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Jul 01, 2009, 12:16 PM
just Some Useless Geek
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Slope Soaring: Whitewash cheapie

So, I wanted to do some slope soaring. I figure, if the wind isn't gonna die down then use it to my advantage. This is the same kind of reasoning that leads me to bring a kite to every rocket launch. I'm gonna fly SOMEthing no matter what, y'all. Hence, the Whitewash. Finely crafted from the best $8 glider I could find at the LHS, this plane is my attempt to fly slopes in the wind. Heh.

First off, let me tell anybody else who thinks they can save a few bucks by building from a cheap styrofoam glider as a base: you are wasting your time and effort. (Not your money, but everything else, pal.) There's a reason why those glider feebs put all that time, effort, and money into their gliders. Even stuff like the Easy Star and Upstar and junk like that is far superior to anything you are going to do from scratch unless you apply some real science, and then it isn't a "quick" nor "easy" build. And after all that effort and time you still end up with exposed control rods, delicate structure, and mediocre performance. Blech.

The Whitewash was supposed to be a quick 'n' easy slop job. Surely, thought I, this will be a simple exercise in getting a glider set up to use some R/C control surfaces. What's the Big DealŪ? Well, just getting the thing to stay together long enough to survive testing is a chore and a half, but making it actually work in a stiff breeze is another level altogether!

The wings want to come off at the slightest provocation. No matter how well they are glued to the airframe they will depart with a less-than-perfect touchdown, a heavy up/downdraft, or the drop of any nearby pin. So, the wings required a CF rod slotted into them, and, since they were already attached to the airframe, through it as well. After the CF was added I had to go back and fill the airframe slot with a 3mm slice of Depron. Yummy.

Getting the horizontal stab angle right is not just pure science, it is an art. Guess at the right incidence, sacrifice a chicken, stroke a rabbit's foot, and glue the stab into place. If the plane misbehaves then slice it all off of there and try again. You can forget about using the original glider's stab incidence, because adding the mass and dynamics of an R/C guidance package makes it a different airplane.

The rudder is a joy unto itself. Notice how most of the changes and additions to the Whitewash were done in actual Depron, whereas the last change -- namely, the increased rudder size -- was done in whatever foam happened to get in the way of the knife first? By this time I just wanted the durn thing to work, and I wasn't interested in wasting any more of my expensive Depron or Cellfoam 88 when I had all that Owens-Corning crud lying within easy reach. By the way, I haven't flown this rendition of the plane from a hilltop yet, so I still don't know if it'll work.

So, as a result of all this effort I can tell you to save your time and whatever hair remains on your head. Go to the LHS or your favorite Internet hobby source and get a pre-built glider of some kind. Those folding prop things can be had for 70 or 80 bucks these days. Save yersef some hassle and just buy one. Oy, vay!

12 Jul7 09

Okay, tried to fly this pile of scrap out at the Scenic Overlook at Greene Valley today. Nothing doing. Not enough wind, and it was coming from the north, the only direction from which you can't get any flying done at all. There were a couple of guys from another club with a CF/balsa & covering, folding prop glider. They had no problems, but they were also up high enough to take advantage of the thermals.

The Whitewash simply didn't have sufficient lift in the 4-6 MPH winds to be of any use. So, I am gonna try shaping the wings a little to get some more lift out of the durn thing. If that doesn't work I'll stick a motor on it and call it an airliner. Heh.

31 Jul 09

After reshaping and retaping the wings the Whitewash works a lot better, but still not well enough to go fly with the Big Boys. It still didn't have enough mass to penetrate the wind at about 12-15 MPH. After a tail-breaking crash landing (!) I repaired it and attached a 33 gram chunk of lead. Then it would at least fly reasonably well in a hand launch.

I'll add even more weight and try some discus launch. This thing isn't a DLG, but at least I can get in a little more flight testing before going back down to Woodridge to embarrass myself again. Heh.

Final note

What a pile. After breaking the fuselage in half for about the fourth time I decided to call it quits on this heap. Look for the tail section to be used on the Resuscitator and the wings to be used on something yet to be determined.
Last edited by A Useless Geek; Oct 15, 2009 at 04:46 PM.
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