what do you guys think of this? i want to build a 30 inch by16inch gas boat. only one problem. i don't know if it should be a pusher or a puller and what kind of engine could get it going fast?

Do you have an engine ready and waiting? If not I would use a smaller chainsaw engine and have a pusher, but that's just personal preference. With a chainsaw, you can have a pusher configuration but still use regular props (using the intended ouput shaft on the saw), allowing you to have a wider selection of props to choose from. afixing the prop sometimes can be a bother with ALL gassers, There are people out there who sell ready made prop adaptors for weed eater engines, but I've never seen one pre-made for a chainsaw.

For ease of starting I usually leave the recoil on. No need to lug around a starter motor and a battery, although the recoil does add some weight to the boat.

Hope this helps.

how many cc's does it have??

if its 24cc's or above, i would consider making a bigger hull (shaun made a hull with similar proportions and had a 24cc engine, adnd it had a bad tipping problem)

when you said gas engine, did you mean a gas engine, or nitro engine?

a lot of people un-familiar with nitro engines mistake then for gas engines

either one. i just want the fastest boat possible.
last night i drew up designs. i think it will be a medium weight but i don't know for sure yet.i think ill build mist of it with 3/32in. ply and a few [pieces with 3/16in. ply. do you see any problems with this. 1 last thing. i change my length to 31 in.

then a .46 or .40 it is (nitro)

gas enignes are too big. someone built one about that saze and it had a severe tipping problem

and if this is your firstt build, i would suggest have a somewhat slower (about 20+mph) boat to get used to running, airboats dont turn like water propped boats, they slide into the turn, and have a relitively larger turning radius...

this would be my second boat after my electric
. technically my 3rd if you consider my old plane engines slapped onto Styrofoam.

sry but i have another dumb question.is it hard to hook up your radio to gas engines and how.also what do you use for speed controls?

no, its not hard, just do the servo linkage to the carb

no speed control, just hook a servo up where the speed control would be....simple...and the questions not dumb, what would have been dumb if you never asked it and tried to find where the speed control hooks up to the carb

you will need some pushrod though, and if you dont have one, a Z bender to kae the notch in the pushrod so it will hook up to the servo and carb...

ill try to find a pic of an airboat setup to give you a better idea...

here ya go, it shows the servo to carb linkage on my .40 engine test stand (thanks to asmithnc for the stand)







the Z bend makes the small bend in the wire to get it to fit through and stay in the servo horn and carb's throttle

ok i admit it was me with the tipping problem.

ok you need some serious help

first of all join the [link=http://rcairboats.net/phpBB/index.php]RCAA Remote.Controlled.Airboat.Accosiation[/link]

then have a chat to hooty301
if you want a REALLY FAST BOAT that climbs up walls and goes nuts [link=http://rcairboats.net/phpBB/viewtopic.php?t=168]look here for the plans[/link]
[link=http://www.youtube.com/watch?v=BIRLdS2nAXw]and here for a video of it[/link]

we have plenty of people on RCAW that can help you (Beware of the Big'n though lol)

so there you go, all the help you need.
shaun

what thickness of wood do you think i should use on the hull?

i dont think you should use wood at all....

make the hull from insulation foam, then fiberglass over it...but when you fiberglass, use epoxy resin, not the polyester resin, that stuff eats foam...

foam is easier to work with as you make the hull from a solid block, its lighter, and it floats already, no need to worry about flotation....

maybe the only peice of wood you might want to use is where the motor mount will be, just to have a solid base to attach it to..

my current boat is out of wood and it floats great but its a little heavy i no i could make one lighter though.

hiiiiiiiiiiiiiiii[>:]

err ....HIIIIIIIIII[sm=bananahead.gif][sm=punching.gif]

so any build progress? evem start yet?

havent started finishing my elictric

Saleens dont discourage the kid from using wood or balsa you never know what he likes!!! or how good of a builder he really is!!!

Althought foam may be easy to build with, but wood can be a much more creative way to build with and lighter if build right it all depends on the structure of the model.

Maybe you have never actually attemted to build with wood!! Ha what maybe[:'(]

If your looking for speed and control, you don't want the boat too lite. Not haveing enough weight will cause more problems, more so on the flat bottom hulls. Basic weights .40 nitro 7lbs. .46 nitro 7-1/2 to 8lbs. .61 nitro 8 to 12lbs .90 nitro 13 to 16lbs 1.4 nitro 14 to 18lbs 27cc gas 20 to 30lbs 42cc gas 25 to 32lbs. This is appx. weights for flat bottom hulls.

Mr Cajun Gator, those approx weights have me a little worried , i know my airboat is not technicaly flat bottomed (flat bottom cat?), but its using a .61 super tigre, and the whole thing only weighs around 3 lbs. I`,m not quite finished building it, take look at it in the link, you might be able to give me some ideas ?? as i know you know a lot about airboats, perhaps some weight might need adding??
http://www.rcuniverse.com/forum/m_5220872/tm.htm
Rick
[sm=thumbup.gif]

thanks guys for every thing and ido like to use wood because i can make my sides the same.

saleens why cant i pm you??????????????????????????????????????????????? ???????????
did you block me???????????????????????????????????????????????? ???????[sm=punching.gif][sm=cry_smile.gif]

so have you started cutting that wood yet[sm=confused.gif][sm=thumbup.gif]

no cutting yet just finnishing very end of my elecricd bad airboat. i say bad cause i dont think its that good of a design but its good for no help and not even a teenager.