Nodd's Airboat

[Nodd]

Paint (continued)
Day three of painting I believe. The light green & white are done...



Moving onto the dark green...



And here she is...



The rudders got some fun stripes...



Now that's done I can get back to putting her together...

[Don Sims]

Looking good Nodd!

[Wildflyer]

Nice looking airboat Nodd.

You might find you need some strips or small ridges on the bottom.
I built a similar looking airboat in the late 60's. I had a Range Master 8 channel reed/relay radio system, I couldn't afford a plane big enough to lift the radio system.
Receiver, 4 servos (I had the small ones), 1 battery pack to run the RX, and 1 battery pack to run the servos, weighed about 24 oz. So I figured I could at least float the darn RC system.

My boat didn't look any where close to as nice as yours, I just cut an angle on the front of a 16" x 24" piece of hard foam, then a cut out for the RC box built out of 5/16" plywood, put a K&B 19 on top, my rudders were almost like yours. We went to a small lake. It went fairly fast considering how much weight was moving but would slide sideways instead of turning. I then glued 3 pieces of 1/4 x 1/4 spruce to the bottom then it turned just fine.

Now one of the clubs I am a member of, cleared out a low area at the field, and use it for seaplanes, and airboat races, so now I have to build another boat.

I enjoy your builds, thank you for sharing your designs.
What software do you use?

[Nodd]

Yeah I don't know how she'll handle with the flat bottom Dave. I know many boats need turn-fins & whatnot but then again the forums & YouTube are filled with flat-bottomed airboats just like this one, zipping happily around no problem. If she does end up sliding sideways instead of turning, I could add rails or ridges although I'll probably look at a few other options before taking that route. I know balance plays a role as does rudder area/design. To be honest I'd kinda like her to "skid" around the corners a little & I'd rather she fish-tailed Vs flipping over if I crank the wheel hard over. *shrug* I guess we'll see what she does.

Mounting the Rudders (continued)
The top of the rudders are firmly hinged just behind the motor mount. I also need to secure the rudder bottoms. For that I used a 34¢ piece of aluminum sheeting from Home Depot. I used tin-snips to cut it to shape...



This bolts-up under the main pylon. The piano-wire running down though the rudders indexes two holes in the plate...



To keep the rudders from popping out of the plate I secured the end of the wire with a couple of set-screws. Here's a view underneath before it was mounted...



To link the rudders together so they move as one I bent a short length of piano-wire to bridge the gap...



The mounting hardware is a regular set of Great Planes' control horns. I just snipped 'em off short & drilled a new hole...



And then I took everything apart
Well I thought I was done painting but noooo. For some inexplicable reason I decided she just had to have an orange nose...



Hey watch the paint job!
As with most of my airplanes I found myself taking care, while working on her, to not scratch the paint and then I thought, what the heck am I doing? This is an airboat that'll likely get beat-up running on snow, ice, grass, mud, you name it... watch the paint? So I'm adding "superior durability" polyurethane clear-coat over the entire hull, bottom especially...



That should do it for the paint... I promise. Tomorrow I hope to get the electronics installed.

[mclarkson]

That's looking great, Nodd. You're gonna force me to exercise my extremely rusty CAD skillz.

[Nodd]

Go for it Mark *smile*

Installing the guts
I dropped in my Chinese-takeout-food-container-radio-box-o-doom. Added lots of silicone to seal her in tight...



Adding bullet connectors to the motor leads...



Time to install the electronics...



I figured I'd keep things simple & just hot-glue in the rudder servo. Well that lasted all of two minutes, she popped right off. So instead I used some foam, scrap aluminum & whatnot to fabricate a proper servo mount...



Roughed up the inside of the food-container & epoxied in the servo mount. In no time I had the rest of the gear secured too. I used double-sided tape for most of the other stuff...



I spent some time programming the radio, getting the gyro setup & testing the throttle...



It floats!
The all important bathtub test. She sits pretty level with the nose raised slightly. The balance point is right around 2/3 from the bow, so she's looking good there...



DONE!
She cruises around my living-room carpet very nicely *grin* I'll take her out this weekend for some test runs. Stay tuned for the video...

[xmech2k]

Nicely done! Looks great!

[gramps2161]

Nodd your air boat looks great.
Did you use speaker wire for the extension form the ESC to the motor kinda looks like it in your pic.

[soarrich]

Great looking boat.

Chinese food tray, great idea, but when you're done an hour later you're going to want to go back to the pond and do it again.

[hkeelljr]

Way Cool!!

[stuart]

funny thing nod,i'm looking more forward to your settng this boat in water than the stinger i still have to maiden...,i guess it's do to cold weather here in nj.

if she's a go today for the maiden ,please post a video for all us flyguys/gals to see and who knows....maybe we'll have to add boats here at wattflyer.[jk moderators......please don't ban me]

[Nodd]

Thanks guys.

Originally Posted by gramps2161

Nodd your air boat looks great.
Did you use speaker wire for the extension form the ESC to the motor kinda looks like it in your pic.

Yeap that's speaker wire in there. It was that or some lamp-cord I had laying around. The rest of my scrap wire is too smaller gauge.

Well you've all been waiting for this so here goes...

Click to watch video...
Nodd's Airboat YouTube Video

[mclarkson]

LOL. Nice. Congrats on your project, Sir.

[JetPlaneFlyer]

Nice video. Sorry to see it picking up siome damage but at least nothing that cant easily be fixed.

I wonder about the wide turn circle on water.. Could this be because the boat has no keel and a flat bottom so it 'skids' sideways as it turns? Increasing rudder travel may only make the skidding worse. If so the solution might be to put a couple of small 'keels' along the bottom, just something like 1/4" square strips of balsa or plastic.

just a thought...

Steve

[soarrich]

Cool. Try the fin! Watching your first test I would say the wind was at your back because the nose of the boat keep turning to you, the fin will help that. Boy that gyro was impressive, I bought some of these at HK:
http://www.hobbyking.com/hobbyking/s...dProduct=28456
Are they like what you are using?

[rcers]

Very impressive all the way around. Great job!

[CHELLIE]

Great build and Run Nodd Take care and have fun, Chellie

[Nodd]

Thanks folks. Yeap I'm pretty happy with the boat. I might have too much motor on there but I'm okay with that. I just need to behave myself & not listen to club mates egging me on to "GO FASTER!" The extra power will be nice for going up hill *grin*

Originally Posted by JetPlaneFlyer

Nice video. Sorry to see it picking up siome damage but at least nothing that cant easily be fixed.

I wonder about the wide turn circle on water.. Could this be because the boat has no keel and a flat bottom so it 'skids' sideways as it turns? Increasing rudder travel may only make the skidding worse. If so the solution might be to put a couple of small 'keels' along the bottom, just something like 1/4" square strips of balsa or plastic.

just a thought...

Steve

Yeah the hull is taking quite a beating. I'm thinking I should have used heivier fiber-glass & more resin. Something to consider for the next hull.

You're not the first to suggest turn-fins or keels on the bottom. I have a couple of problem with that though. The nice thing about airboats is their clean-flat bottoms can skim over any surface, water, snow, ice, grass, weeds, etc. Placing stuff on the bottom would likely snag on stuff. The other nice thing about airboats is that they do slide when turning. Kinda like a car fish-tailing or doing donuts in the parking lot. That's half the fun in my opinion. Anyway I believe the wide turning issue has been solved by simply increasing the rudder travel. As you can see from the snow footage she spins around in nice tight circles now. Lots of fun.

Originally Posted by soarrich

Cool. Try the fin! Watching your first test I would say the wind was at your back because the nose of the boat keep turning to you, the fin will help that. Boy that gyro was impressive, I bought some of these at HK:
http://www.hobbyking.com/hobbyking/s...dProduct=28456
Are they like what you are using?

Yeah I did notice some weather-vaning when the wind was blowing hard. Once I turned the gyro on however that seemed to fix that. Well at least when I was moving that is.

That HobbyKing OrangeRX gyro should work fine in a boat. Obviously that's three axis (yaw, pitch, roll), you'll only need yaw in a boat but I don't see any reason why that shouldn't work. Assuming you want to use the right stick to steer, you should use the aileron output on the receiver, plug that into the rudder (yaw) port on the gyro then rudder out to your rudder servo. Here's how I have mine setup...

Gyro Setup
I'm using a Detrum GY48V gyro. It's a pretty standard unit, usually used in helicopters but it'll work in anything RC...



Setup is pretty simple, you just hook it up between your receiver & rudder servo...



A nice feature of the GY48V is the remote gain control. It comes with an extra red plug that you insert into an unused channel on your receiver. Map that channel to a switch or the rotary-knob on your transmitter & you can dial in as much or as little stabilization as you like, all while you're driving/flying.

Orientation of the gyro when you install it in the hull is important. This unit only senses a single axis so in the case of a boat you want to orient it so it can sense if the boat turns either left or right (yaw). It doesn't care about rolling from side to side (roll) or rocking back-n-forth (pitch).

This gyro has two modes...

Regular
Counters any yaw movement by turning the rudder in the opposite direction

Head-lock
Turns the rudder either way until its facing the initial direction

For a boat you probably want to use regular mode, that's what I've been using. There's lots of other gyros on the market, for the most-part they all work the same (hookup between with RX & the servo). Some have remote gain control, some don't. Either should work fine.

[Nodd]

I've also been asked about how a reversing ESC differs to a standard one...

Reversing ESC Setup
Most boat or car ESC come with the reverse feature. The boat ESC are water cooled so that wasn't an option for my airboat that runs on land too. So I went with a fan-cooled car ESC. Setup is pretty simple, you hook everything up as usual with the ESC plugged into the throttle channel. The throttle channel on a reversing ESC is a little different...



So when used on an airplane radio, you have to center the throttle stick to stop. Chances are your throttle stick has no self centering so it's a bit tricky to operate. Set the "null zone" on the ESC to its max. That'll give you a fair sized area around center that'll shut the motor down. It's not ideal but it works.