AP Kwak - the Mighty Mini Foam Board Mod of the Jupiter Duck

[Wingnut pilot]

dang and I even cut that part out lol. just some radio stuff to finish and pick a good day for the maiden! the other two I cut will be built by friends.

 

[Sero]

Built myself a little Kwak. My first non FT FB plane. Weighing 250grams with servos only.
Waiting on a motor, hopefully get to fly it this weekend.

 

[checkerboardflyer]

The Kwak assembled and waiting for the Minwax treatment.


View attachment 88835
Will two coats of Minwax seal it up enough to run on water?


View attachment 88836

Really nice job. Clean.

 

[durban_]

Thank you! I am also working on civil airplane decals.

Hi!!! finally have something civil?!? thanks!!

 

[durban_]

Hi everyone!! this is my model building... to be continued.

 

[AircPirateNinsei]

@durban_ I won't be home for the next two weeks and I don't have the AP Kwak files with me. If you're patient, I'll send you the decal file in two weeks. Thanks for your interest.

 

[AircPirateNinsei]

@durban_ I have sent you a PM with the download link:

 

[Timmy]

This is such a "cute" plane . Definitely putting it on my list of things to build!

 

[wrangler90]

Can anybody share information on if they had any CG Issues; and how they compensated for it being tail heavy? It appears from my build a considerable amount of weight is needed. I'm using a 3 cell 850 all the way forward and 90 degrees to the fuselage. I already moved the motor forward with the nacelle plan addendum.

Is what I just described normal for this plane?

I have not attempted the maiden flight yet as I being extra careful not to damage it before I check with others first. My RC Club has a float fly this weekend and this will be my first opportunity to fly off of water.

 

[AircPirateNinsei]

@wrangler90
How many grams of extra weight do you need in the nose? What does your battery weigh? If you have a CG-scale, please put the Kwak on it (ready to fly) and take a picture of the side for us.

 

[wrangler90]

@wrangler90
How many grams of extra weight do you need in the nose? What does your battery weigh? If you have a CG-scale, please put the Kwak on it (ready to fly) and take a picture of the side for us.

2 ounces of wheel weights work. not sure on battery weight as I do not have a scale but the battery is a 3 cell 850 and it is all the way forward. ill send a picture of the side.

 

[wrangler90]

 

[AircPirateNinsei]

It looks like the heavy white foam. If you don't have a scale, then you can't check the weight of one sheet of foam and you cant check the all up weight (315 g | 11.11 oz) of the plane. The only thing you can do is to check the center of gravity with two fingers again. It is 50 mm behind the leading edge of the wing. It is also marked in the plan. I hope that your Kwak will not be too heavy for the first flight. Have fun!

 

[wrangler90]

It looks like the heavy white foam. If you don't have a scale, then you can't check you cant check the weight of one sheet of foam and the all up weight (315 g | 11.11 oz) of the plane. The only thing you can do is to check the center of gravity with two fingers again. It is 50 mm behind the leading edge of the wing. It is also marked in the plan. I hope that your Kwak will not be too heavy for the first flight. Have fun!

Thank you.

 

[mejonas]

My first attempt at flying the kwak, I could not get airborne. So I burned a battery just water skimming. It’s been just sitting in the garage since then. I was building a replacement simple cub and got to thinking. Below is what came out of that. A kwak with a simple cub wing. It looks so cool that almost don’t want to fly it, but I will.

 

[Wingnut pilot]

 

[mejonas]

My first attempt at flying the kwak, I could not get airborne. So I burned a battery just water skimming. It’s been just sitting in the garage since then. I was building a replacement simple cub and got to thinking. Below is what came out of that. A kwak with a simple cub wing. It looks so cool that almost don’t want to fly it, but I will.
View attachment 230279 View attachment 230280 View attachment 230281

Finally got a chance to maiden today. The controls need dialed back. The rudder and elevator are very sensitive. Took off of the water with just throttle. I got too close to the trees and turned too quick and lost control. Going to reduce the throws and add more expo.

 

[FoamyDM]

How important is this bird being a twin?

 

[FoamyDM]

I know this thread is older but I have been intent on building on of these since the start. I finally get started. As hurricane Debbie was rolling in to NC, I thought if I can get this finished, I will have my choice of newly minted "lakes" to fly on and off of

After they were assembly and well glued, I decided to pull from a warn twin 6S model I have, and use the Emax Eco II 2206 1950kv. I am worried about the wait. But I figured to make it really waterproof I need to paint it. So I started with primer to make the color pop.

Then I started to duck it up. As my garage was full, I had to fit the spraying in between the rain spurts.

I had some orange for the duck bill, and used it on the wing tips, and as a nod to the sea duck, on the rudder panel.

I almost managed to get a perfect look. Like this.

But a light rain started before I could rescue it and I have bill top with speckles. But a plane this fun isn't complete without some eyes.

I am waiting for it to fully dry before I apply the flexi-seal coat along the bottom and pontoons.

I know that with a 6S battery this bird has plenty of power, but the AUW with the battery is ~600g before paint. That is much heavier, and I worry if this will fly.

 

[FoamyDM]

AUW after Paint - 675g...
Either this will be FAST, or I will need to extend the wing surface to give it more lift. I can't wait to try it out tomorrow.