Hi, this is my first boat build. Not sure what exactly the material i used for the build is called, but i know it's commonly used for building scaled down models of buildings. Planning to throw in a bunch of my aeromodelling stuff into this boat and make it run as an air boat.

Congratuations! You are using Sunboard -what scale, what size? If you are building it to a plan, please point (link it here) it out for us.

Regards.

more pics

Quote from: VC on June 26, 2013, 01:42:37 AM
Congratuations! You are using Sunboard -what scale, what size? If you are building it to a plan, please point (link it here) it out for us.

Regards.

thanks for the info.
Not referring to any plans, built it today after a quick look into google images
the boat is 500mm in length.

till this point, a day's build.

GREAT spirit and attitude. Welcome to the forum! Keep us posted.

Quote from: VC on June 26, 2013, 01:59:05 AM
GREAT spirit and attitude. Welcome to the forum! Keep us posted.

Thank you

Great show Anjan! It looks really good.

Will follow your post and wait to see it sail

All the best

Hey anjan nice hydro
Dont you think a hydro is a bit too much for a first boat
And it being a hydro i think you will need quite a bit of reinforcements on it if you plan to go race class.
May i ask what is your power system and AUW?
Awesome build man

Quote from: sanjayrai55 on June 26, 2013, 06:52:18 AM
Great show Anjan! It looks really good.

Will follow your post and wait to see it sail

All the best

thanks a lot, Sanjay! might take a couple of weeks beofore i can make time to finish it and do the testing, hopefully it's all waterproof.

Quote from: RCNeil21 on June 26, 2013, 07:32:14 AM
Hey anjan nice hydro
Dont you think a hydro is a bit too much for a first boat
And it being a hydro i think you will need quite a bit of reinforcements on it if you plan to go race class.
May i ask what is your power system and AUW?
Awesome build man

Thanks man
the hull is 70% completed and weighs about 190g currently. expecting it to be around 250g fully finished without electronics.
w/all electronics expecting it to be around 400-450g
i have a bunch of aeromodeling stuff, going to run it on a 1400kv motor with a 7'' or 8'' prop as an airboat.

Post a video when you are done. I love airboats!! Is this your first airboat? If so, then you should make sure that:
1) Your CG is as low as possible. Otherwise it will go upside down quite easily
2) Keep the C.G. at about 30% of the total length forward from the transom,i.e., if your boat is 100cm your cg should be within 30cm measured from the back.

Quote from: lastRites on June 26, 2013, 12:05:09 PM
Post a video when you are done. I love airboats!! Is this your first airboat? If so, then you should make sure that:
1) Your CG is as low as possible. Otherwise it will go upside down quite easily
2) Keep the C.G. at about 30% of the total length forward from the transom,i.e., if your boat is 100cm your cg should be within 30cm measured from the back.

yes, this is my first air boat. thanks for the info, appreciate it.
the 30% CG point is to keep the nose from lifting off?

You can say that.. The way you mount the motor is crucial. That determines the perfect cg point for your boat. Since you are building your first one, I suggest you make provisions for a adjustable motor mount. If its a pusher your motor needs to point up a bit. Point a bit down for a puller. You need to play around with the angles to get the perfect balance between speed and stability. Try and keep the propeller at the C.G.
AND post a video when you are done

Quote from: lastRites on June 26, 2013, 01:03:55 PM
You can say that.. The way you mount the motor is crucial. That determines the perfect cg point for your boat. Since you are building your first one, I suggest you make provisions for a adjustable motor mount. If its a pusher your motor needs to point up a bit. Point a bit down for a puller. You need to play around with the angles to get the perfect balance between speed and stability. Try and keep the propeller at the C.G.
AND post a video when you are done

sure, but right now the back end seems to be a bit heavier than front, even with all electronics put as far front as possible.
what  if i have a more-than-30% cg and increase the angle on the prop, will that compensate the rear end weight?

i'm planning to go for the pusher setup as i'm using a prop adapter that could be dodgy, so dont want the prop to fly away in a puller

also, is it okay if i use in-water rudder? i could build a rudder behind the prop though.

Build almost done. Have to make extension for motor wire and check for leaks in the hull for one last time tomorrow before some paint and decals go on

...

...

Very interesting motor mount and position. I had expected a cockpit in the front and a normal prop in the rear or mounted on an extended boom in the front. Hadn't expected a pusher. Will be waiting to see her sail.

Quote from: VC on June 28, 2013, 11:38:55 PM
Very interesting motor mount and position. I had expected a cockpit in the front and a normal prop in the rear or mounted on an extended boom in the front. Hadn't expected a pusher. Will be waiting to see her sail.

i could conveniently house everything inside the hull and I'm not that much into scaled details, only functional, so no cockpit.

pusher setup because i've always felt a bit insecure about those prop adapters, i dont want it to loosen up and the prop fly away; in pusher, the prop would be pushing against the motor so, slightly safer i think.

motor mounted up front because CG was at close to half the length, so had to put some weight up front. even the pins are made of depron to save weight

will be testing it this weekend hopefully.

All the best. Ensure that you videograph her maiden for all of us to learn. I had started building a similar boat but then an over enthusiastic visitor stepped on my hollow Depron sponsons and destroyed her. Haven't had the heart to throw her away. Hope to rebuild her someday,

Quote from: VC on June 28, 2013, 11:56:12 PM
All the best. Ensure that you videograph it for all of us to learn. I had started building a similar boat but then an over enthusiastic visitor stepped on my Depron sponsons and destroyed her. Haven't had the heart to throw her away. Hope to rebuild her someday,

i know about those ''over enthusiastic'' people, they usually ruin my servos while trying to move them by hand

i'm going to meet Akash, a fellow boad builder i met on here, just hoping everything to go well, if not great.

my boat's AUW is close to 800 grams now, is that too much? the motor produces 1010grams of thrust in my setup. 

800 gms versus 1010 gms sounds pretty good for a first air boat, IMHO. Let the experts comment and guide.

Your motor position is interesting I have seen front mounted pullers, the fastest airboats use that setup. Just do one thing. After you have installed everything, pick up the boat by putting a finger under the motor shaft between the prop and the motor bell. The rear of the boat should hang lower. Start off with zero thrust angles. Run the boat. If you see that the nose dives on throttling up, move the CG back and try again. Best of luck

Quote from: AnjanBabu on June 28, 2013, 11:49:51 PM
motor mounted up front because CG was at close to half the length, so had to put some weight up front.

Your CG SHOULD be behind the half way of the hull. I never had to put any weight up front..