View Full Version : Design choices

09-20-2005, 06:47 PM
My first electric after 50 years of RC. A sheet foam called Foamtana designed by Lee Ulinger and sold at darrolcady.com. All the support components recommended by the designer are sold on the web site. Hacker 22 motor, 25 controller and 1320 3 cell pack. Flys really well. What I want to do is put it on floats. Anyone have suggestion on foam float dimensions and location of step. I have seen the eflight on floats go off grass so what I want should be easy. I have the ability to hot wire foam and build carbon fiber gear legs.

Jim Casey
10-02-2005, 05:14 PM
Gosh, there don't seem to be any hard points in it to attach struts.

I'm thinking a single float with a couple of thin struts attached to the profile fuselage. This would automatically send most of the spray away from the prop. It wouldn't need to be more than 1 1/2" wide, or you could start narrower and add layers of depron to the sides until it floats as high as you want. The way I imagine the strut is an H, with CF verticals and foam the same thickness as the fuselage in the middle, glued to the fuse all the way up to the wing. Punch into the float and glue into place with a little dab of Great stuff (expanding polyurethane foam-available from Home Depot). It's strong and light. Skin the bottom of the float with packing tape, just to protect the foam from dings and make it slick. Blue foam is a little heavier than white, but it has a better texture for this.

If you need to, you could attach outriggers to the float instead of using wingtip floats. Cocktail skewers are bamboo: Strong, thin, cheap, available at your favorite grocery store.

Give yourself a lot of incidence and either eliminate the float body aft of the step or give it a lot of upsweep because your takeoffs will be high-alpha. An old-timer float with no step, just a sharp transom at about 50%-60% of wing chord would probably be about right.