DURAPLANE 20 CG??

I'm in the process of resurrecting and old DuraPlane 20 I was giving
and was wondering where the recommended CG would be?
I've found the manual for a 40 online but not for the 20 (yet).
Any help appreciated..
Reply to
David Hopper
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Duracrap planes tend to be heavy. This mandates a more forward CG location. I'd put it between 25% and 28%. Dr.1 Driver "There's a Hun in the sun!"
Reply to
Dr1Driver
Rather than insult his plane, you could have simply helped and be done with it. How does a model being overweight correlate to where it's CG should be, anyway? If I were to add a useless 8 oz. chunk of lead to a plane just for kicks, why would I want to make it more noseheavy afterwards? Anyway, measure your average chord (including the ailerons) and set your cg for 25% of that, and then move it back a tidge from there after flying it. I like 27% usually myself. The problem with some Duraplanes, mostly with the Trainer 40 and the Aerobat, is that they were designed with too little of wing area, and the resulting heavier wingloading gave them this "pig" reputation. It's unfortunate, because the materials are not at fault at all, it was the design. You should pay a visit to
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It takes the Duraplane idea to all new levels.
Reply to
Frank Costa
Excuse me, I DID help him. I told him where I thought the CG should be.
Well pardon the hell outta me. I believe I suggested 25-28%. How did you help him any more?
Given equal wing areas, a heavier model has a higher wing loading. Therefore, it also has a higher stall speed. A more forward CG will make the plane more stable at low speed. THAT'S how a model being overweight correlates to where its CG should be.
I've seen a spad. It's a disposable airplane.
Somebody sure needs to.
Oh, and I'm not entitled to my opinion??? I didn't insult his plane. I simply said they tend to be heavy.
Dr.1 Driver "There's a Hun in the sun!"
Reply to
Dr1Driver
Thanks, guys.. I have a starting point now.
It was a freebie, so all I have invested in it is a radio and that can always be moved to something else...
Reply to
David Hopper
You're so far out there I won't even bother, sir.
Reply to
Frank
Good luck with it David. Remember, it's all about having fun! BTW, there's a coupld of good cg calculators online. You merely plug in a few numbers, and the rest is done for you. One is located at:
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Reply to
Frank Costa
I have flown many planes with very light wingloadings to very heavy wingloadings, and my experience has been that in any case a noseheavy plane, one whose cg is placed further forward than 25%, is sluggish and doesn't flare well.
Reply to
Frank Costa
IF you are able to read, reread my suggestions. My recommended CG range was 25% - 28%. I NEVER said use a CG more forward than 25%. Dr.1 Driver "There's a Hun in the sun!"
Reply to
Dr1Driver
25% is not a "more forward location" however. It is the standard recommended starting point for most any typical plane regardless. I've also never had a stability or snapping issues setting up a heavily wingloaded plane to 27% as well. Now I request that you please keep responses on the NG only, and try to restrain yourself from adding to the spam that already overloads my inbox. Thanks Dr!
Reply to
Frank Costa
| Good luck with it David. Remember, it's all about having fun! BTW, there's a | coupld of good cg calculators online. You merely plug in a few numbers, and | the rest is done for you. One is located at: | |
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Of course, for a plane with a completely rectangular wing like the Duraplane, you don't need any sort of calculator. Just put the CoG 25-30% of the way back from the front of the wing. You don't even need to carefully measure it -- eyeballing it's usually good enough, though using a ruler isn't a bad idea. If it's a plane you've never flown before, put it 25% forward, then fly and start thinking about moving it back, depending on how it flies. The further forward the more stable the plane becomes, but the more elevator throw you need to keep the nose up, and the less aerobatic the plane becomes. If it's too far forward, you won't even be able to get the nose up. As the CoG goes back, the plane becomes more nimble and more efficient, but also becomes more unstable, and at some point it'll become unflyable, going into uncorrectable spins at the slightest provocation.
This 25-30% rule of thumb applies to any rectangular wing. If your wing is swept or otherwise non-rectangular, you can use the calculator, though a little experience will let you eyeball most of those too.
It's only when you start dealing with precision pattern flying, or flying wings that you need to be *really* precise about where the CoG is. The longer the distance between the wing and the tail, the less critical exact placement is. (Flying wings don't have a tail, which is why it's so critical.)
Reply to
Doug McLaren
You're an idiot...I did not say "25% was a more forward location". I said a "more forward location than 25%." There's a BIG difference in the two, Frankie. When you learn to read, you'll know the difference.
The way you misquote and interpret to your own satisfaction makes me think you're a reporter.
BTW, I thought you filtered me... Dr.1 Driver "There's a Hun in the sun!"
Reply to
Dr1Driver
Anyone got another hair we can split?
Reply to
Six_O'Clock_High
You must be an Welles fan. A true artist of the language of DoubleSpeak.
Reply to
Frank Costa
The wing that came with mine was pretty sad (and not the original), so I ordered one from Tower Hobbies. The manual that came with the wing is the one for the entire plane, so if you need a copy, let me know.
The last page talks about adding optional ailerons..
Reply to
David Hopper
Wwow, that's a real mature way to handle things!!!!
-- Viper Pilo
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Reply to
Viper Pilot
Reply to
Viper Pilot
If you will show me where I have misquoted or misinterpreted, I will be glad to clarify MY statements.
Dr.1 Driver "There's a Hun in the sun!"
Reply to
Dr1Driver

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