nickd

I am looking to build a electric airboat, I have just ordered a 3 cell 2200mah 20c lipo (funny that the boats being shaped around a battery)
I bought the batt to go with a small outrunner motor so far thinking this https://www.unitedhobbies.com/UNITED...idProduct=4712
or anything else under about $30 for the esc and motor)
I was thinking foam would be easier then wood for a first build but am open to suggestions.
If you guys can help suggest size or plans or anything it would be helpful as I really have no idea what I am doing, I just know I want to do it ha ha.

Selph-Inflicted

What style of boat are you planning on building?

I'm not much up on the electrics but will give you a suggestion.

When I build a flat bottom boat, I build it around the prop. The top of the deck is generally a few inches wider than the prop being used. My boats that swing a 11" prop is 12" wide on the bottom and 16" across the top. For the length, a ratio of 2 to 1 is a general rule for that.

Keep this in mind. There are no set rules for an airboat. The best thing to do is get a general idea, build it, then tweak it. After you build one....your gonna build another.

Glad to see you have the "Airboat Bug!!"
Keep us posted.

saleens7

i would go with foam....i would make a hull around..11" wide by 22" long by 2" thick....i would make 45" angles on the sides of the hull...round them out a bit when the side of the hull reaches the bottom....this will help the hull from catching a wave in a sliding turn and flipping....i would coat the hull in a coat of epoxy resin (maybe a 2nd coat on the bottom of the hull)...dont use poly resin, it melts foam....

nickd

really that large of a boat with a small setup? (is that using the motor in the link or something else?)
Where do you find epoxy resin? and do you also put fiberglass in that or just resin?
Thanks for the help

saleens7

well...maybe you could decrease the size to 20" by 10", but to make 45* angles on the side, the bottom will be a total of 6" instead of 10...you could leave the sides at a 90* angle and just round out the bottoms though...that way the running surface will still be wide...since most of the weight (batt) will be on the hull instead of up on the motor mount, it could be smaller and still have good stability.....

but yeah, those little BL motors do have a lot of power to them...someone used that same setup on another boat and i think they got 600 grams of thrust from it...

nickd

Selph-Inflicted
Some how your post just showed up, thanks for the advise and info
As far as style I have no idea, I want to run on grass water etc.

Saleens7
I just realised the decrease in size because of the the sloped sides and nose.
I will take your advise of keeping it wide I really dont want to flip!
Yeah I have heard the brushless do have a lot of power the one I am looking at has I think 800 grams of thrust, being a car guy I have no idea what that means.
The other motor combo I was looking at (double the price) was 32oz of thrust would that be better?

Thanks again for the help, if anyone else wants to add input all is welcome, I still need building instructions which should be the same nitro or electric

Selph-Inflicted

Go with a flat bottom boat. It is the "all around" boat. You can run dry and also play in the water with.

What size prop are you gonna be swinging?

saleens7

https://www.unitedhobbies.com/UNITED...idProduct=4712

he'll be using a 9x4.7 prop...

nickd

actually I haven't chosen the power source yet, I am thinking one of the 25amp combo's from united hobbies I am not sure which one of these is the strongest, I want to be able to do full power for quite a bit so I don't want to have a prop to be big to overheat anything, which one out of these is the most powerful. https://www.unitedhobbies.com/UNITED...idCategory=179
Or is there another set up you would suggest I can order separates.

nickd

hey salleen I was just reading your thread and your boats coming along, what do the steps on the bottom of the boat do?

Selph-Inflicted

Steps on the bottom reduce the "wetted surface" that the boat runs on, reducing water drag.

nickd

so would you then suggest be adding that to mine for running on surfaces other then water, which would take advantage of the lower surface area generating friction.
Does it reduce stability at all?

nickd

Alright I ordered a bunch of stuff this afternoon including my motor and esc combo with a prop, This is what i got
https://www.unitedhobbies.com/UNITED...idProduct=4708
apparently it can do 800+grams of thrust
I also bought a breakaway prop adapter (the thing that attaches the prop with an o-ring so I can play around with prop sizes
Now that I know what I am running, and I will have a 9X6 prop how big should this boat be? (wide so I dont flip in the water)
I also bought some foam glue, does anyone have a link to any tutorials in making foam hulls?

TERBObob

My Feedback: (21)

Wrongo ...
Steps create AIR bubbles/pockets under the hull ... thereby creating a "lift" effect .

Tommy gallagher

Nick here is a little better explanation on the outrunner you just bought>

Actually its a pretty good one and your boat should be screamin. Also there are a couple other prop combinationas listed there so read on

http://cgi.ebay.com/2409-12T-Outrunn...QQcmdZViewItem

Tom

nickd

Thanks tom I will have to try the other prop combo's, I am afraid I will blow the esc as it is only a 25 amp one and alot of those props draw 22-23 amps []
Its funny I had looked at that motor on the ebay sellers site and never realized that I had bought the same thing.
SO what size are you thinking now that you know what I'm running?

airpuck

hey when that combo comes and you use it can you tell me how strong it is im thinking about geting it but i dont know if it will power my 23 inch long basswood boat. its sortof on the heavy side

nickd

yeah sure I ordered it yesterday so it will probably be about 2 weeks till it gets here (China to Canada) but I will be sure to tell you what I think of it. Mind you I am not very experienced.
I read in the link above that it can give 32 ounces of thrust which is equal to 2 pounds so as long as its less then that it will have a 1-1 ratio of power to weight.
Can you post a pic of your boat and list the demensions, sounds like about the right side for what I've been told to build.

airpuck

i made thread its called some thing like ---1st build (w/pics) its a couple down on the mane list in airboats