MotoManGXP

So i'm trying to find some plans for a 30-36 inch rc hydroplane. im using junk rc parts to build it, but i have a few questions.

How much balsa wood do i need?


how much will the balsa cost?

how to i make the boat waterproof?

What should i paint it with?

thank you for any and all awnsers!

Got RPM

Have you ever built a model boat before? What power (volts, motor, ESC) will you use? What kind of running will you do? Do you want a scale hydro or an outrigger hydro? What plans will you use?

Balsa is a poor wood to use for boats today if you want them to last or to go fast, most builders use different sizes of plywood for most of the boat. There are several ways to waterproof the wood, many use epoxy spread over the wood, then sand and paint. Others use primer/filler then paint.


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MotoManGXP

i have never built a boat. i also learned a deep v is easier to construct. btw, thanks for the info, i have a LOT of plywood unused.

i'm just looking for something to get me started, as i have never had an r/c boat. i do have a lot of woodworking skills, so i thought this would be a good project for my school.

i'm using a tamiya esc, ( from grasshopper ) a spektrum radio, a nimh battery, futaba servos, and i have yet to purchase a motor. im thinking a brushed 550?

does this help?

xsthomas

If you're thinking of building 30" - 36", a brushed 550 will not be a wise choice. A 550 motor in a hydro you will need something like a small ABS plastic hull.There are plenty to choose from. Go smaller if you choose a 550 motor. I have built all kinds. I choose the motor after the build. Sometimes I have a motor size in mind during the build, But kv and voltage to consider. You have to consider weight of the boat, size and kv of the motor, cell count and prop size. It will be a trial and error sometimes to get up up on plane to run correctly with decent speed and run time without burning something up. All of which can and will happen. It's a fine line to choose the right components that go together. Vehicle esc dont usually work well in a boat, They're air cooled. It is fun though in the trial and error stage in fine tuning a boat.

MotoManGXP

ok, so ill just start with the hull, and save up for better electronics then. is there like a jet pump system i could install ( like a jet ski? ) i actualy have enough wood for a 56 inch hydroplane now. should i do it? will it be more stable?

also, where can i find blueprints for this? how do i read them/ assemble them correctly?

i also just want to say thanks for all of the help, and i am so exited to do this!

my general idea for the boat is to make the skeleton balsa, then plank it with plywood, like GotRPM said.
then i will paint it like a 1970's racecar, light blue and orange, with a white circle with "#1" in the middle.

I will think of its name later, but just wanted to update my progress. i have the wood all purchased, and am looking into electronics as we speak.

MotoManGXP

update: found a jet pump system!

Got RPM

Jet drives just don’t work with hydroplanes. The whole idea of a hydro is to minimize contact with the water, with just the backs of the sponsons and the prop touching the water. A jet drive requires a large portion of the hull to be in contact with the water. Jets work best in relatively flat-bottomed monos, not hydros or cats.

Do not make the mistake so many new boaters do by trying to build an exciting-sounding boat that even experts would shy away from. Doing that guarantees you will never finish the project, just spend $$$ on parts then lose interest when it gets too tough. Unless you have a kit or a proven set of plans to build from, don’t build a hydroplane. To work a hydro needs the correctly designed sections - do you know the best aoa and dihedral for the sponsons? Where the CG should be located? The prop angle and depth? Length of afterplane? Turn fin location? If not, I strongly recommend you get a kit like the one below. It may cost more, but assembled correctly it will run great, and save you lots of time and frustration.

*GP Sport Hydro Kits - *Sport Hydro Kits - Wood RC Race Boat Kits


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Hydro Junkie

Okay, let me give you an idea of what it's going to take to build a hydroplane. I've pasted the address to a thread I did in building a modified kit build below that would apply to your plan of building a boat. Along with the link, here are the answers to a few of your questions:
1) As stated above, don't use balsa or lite ply. Both are not good in the water since they will absorb water through any gap or scratch in the finish, ruining your boat. Home center plywoods are also not good. To build a boat that will hold up, go with aircraft grade plywoods from the hobby shop
2) Waterproofing is easiest by applying a thin coat of epoxy to all of the wood AFTER the parts are assembled. DO NOT THIN THE EPOXY WITH SOLVENTS!!!!!!!!!!!!!!!!!!
3) Since you plan on using an electric drive, just about any paint will work. Krylon would be a good choice since it's not expensive and is water proof
My link for a build thread: http://www.rcuniverse.com/forum/spee...-payn-pak.html

MotoManGXP

Thanks to you both. ill just stick with an outboard motor, and ill take a look!

MotoManGXP

So, ive looked at the build. so its difficult. so, should i build a deep vee instead? arent they easier to construct? im also returning the wood for hobby grade aircraft plywood. so, is there a reputable online source? normaly i would do local, but the nearest shop is 2 hours away.

MotoManGXP

so, im ordering the wood, and i decided to stick with a deep V. build thread coming soon.

Hydro Junkie

Trust me, building a boat isn't hard. What is hard, for most new builders, is to take the time to build a boat properly. I've seen boats that were basically thrown together that literally exploded on the water due to shoddy workmanship.
Let me give you a couple of suggestions:
Dumas Products Estore
Easy Vee Easy Vee Model Boat Kit - $59.00

MotoManGXP

thank you! i am looking at the Easy Vee. is there a canopy?

Hydro Junkie

You would have to contact Joe on that one

ob nut

My Feedback: (1)

if you want an outboard, I've got several WOF plans from Jerry Dunlap. These are somewhat easy to build as they are wood over foam.

Hydro Junkie

Mark, you forgot the best part:
A WOF boat is virtually UNSINKABLE!!!!!!!!!!!!!!!!!!!!!!!!!!

Ron Olson

My Feedback: (1)

An Easy-Vee is a little big for most outboards as it's made for stock inboard gas engines. Joe will be releasing a new version of the Easy-Vee but won't be ready to sell until at least April with a lower profile. There is no canopy available for the kit, you'd have to make one.
Now, if you want to use an outboard then Zippkits does have an OB outrigger kit for .21 nitro engines.

ob nut

My Feedback: (1)

I would like to see a WOF boat sink! Drop "virtually" and it's 100% correct!

30", 34" and 47" plans available to anyone, just ask. Jerry normally sends anyone looking to me for these plans, so don't worry about any cost. They are free. You'll just need to find a print shop that can print them for you.

Hydro Junkie

The word "virtually" is there because many things that were claimed to be "unsinkable", such as the Titanic, Bismarck, Yamato and many others are now sitting on the bottom of the ocean

ob nut

My Feedback: (1)

LOL. Yea, true, but their hulls were filled with H2O, not foam! That is why they are now in Davey Jones' locker! At one World Tunnel Champs race, saw where JD had a sponson come off, separated at the center section. Next heat, boat was back out there after the glue dried.

Hydro Junkie

But you have to remember something. With JD, he'd probably throw a boat on the water that was missing a sponson rather than take the chance of missing a heat

ob nut

My Feedback: (1)

He would most likely win that heat also!

mohhasco

Hello Guys ... I need some technical help ....

I bought brushed dc motor 775 from (aliexpress(dot)com) and an ESC (RC Boat 7.2-14.8V 480A ESC 380/540/775 Brushed Motor Speed Controller Dual Mode Regulator).

The seller told me they work together fine ... However, I am using a 12V/12A Lead Acid battery to operate the system and I would like to use the Arduino to control everything on the boat. I am using Xbee for communication. My questions are:

1. Is the battery fine to be used along with ESC and motor? Is the ESC is suitable for the motor ?

2. I am not using an RC receiver. Instead I am using Arduino to send control signals. The ESC has three wires for control: black, red, and white. I connect the black to GND, White to PWM signal from the Arduino. What about the red ? Do I connect it to the Vcc = 5V ?

You help is highly appreciated... Thanks

mfr02

This thread started as a discussion about building a fast boat. What kind of boat is this? Perhaps a nice new thread of your own would avoid confusing two different projects.
One of the very last things you want in any fast boat is unwanted weight. SLA were the only choice several years ago and designs had to use them and cope, but the world has moved on.
SLA disadvantages are -
1 very heavy for the power that they can store
2 while they can deliver a very high current, they can not sustain it for more that a few seconds before they either discharge or damage themselves.
3 because of size and weight, often difficult to place where they need to be.

The "480A ESC" probably isn't. Probably one of the "320A" ESCs but fitted with a water cooling jacket. When it comes to brushed ESCs, the numbers on Chinese ESCs are just decorative marks without any real meaning,. Either they don't mean anything or they are the result of hopeless optimism or just downright lies if they did mean anything when written. It "might" be OK with the motor depending on how heavily the motor is loaded by the prop.
Not many on here will be familiar with Xbee. The ESC has a BEC built in which outputs a regulated +5v on the red wire having derived it from the main battery .
​​​​​​​The "775" just refers to the length of the motor can, no real clues as to its internal arrangements which will determine its performance.

Hydro Junkie

Mfr02, this is actually the third thread he's done this in. In the second, I outlined how spamming is unacceptable, as well as hijacking the threads.