CTSmithey

My Feedback: (2)

My dad and I have built a Airboat out of a boogie board. We have read a lot about it and wanted to try this out since we had a old Ryobi 31cc weedwacker laying around. We were "hoping" to get off cheap well HAHA! we learned nothing is cheap.This went from a maybe 100$ job into now at 200+ and needing new servos on only her 2nd run. 1st and 2nd run on water both times she fliped in turns, 2nd time was a flip at idle we are a bit frustrated here.

A little back ground on the build. We used all aluminum for the frame work, the rudders we made out of a thin NOSMOKINsign hehe, we just added the small side fins you see after I flipped her at idle the other day. We have not "converted" the engine with a prop hub we had a piece of aluminum stock and made it our self. This old motor was used for 6 or 7 years of wacking his property so it has mass hours on it but it ran we just rebuilt the carb and tossed new lines and primer bulb on it to get it working. We are trying to learn by doing it this way about how to place things, what to look for. I was told we got to get our gas tank down that with the fuel sloshing around uptop like that would cause top heavy problems, and that the rudders need to be made of a thicker material, we are using a pushpull setup on the rudders with a rudder link but read that since that sign is such a flimsy thing that with the power the 16x10 prop is pushing out it is also buckleing on us. Any advice or info would be great. Soon here we are going to buy a new motor 99% sure from someone here on the forums as there are some great setups that people have in the For Sale area but for that motor we are going to build a nice hull for it. The board is only 33"x16" I have a feeling it is way to narrow and short that is a lot of motor to put on something that small I feel. At this time the servos and radio box are removed we were trying to dry them out to maby salvage the servos it did not work.

We have read through a ton of posts and all and we know we got a lot to do, but if anyone sees anything that could give us more stability from this please let me know.

Thanks for taking the time to read, and reply all is greatly appreciated.

CTSmithey

dadkins

Nice I like the leaf motif... and ya get that gas tank DOWN. I have made a few weedeater bikes in my day and Like the Ryobi's they pull pretty hard and are super reliable.

CTSmithey

My Feedback: (2)

I just can not believe how that motor has held up, we have seized it 2x from running to lean no oil was sticking to the motor, then I flipped her 2x 2nd time was worst tho, it was upside down for the better part of 20min, got her on the dock dumped out the water fired rite back up again. It is really fun on grass, but the water it just flips over in the turns. Makes me so frustrated lol.

The main thing is we are learning and it really is a blast. Just stinks you get 20hours work time, and 10min total because of me and my flipping issues.

EDIT: I forgot to add this, since Ryobi now MTD likes to make sure fuel lines are specific to them, they do not expand or shrink also a strange size, should we plug the holes at the bottom of the tank, drill ones in the top when we move the tank to the deck? Then we could use what is it called? Tygon fule line? and put a inline filter in correct?

dadkins

Have a small engine supply near that has about 4 differnt sizes of the tygon that are less than 3/16 id

DJLaPalme

I hate to say this but I believe your boogy board is too small and lite for that size engine. You should be close to 40"s or a little more in length and close to 24"-26"s wide and close to 26 lbs. in weight. Nice first try. You could get a .46-.60 size nitro motor and that would probably work great. Have fun and good luck. We have a group of r/c airboaters that used to meet every month in Ocala and we are hoping to get running again after the first of the year. Bring it out and we can help you get it right. Dennis

CTSmithey

My Feedback: (2)

That would be great, we have been looking for some kind of RC boat or Airboat club, or just people that have them in our area and could not find a thing. It is harder looking at images or getting advice over a PC than to walk in, show what you got, see what they got and ask direct questions. If you guys do get back together please put me on a list to notify. We greatly appreciate it, and yea it is way to light that boogie board is one of the Wham-O ones that is so light I am suprized the motor weight and pull has not snapped it in half yet. I can tell ya this tho it hauls butt lol!

CTSmithey

Altered1

This is my boogie board build. The new mount, with a ASP .52 2stroke Nitro. First version (blue) was an Enya .60 (bottom). .... I just realised i dont have a shot of the current mount on the board.... on the to do list.....

The ASP cost me $55, the servos cost me $5 bucks each, and I build the mount from scrap ply. This is mounted on a foam body board 40' long, and about 21' wide. I got this board from the local cheap store that sells everything, for 20 bucks...... Coated the mount with fiberglass resin.

you're over engined, and balance is a bit far forward, and top heavy... combined with a small hull..... Great first effort though!

You want the weight balance point about 1/3 of the length from the rear of the hull, and as low as possible.....

CTSmithey

My Feedback: (2)

Yea with that 16x10 prop we can not get her much lower. We tried a 14x8 on it, but the motor was just spinning mad with little thrust to move it. I would love to just find a hull that someone built and buy it, I am so frustrated at this point with this whole thing. I can get my hands on a 45" bodyboard but still feel that it would be to light for this motor, and I am getting ready to either build up a 33cc Poulan Weedey, or a 42cc Poulan from my Chainsaw.

Does anyone know where I can just buy a prebuilt hull? Maybe a 42" somewhere? I searched the web and can not find anything other than plans, I got tons of plans just do not have the time to really "build" a hull, nor the tools so buying one built for a weedy 31cc+ is what we want to do, staying away from Nitro Motors to expensive for fuel. I am disabled so is dad so we do not have a ton of cash to throw around. Just trying to have a little fun and all that good stuff.

1QwkSport2.5r

I do not know the dimensions of it, but you could use one of these: [link=http://rcairboats.net/page3.html#SI360]SI3-G Hydro[/link]

Its a 1/4 scale 3-point hydro designed around using gas engines. I dont have one myself, but a lot of guys do and you can get one in Kit form (laser cut) or pre-built. You would have to email or PM "Selph Inflicted" here on RCU to get pricing info, and shipping time. The glow kits are available anytime, but the Gasser kit is special order.

From what others have said, the kits are very easy to build and are of good quality materials.

CTSmithey

My Feedback: (2)

Thanks 1QwkSport2.5r going to send that info to my dad and see if he wants me to do just that. Heck, we prolly could afford the kit and just build it our-self at that point. That would be great! Thanks tons. Still tho, them are pretty rad designs wanted something more like an airboat, but if that is all there is then it is fine by me just gotta see what the old man says haha! 40years old and still confiding in the father I hope my 2 kids are like that.

1QwkSport2.5r

There aren't a lot of kits or even pre-builts for gas engines. Most of whats available (like the Dumas Big Swamp Buggy for example) are all designed around smaller glow engines .40-.60ci or so. I just know the SI3 kits are top notch quality and are a proven design. No guesswork if its going to float or run or not. The 3-point hydro is aimed more at speed, so if thats not your thing then maybe the SI3 kit may not be for you. There are other gasser airboats available but the costs are probably higher due to more detail being added (like a fan cage and small seats, etc).

CTSmithey

My Feedback: (2)

I hear ya, I went ahead and PMed Selph and asked him about the boat and price. Thanks again for the info. It seems we went from "Hey, this should be easy" to OMG! lol but we are addicted now and do not even have a real run time yet at all.

1QwkSport2.5r

I've been a car guy for 15 years (maybe 16 now?) and for a loooong time I never thought I would want a boat. Mainly due to the fact if (since I'm a glow-only guy) it stalls on the lake, your S.O.L on getting it back "easily". Then I got some free airplane (glow) engines from a friend and decided to build an airboat. For similar reasons to boats, I didnt want to fly a plane though that was based on a fear of crashing it. I now have 3 airboats that are built, and 1 more on the building board right now. I also plan to buy a plane sometime in the next 6 months also.

I think the RC hobby is a can of worms for a lot of people. For me, I just love everything about small engines. The noise, quirks, smell, and power.. It just amazes me how something so small (and coming from fullsize auto shop mentality) can run without piston rings... Seemed crazy to me at first.

It can be a lot of fun. I love the RC hobby. When I take my fullsize fishing boat out, I bring one of my airboats with for when the fish don't bite, plus its an easy retrieval vessel.

BTW: there's a strictly airboat forum on that SI website, also. If you want some other ideas of what people are building/have built, check out the forum.

CTSmithey

My Feedback: (2)

Yea I signed up on the forms there but never got my final email from them saying I was accepted, I got one saying there was one more step a moderator or what ever had to give a final approval and that was the last I herd of it. That was like a week ago, when I PMed Selph I told him about that as well.

My dad wants to try out some 4x4 trucks he likes those as well, me I am more into Airboat/Heli/Jet so figured the way to get the basics down was doing this Airboat project for a learning curve and it has proved to be useful at the same time makes you want more and more. I am going to end up building a wacked out Airboat I know I am. I have been sitting here today staring at a 14.5HP Briggs motor that is all setup for Gokart Racing and my mind was wondering hmm, prop size, boat size lol.

1QwkSport2.5r

Its been slow over there lately, I imagine Chris has been busy (Selph Inflicted/Admin) too. Its a good place - the members are well mannered, and many of them are quite experienced..

14.5hp Briggs, eh.. Thats big enough to build a rideable airboat. You'd probably need a 28" prop which costs a bundle, but it sure would be fun!

CTSmithey

My Feedback: (2)

Yea a rideable one would be ok, but leaning more to RC hehe. I know it would be huge but if we can get things going and come into a little more cash than we both get a month to play with we will see how that project pans out. I went to the forums there a few times to read and learn, also PMed someone from there but had to do it from YouTube lol! I know XMas season has everyone busy busy! and it gets more hectic every year for everyone.

Dockrat

how do you mount the engine to the board with out crushing the boogie board, some kind of coller with nut and bolt

CTSmithey

My Feedback: (2)

What we did was just use carrage bolts going through the bottom with large flat fender washers on the bottom as well, then filled the holes with Liquid Nails for Foam and Panel let it set and dry, then came back the next day drilled the holes in the 2 LChannel Aluminum pieces and used aircraft nuts to lock it all down. After it is in place you do not have to move the rails again, to move the motor forward and backward to adjust for the 1/3rd balance point toward the rear. It worked really well for us never had a problem, and that poor boogie board went through heck and a half lol. Wrecked a few times on ground, and wrecked HARD, flipped a few times in the lake, smacked into a couple of docks and walls lol. Held up amazingly well for just being a cheap-o boogie board. We just had WAY to much power for that small board, we should have went to a 41 to 44 inch board not a 31 to 33 inch.

Altered1

Hey Dockrat,

with my body board build, I epoxied some 1x1 inch pine rails into the deck of the board. I went across the direction of travel. I should have gone along the board instead, but nevermind, she still works well. the COG mark is 1/3 the length of the board from the rear. this is optimal balnce point for flatty airboat with all kit loaded.

I just screw my deck into these rails. If I need to move anything back or forward for balance, it's only a couple of screws... works well for me. You may want something more permanent though.

Dockrat

Thisis one of my finished boards. I also build air boats out of foam that you would use under the siding of a house

CTSmithey

My Feedback: (2)

Nice looking Boat there Dockrat! You should also come over to www.rcairboats.net and join the forums there. That is all we do over there is Airboats

You can follow the link in my Sig for the build that my dad and I did, it is also here on the RCUForums as well, but more info and other good stuff is on the Airboat one.

http://www.rcairboats.net/phpBB/inde...0134d7f3476a53

That should get ya over there, get signed up and join us for some Airboat Goodness!

Here is how our 1st real build came out, it is all foam core like you said you work with as well, with wood over and epoxy ect. Runs a 32cc MACChainsaw engine.


This one is after we got a larger tank and did a few other mods to it, this is how we still run it, have not had the time or spare cash yet to put a cage around teh prop lol we are slacking.


If you want to see her running you can go to my YouTube Channel as well, there are also motors we have modified some that we have sold for Airplane and Airboat use.
http://www.youtube.com/user/GMKosMos?feature=mhee

Stiltman0287

Another thing is you have to make sure your rudders are only from the bottom of the prop to the middle of the prop cus if when you turn, the rudder pushes air sideways on the top, it will flip the airboat. But if it's only pushing on the bottom it won't.

Got RPM

Stiltman, it is a nice thing for you to offer help, but this thread is five years old. The OP hasn't posted in five years so he can't read your suggestion.



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1QwkSport2.5r

I knew the OP from RC Airboat world. His wife had stage 4 cancer and passed away several years ago. After that happened, he dropped out of the hobby and didn't post on any of the forums anymore. He was a swell fella and I hope he is doing well these days.

FWIW, I have NOT heard that having the rudders extend above the centerline of the prop to cause any stability issues. Typically one will get more than enough steering thrust from the rudders if they are at or below the centerline of the prop.