Air Boats Anyone?

[larryb]

Looking for some ideas on building a air boat (aka swamp buggy). I have some 2" epp foam and have got the hull design done but cant make up my mind to make it a pusher or puller. Hull has a 10" beam and length of 24". Plan on using a .15 or .25 to power. Am wondering about the CG of the boat. First float test of the hull tells me this will be a very light boat. Also, any ideas or suggestions on placing a skeg on the bottom to help keep it straight? Does angleing the engine up or down to help trim the boat for flat travel help. My thought on this was to add a trim plate on the transom and use a servo to trim it.
Hey, any help would be great. sock your ideas to me!!

Larry Barnes
www.spudgun.com

[Merlin]

I would set the thrust line at 0 degrees (or parallel to the bottom of the hull. You can always use washers or a wedge to adjust the thrust angle after testing. I wouldn't think you would want a positive (up) angle though, as this would tend to lift the stern up and bury the bow.
And instead of a skeg, I would use full length strakes on the bottom of the hull to keep it going straight.
Tractor or pusher? I would use a tractor setup.
Good luck

[larryb]

Thanks for the info. I built the boat and gave it it's first test yesterday. Your suggestion of parallel thrust was what i used. didn't have a skeg and found it was kinda hard to keep in straight line. I had thought of making a tunnel hull to help keep it straight. Anyway, had a good time the OS .35 with a 8 x 6 prop didnt make it as fast as I thought it would be. Didn't have the bow lifting that I thought I would. Worked great untill it fliped over on its side. had to drain the water out of the engine and had it back on the water in no time. The complete boat weighs just under 2 lbs and draws only 1/8" of draft.

Larry

[cathode]

I like Airboats, can you show us photos? :D