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Building Tips and technical articles. => Building techniques => Topic started by: Matt Piatkowski on September 14, 2016, 05:22:48 PM
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Hello,
I am building a 400 sq. in wings trainer that will serve as my primary plane to finish learning the pattern.
I am flying the entire pattern already but it is quite crude and I am trying to refine it.
I know that the plane with flaps has better corners but my goal is not to compete but practice to make the regular maneuvers repeatedly.
Should I better install the flaps or fly without flaps and save some weight?
Thanks,
Matt
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IMHO you should go without flaps for this plane. Go with flaps on your next one (and build a bigger plane if you can).
But, it's not a huge deal -- with flaps you'll be struggling more with trim issues, but the plane will fly prettier. So to some extent it's six of one vs. half a dozen of the other.
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I agree. Flaps are a waste on a plane that small. Until you get a lot bigger it won't be competitive with or without flaps.
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IMHO you should go without flaps for this plane. Go with flaps on your next one (and build a bigger plane if you can).
But, it's not a huge deal -- with flaps you'll be struggling more with trim issues, but the plane will fly prettier. So to some extent it's six of one vs. half a dozen of the other.
And flaps are more to fix when you bust it. I've learned that the pin hinges love to shear off in a wreck. The the great thing about flapless profile trainers, they're simple, easy to trim and quick to repair.
Rusty
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Hello,
I am building a 400 sq. in wings trainer that will serve as my primary plane to finish learning the pattern.
I am flying the entire pattern already but it is quite crude and I am trying to refine it.
I know that the plane with flaps has better corners but my goal is not to compete but practice to make the regular maneuvers repeatedly.
Should I better install the flaps or fly without flaps and save some weight?
Thanks,
Matt
Elevator-only airplanes can turn far more than tight enough for any practical purpose. If you read any of my 20FP or 25LA posts, you have my recommendation on how to proceed, and the 400 square inch Skyray 35 or similar, with a 20LA or similar, is the way to go. Sounds like you are in the right ballpark to me. I would also strongly recommend building them in bulk, maybe 3 of them, all set up and ready to go. Go out and fly until you get tired, or run out of airplanes. If you crash the first one, don't go home, just pick another one off the stack, hook it up and keep going.
Brett
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I agree. Flaps are a waste on a plane that small. Until you get a lot bigger it won't be competitive with or without flaps.
Paul,
Apparently you've never seen Brett fly his "flapless" Skyray...... Well, I have and I'll tell you it is VERY competitive!
I know it wouldn't be competitive with ME flying it but then neither would Dave's Thundergazer! LOL!
Just saying..........Jerry
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Apparently you've never seen Brett fly his "flapless" Skyray...... Well, I have and I'll tell you it is VERY competitive!
No, Paul hasn't see it fly. But there are a lot of people with the same impression, mostly based on how they used to fly when all you had was a Fox/McCoy 29 or 35 to fly it with. Put a McCoy 35 on the Skyray, and it isn't very competitive, and is very difficult to get through a complete pattern*. The reason that they needed flaps back when Bob Palmer first tried it was because engines were feeble and they ran 6" pitch props. My dad, who sort of knew something about this at one point in the 60's, looked at the Skyray and assumed it couldn't do square loops.
With a proper engine like a 20FP, it turns much better and the performance is just fine. I think my high score with the Skyray is up around 560 points. I guarantee that, properly setup and trimmed with a modern small engine, these airplanes are certainly capable of winning any contest through a local Advanced class.
But note that Matt said he wasn't geared towards competing, just learning to fly better. In that, something simple like a Flite Streak or Skyray is probably better than a more complex airplane, because the biggest issues are crash repairs, and trim. Crash repairs are obvious - if you are learning, you are going to crash, and if you are afraid of the consequences, you aren't going to be willing to push yourself enough to learn. Simple airplanes are also simple to repair and replace.
But trim is the real reason to not use flaps. Read Ted's "Medic" article, one of the goals was to come up with a good airplane without flaps, because they are a snap to trim. Get the wings level, get the CG right, add tipweight until it hinges, then back off one step, and you are more-or-less done. Trim and engine setup will make far more difference than all the supposed "design innovations" that people love to talk about.
Brett
*although I actually beat David in a local contest once with the Skyray (original kit version complete with spruce spars, plywood ribs, and 6-7 unnecessary ounces) and a Fox 35. Dave was flying his full-fuse Imitation (which had finished 6th at the Team Trials) and a brand-new piped PA40. The only problem was that I was second and David was third - behind Bill Howe with his ST46/Macchi 202 based on a SIG Magnum kit. We usually don't go around bragging about first and second losers....
This was with an L&J Fox 35, running - wait for it - a Rev-Up 9-4, making a sound no Fox should ever make, with JBK 15/29 fuel. That was to overcome the burps that happened incessantly with a Top Flite 10-6, in those days long before Frank Williams finally diagnosed it and came up with the bypass stuffer modification. Two flights with the 9-4 shook the airplane apart and it had to be stripped, reglued everywhere, and then recovered, AND, the rod ate through anodized surface of the stuffer backplate and about halfway through the metal, in a mere two runs.
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I have flown, seen and built plenty of smaller flapless planes that fly quite well.
But I also see that people who want to win fly very large models with flaps.