This summer I built this little gem and have been really pleased so far with its performance. Since I live on a lake, naturally my thoughts turned to making it a float plane. The rounded belly makes me think with a little modification it may be possible. Rounding the nose and adding a step wouldnt be hard and maybe some wingtip floats, but my main question is on a pod.

Having never flown a plane with a pod on top, what are the dynamics of retrofitting a plane? As shown here the engine is mounted with considerable down thrust and a degree or two to the right. How would this translate when the thrust line moves so far up? Currently it is fitted with a 7" prop and an 0.074 Norvel.

Let me have your thoughts. Am I crazy?

I was considering doing the same thing to my shrike. There is alot of good information on that thread that would probably help you out. Just check out the "seashrike" thread.

Gosh, why don't you just put floats on it? Inexpensive, easy and fast. And success is pretty well assured.

Jim

While I'm not an expert on the pod mounted planes, I happen to have three ARFs that incorporate the pod mount. The Seamaster, Seamonster and the Mariner. On the Mariner there is supposed to be a 3 1/2 degree up thrust of the motor, though my kit was absent that until I changed it. As mentioned on the related posts, pod mounted motors tend to want to nose over, i.e.pull the hull forward and down unless you hold a bit of elevator initially and when you reach plaining speed you can relax the elevator and eventually fly off the water. The mariner also had a noticeable left cant, which I found to be odd as for example a tail dragger will loop to the left and to counter it, I give it a slight right rudder on take off.

An up=thrust of the pod helps eliviate the nose-over, but once in the air,will tend to climb. Varying speed will change the plane's pitch on the pod motor and to a lesser degree that is true to motors mounted on thrust line. That is why some trainers like the carl Goldberg Eagle has a down and right thrust motor mount.If you trim for level on lets say 1/2 throttle and then give it full, the plane will climb. The Mariner was very sensitive to speed change where as the Seamaster changes slightly.

There are several good flying "boats" ARFs that you might consider looking at before you make changes to your plane, that may or may not work. I keep seeing this small electric listed on this market place for around $50., and I believe it has around 35" wing span.

Crazy? Not. Intersting revelations have been found by exploring changes. But if you are in love with this model, and things don't work out can you stant maybe loosing it. Sometimes the planning and the actual trip is more fun than arriving. But in this hobby, its the out come that counts. If it dont fly.....just have fun doing it.

If a pod-equipped plane climbs with increased throttle, it has too much upthrust. But with a pod, you need SOME upthrust. The thrustline is higher than either the center of gravity or the center of drag. So, th ethrust make it want to dive. Adding the >Right< amount of upthrust will balance the diving moment with a lifting moment (and engine downwash over the tailplane). When you get it right, it will not want to change trim. Also, with that much upthust, the right side of the prop will be getting a much bigger bite of air, so wedge in generous right thust also. 3 degrees up, 3 degrees right is a starting point.

THAT BEING SAID: JRF's suggestion to mount floats is the right idea. Quick, easy, light, and easy to pop the wheels back on for some dirt-flying. Converting it to a flying boat requires changing everything about a plane but the horizontal stabilizer. This is not the effective way to go float flying.

All good information guys thanks!

I had thought about pontoon style floats but I thought I would explore a floating hull concept for a couple of reasons. First, since the plane is small (1/2A) I wanted to keep both the extra weight as well as frontal profile to a minimum. (I suspect the difference between the addition of a pod and wingtip floats vs. pontoon type floats though would be minimal if done correctly.) Second this plane has no landing gear but rather its designed to skid in on the grass on its belly. A floating hull concept would be a natural extension of this.

Plus its just cool.

Thanks for the info on degrees right and up thrust. That will be a good place to start.

Other thoughts?