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        Wet Whirly-bird Saga

#1 OmegaDot May 22, 2004 07:33 PM

Wet Whirly-bird Saga
 
4 Attachment(s)
I read a notice for a float fly about 50 miles from home, so I decided to check it out. Now it just wouldn't be as fun if you didn't bring something to fly, so I band-sawed some floats out of 1 1/2" blue foam (9" long). These were held on to my old carbon fiber trainer gear with strapping tape. Not very fancy, but good enough to justify a seat on the flight line : )

A quick test in the bath tub showed that there was enough bouyancy and a hover in the living room showed that the CD ROM motor had enough umph to lift the extra load (about 70% power required vs 50% w/o floats)

Late in the day the winds calmed down enough to try a flight over the water. I lifted into a hover and tested the wind strength. With the extra weight, and therefore headspeed, control was better than expected. A climb to 30 ft confirmed sufficient power. Off over the water I went with a whole crowd of onlookers. I made several circuits and then transitioned back to a hover 10 ft off shore. Everything looked good, so I gradually went lower and lower. At about 18" up, I could see ripple under the heli, No water spray, so I comitted and set it down. All good so far. Taxiing was kind of cool using the forward cyclic to motor around and TR to steer.

About 5 ft off shore, I attempted to lift off. The first try was "tippy" so I cut power. On try #2, I got the floats almost all the way out of the water, then one broke free while the other one "stuck" (surface tension??). Well the roll to inverted took milliseconds and my heli was turned turtle.

At least it's fresh water I thought : (

The electronics appeared totally dead when I fished it out and stayed that way until I got home. Some compressed air dried out most of the moisture and fortunately, everything came back to life a while later.

Here are some pics:

#2 AtomHeartMother May 22, 2004 07:48 PM

Hehe ! That's cool !
I would think with surface tension as you mentioned, you would want to ramp up the throttle quickly and make the break from the water as fast as possible. I could see where a slow spool up to lift off would "stretch" the water clinging to the floats. Firewall that baby and I bet it will shoot straight up off the water. Granted, maybe a little crooked(still some surface tension) but better to correct for that at 10 feet altitude than to take 'er swimming. You're a braver man than I ! :) Thanks for sharing the pics.

#3 OmegaDot May 23, 2004 10:28 AM

I was thinking that maybe I should have made the float bottoms vee shaped instead of flat?

#4 EddieNewYork May 23, 2004 10:47 AM

Good to hear it came back!

#5 Earthbound May 23, 2004 01:57 PM

A flat-bottom float has maximum surface tension right up to release. A rounded (or better yet V-bottom) shape allows the tension be reduced gradually.

#6 mattijs321 May 23, 2004 02:17 PM

I have flown with floats on my hornet... Taking off never felt different from normal land take offs. Good to hear your heli isn't wrecked!



http://users.pandora.be/mattijs.van....e/DSC01283.JPG


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