Hello,i am building a 1/2a simple series piper cub,i just got some stro floats 11.5 inch's long.i am using a tt .07 for power.my questions is,do i need to build a water rudder? or can i just use the rudder from the plane for steering. Thanks

Many people find the water rudder "useful". It's not mandatory. If the motor is running, prop blast over the air rudder can be used to steer the plane. If the motor is NOT running, it doesn't matter.

thanks, i might make a water rudder,trying to save weight ,tt.07 does not have a lot of power.thanks again

I think your floats at 11.5 inches may be a bit on the short side. I'm not sure of the fuselage length of the SS cub but a gereral rule of thumb is for the floats to be 3/4 the length of the fuselage and this is for larger planes. For a 1/2A size I would make them at least that length or a bit more. The only successful 1/2 A seaplanes I have seen are the flying boat type like the Aqua Star.
Good luck

If you are only flying in calm wind (which is probably the case with a smaller plane) then you won't really need the water rudder. Having said that, it doesn't weigh much if you do it right (pull-pull from the air rudder using fishing line works well) and it will be much easier to taxi on the water.

the fuse length is 25.5" PETERC i am glad you said something i would hate to sink it before i fly it.i would like to make the cub water ready.how would i make some light floats for it.or could i order some if so were.weight of plane ready to fly is16 to 20oz+.any help would be great.THANKS FOR THE HELP.

I would consider this close to a 1/2A; this is an electric Speed 400 size plane (Scorpio Threedee 400) with foam floats. Both the plane and floats were purchased at Hobby-Lobby. The floats are made by Kavan for the "Wingo," and are very light, but pricey at $40.

I installed an OS 10 with 7X4 prop and it flies perfectly. It will take off on water OR snow in about 30 feet, and will fly for about 7 minutes on a 2 oz tank. It is great for local parks or schools . . .

Plane's dimensions:

Fuse length: 30"
Float length: 19 1/2"
Wing span: 36"


No water rudder, and best in calm wind.

Another:

Lets see,..... 25" fuselage length X.75= slightly over 18" length. This is not an exact science, but 18" is a lot longer than 11.5".
I also have an old set of those floats you have. They were made by Cox for a 1/2A control line cub on floats and I too have been eyeing them for an application. Right now they are going to be the tip floats on a 2X25 seaplane I am designing. I think they will be about right for that application; especially since length does not matter here.
If the Kavan floats are too pricy as mentioned by mpowrmnt a foam, flat bottom square cross section with the step under the CG will work. Use the profile of the floats you have as an approximate guide for the profile cross-section. Glue strip of spruce in a groove along the top edge to screw the attachments to. Floats should be RIGIDLY mounted. This means no flex. No finish is required but you could paint or cover them with an iron on covering. Epoxy will weigh too much.
Another rule of thumb is that one float should have enough bouyancy to support the entire weight of the aircraft. Look at photos posted elsewhere to see what others are doing.
I think I'm running out of thumbs.
Keep us posted.
Peter

THANKS for all the help! the wingo floats is the way to go. (mpowrmnt) good looking plane.40 dollars is not to bad.(Peter) Thanks i will post pics when i get it done.

hey ,been working on the cub,have the fuse done.but the landing gear is to small i think.the floats are only 3in apart and the fuse is about 2 1/2in from the top of the floats.how far apart do they need to be? and how high does the fuse need to be? i got the wingo floats.any help would be great. THANKS

Dion,
to keep the prop out of the spray from the floats, put the bottom of the prop arc around 1 1/2" higher than the top of the floats.

The rule of thumb for float spacing is 25% of wingspan.

the step of the float should be under, or slightly behind the balance point of the plane. Also, there needs to be some float sticking out in front of the prop, both for stability and to keep you from striking the prop on stuff when taxiing.

The floats should be lower in front than in back. Another way to say it is with the top of the floats level, the wing should point upwards a bit with a Positive angle of attack of 3-4 degrees.

If you do rig up a water rudder, don't make it stick down very far. It is used for taxiing. You want it well clear of the water when you're up on step trying to take off. If the Water rudder digs in, it'll cause enough drag to keep you from hitting takeoff speed.

THANKS for the help everyone!!Could not have done it alone.i will have to make some gear for it.What do you think of using lexan for the gear.heat it up and bend it the way i need it.need something light,if you know someway else let me know.THANKS again

Lexan is so expensive you'll probably be the first to use it, but if you have some it should make a nice set of struts. Be sure to use spreader bars between the floats to keep them from "dancing". Unlike wheels or skis, float mounting should be as rigid as possible.
If forming the lexan doesn't work out, traditional wire mounting can be assembled from bent pieces. For a half-A plane, you could use 1/16 or 3/32 wire.

Try looking at www.foamfloats.com I have the 16" on GWS tigermoth, 19" on the GWS beaver (15.5oz all RTF) 30" on Kavan Partenavia and working on putting a GWS Zero on a single float. Prices are good and service has been GREAT, plus, if you mount these on a plane that has not been done yet you get the floats for free !!! Check the web site for details and tell Will I sent ya.

Leonard Perry

i am going to try the lexan,i will post some pixs of it when i'm done. thanks for the info

AKFLYER,

If you could, please give us a photo of the tigermoth on floats. How does it fly? Did you have to change the motor. I have one, as well as a buddy of mine, it just seems that the weight and drag would be an issue. I live on an island and would love to have this plane on floats.

Perry Beebe

Here are a couple shots. I am using the stock motor and an 8 cell 300 nimh. I have also used the 2 cell b830 qual coms and she flew great on them just not quite as much power.

twins

10.0 oz RTF.

AKFLYER,

Thanks for the info and the great photos. I might buy another tigermoth for this project because I really enjoy doing touch and goes on my driveway almost every afternoon.

Beebe

it takes less than 30 seconds to go from wheels to floats so you really dont need two !!!!! You will love playing with this on water. I can get it off mud puddles that are ~10' long.

I figured it wouldn't take long. I would just like another excuse to tell my wife "I NEED ONE MORE PLANE". My current tigermoth has been in a couple of trees and my 2 year old son got his hands on it several times. With all the packaging tape, the plane is not very attractive anymore. I just need another.