rpm will be more forgiving and will allow for a wider range of prop selection. Rpm isn't what makes a boat fast, its the amount of power (A * V) you can create.

[IowaSledKid]

here are some pics. also tried to add a pic of the motor but didn't want to upload. motor in it currently is a lepord 3674 1400kv.

prop is a x445 octura.

[NativePaul]

I see a few things wrong:
The cat has a very shallow tunnel which may be causing drag, I would suggest adding ride pads if you want to continue with it.
The 10XL is 1668KV which is possible for 6s, but requites a well set up hull and a smaller prop would have been more appropriate.
The prop looks stock, is it straight out of the bag and unsharpened? If so that will add to the amp draw a chunk as well as cause handling issues.
Air cooling is not as effective as water cooling, some may get away with it in glass hules with large volumes but even then I wouldn't recommend it. In a partitioned wooden boat with a much smaller volume of air to circulate the vast majority of setups need water cooling.
On the plus side that Leopard 3674 1400KV is a great motor for about 50mph on 6s, and when sharpened the X445 may be a good prop for it, but start with a small prop and work your way up in size checking for temps along the way, that would have probably saved you in college.
Feiago are pretty low end and the market has moved on a lot from when they were the best bang for the buck, but while I wouldn't suggest buying one these days they still work OK, and a 10XL would still push a 30ish inch boat to 50 on 4s spinning a prop around an X445, but as ever, start small and work your way up checking for temps along the way.
I run an air radio myself, and many of my buddies do, there is nothing wrong with using them for boats.

[Fluid]

That cat is essentially an OPC hull with inboard power, it will need to run at a relatively high angle of attack to keep the amp draw down. The CG will need to start around 25% ahead of the sponson transoms. The strut should be set higher with around three degrees of up angle at the prop end.

The Faigao motor is "okay" and can be made to work if it has not been overheated (was it purchased used?). The prop may be a bit too much for a Fiegao although it would work with a four or six-pole motor. Try an x442 or equivalent CNC. The Leopard is a better choice and an m445 prop should work. Just run for one minute, check temps, run another minute, etc. Best if nothing gets over 130*F at first.

ESCs blow for a number of reasons, most due to excessive heat.

- prop too large
- battery too low in capacity/C rating
- battery/ESC wires too long
- run the boat for too long
- boat is plowing/running wet with excess drag
- inadequate ESC cooling
- motor magnets damaged, excess actual Kv
- excess ESC timing advance
- boat run over and over again with inadequate cool-down

I see a cooling error, the water exit out of the motor jacket must be on top and at the front of the motor.



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[Shooter]

I would hardly say you are 'new' to rc boating! That hull is quite an accomplishment. Looks great. That being said, I do agree with the tunnel depth statement. Also, the dihedral seems to be a bit excessive. I would bet that it will ride like it's on rails, and possibly hook in the turns.