RCM Floats (oz6558)

About this Plan

RCM Floats. Floats for any aircraft 5 to 7 pounds in weight, and .60size engine. Float length is 37-3/4 inches.

Quote: "RCM Trainer on Floats, by Earl Harting and Ken Hall.

How about a basic float design that could be used with several types of aircraft, is simple to build, sturdy and (most importantly), works well on the water? Such a design should be appropriate to both beginners and experienced modelers who, for any reason, would like to try seaplane flying to further their skills and get into a new thing.

In an attempt to accomplish this end we started with an RCM Trainer (oz5306) by Bridi Hobby Enterprises. This model is a very good, sound, and practical airplane that should lend itself to the novice seaplane flier. Like everything else, some limitations are recognized when attempting to design an 'add-on' feature to an already successful item. The following prob-lems were noted:

1. The float design must be simple and straightforward. Hopefully, it should be as successful in these areas as the aircraft we were planning to use.
2. No exotic building materials.
3. Easy conversion from land to water.
4. Rugged enough to take a beating and live to stay afloat.
5. Handle well on the water.
6. Modifications to the existing aircraft must be easily accomplished, keeping in mind that they may be a retro fit to an already completed model.

Now that the problems have been identified the design can be attempted. Earl had some experience with seaplanes and float design, so he did the original pencil drawings and Ken did
the construction. Once the construction was along to a point that a mating of aircraft to floats was in order we got together. At first blush it looked like we had mounted the airframe on tennis shoes.

Initially we set the floats up at zero angle to the wing. Now we all know that a wing has to have some angle of attack to fly, but just how all of this good scientific stuff translates to these floats (and our airplane) was a complete unknown. The safe bet was the zero-zero set-up. To try to understand this you might visualize a trike geared airplane with an added tail wheel which is just off the ground when the airplane is at rest. When you would attempt to take such a beast off, you might not get enough rotation and, therefore, the necessary angle of attack to lift. Float planes are the same. On take-off there ois a rotation but now, instead of thelanding gear to act as hinge point, it is the steps of the floats. The aft part of the floats must be clear of the water far enouh to allow the necessary rotation. What all of this boils down to is this: zero-zero is a safe starting point..."

Scanning by Don at EAC, cleanup by theshadow.

Supplementary file notes

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