3696 guide lines for 2007

You got a cool electric WWII combat rig? This is the place to show it off!

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Ed Kettler
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Post by Ed Kettler »

Anybody got any changes, or are we going forward with this until mid-year 2008?
adamdb
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Post by adamdb »

I think it is fine as is. The only thing I might change is prop selection. There are E props that are designed to work well at this RPM, probably much more efficiently than the MAS 9x6. But I do like the idea that everyone uses the same prop, no exceptions.

Airframe size and weight seem very good.

Adam
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Post by crash_out »

The only thing about specifying an E-prop be used is that that will exclude a glow engine. Admittedly, the MAS "Electrc Only" 9x6 is as tough as any glow prop that size I've seen, it theoretically shouldn't be used on a glow engine.

As much as I hate to admit it, I think either the glow prop spec should stay, or it should be specified that the E-9x6 is leagal for electric while the glow 9x6 is legal for glow engines. I plan to test both the E and glow props on electric motors this weekend to see the amp draw and rpm.

Everything else I see in the proposed rules seems a happy compromise. I still like the idea that the plane only has to be 2 inches wide, regardless of scale-I only have access to 2 inch foam where I live, and it is wasteful for me to double it up to a 4 inch fuse only to cut 5/8 inch off each side to reach the scale size for a Mustang. Though I admit the 2 inch wide zero I built looks pretty strange. On that same note, is the scaleness of the wing chord and taper in question, or are we allowing some fudge factor there as long as it isn't grossly overdone?
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Post by Rabbit Leader »

Lee forgot to update the 3696 rules as the original MA 9-6 is long gone, it's been replaced by a thinner bladed prop that doesn't work as well. It spins up faster, but doesn't pull near as hard, and if you dial it down to 9000 rpm, the perfomance drops quite a bit. The next best thing we tested was the APC gas 9-6, theres a thread somewhere that has all the results of the testing that was performed.
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Post by crash_out »

I noticed that-the props I picked up were G/3 props. What about Top Flite wood, Graupner, or Kavan? Guess I could pick some up from HL to see how they work.
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Ed Kettler
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Post by Ed Kettler »

Colonel Hargettski,

Department 3696 of the Directorate of Military Aviation has evaluated your submittal of the Polikarpov I-16 for consideration, and has determined that it cannot meet Directorate specification 2007-3696 Section 2:
<i><font color="red">The plane will be at least 24 inches from the rear edge of the prop to the elevator hinge line and have a body that is at least 4 inches in height and 2 inches in width, measured at a point just in front of the windscreen. </font id="red"> </i>
as the total length of your design is a mere 24.5 inches and the distance from the rear edge of the propeller to the elevator hinge line is only 20.5 inches. Further work in this direction shall be met with serious consequences, including banishment to the Gulag. Consult Scale Factor Analysis 3696 prior to submitting any further designs for consideration


Comrade Commissar Eduard Kettlerov
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Ed Kettler
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Post by Ed Kettler »

After reviewing the drawings for several radial engined planes, we need to re-evaluate the 24" length requirement, as several well used planes, like the Wildcat and the Zero, are slightly under that at 22" and 23", respectively. Depending on the motor and prop adapter used on the Zero, you will either side of legal at 24, but OK if we go to 23" or 22". The Wildcat pushes the limit to 22", which is as about as far as I can see to keep the mainstream planes in the game. Sorry about the Polikarpov, Cash, but dragging the limit down to 20.5" for one relatively low interest plane may open a can of worms for competitve advantage.

Note: I am not saying that the Polikarpovs were not important planes, but given their girth (5+") and stubby noses, few folks will try to build them for 3696.
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Post by crash_out »

The plane will be at least 24 inches from the rear edge of the prop to the elevator hinge line and have a a body that is at least 4 inches in height and 2 inches in width, measured at a point just in front of the windscreen.

OR...the plane must be within + or - 5% of exact scale (proof of scale rests with the pilot). A 5% plane is still required to meet the maximum span and area rules for the wing.

Would that scale +/-5% rule not allow a plane with a smaller prop-to-elevator dimension to be legal? As long as the pliot showed that the plane scaled to 36" wingspan would be that size?
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Post by Rabbit Leader »

That kinda covers it..I had brought that up when we first started messing with these planes, nad Lee had the foresight to include the + - 5 percent addendum. Methinks Colonel Kettlerovsky's worried that the Polikarpov might be a tougher opponent than the Brewster[:D]

Btw, Colonel, I got your e-mail, I couldn't open the file right off the bat, but I have another program that can...ya'll be nice to me this year, or I will build it!! YES I WILL!!! AHHHHHAHAHAHAHA!!!!!

Gonna go put my foil helmet on now..
Cash
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Ed Kettler
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Post by Ed Kettler »

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Rabbit Leader</i>
<br />

Gonna go put my foil helmet on now..
Cash

<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">

Are you going to wear it or sit on it?
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Ed Kettler
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Post by Ed Kettler »

As long as we all agree to that interpretation, I'm fine. We might want to provide a list of the "stubbies" so a CD can easily do his job.
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Post by crash_out »

I agree. It's good that burden of proof of scale rests with the pilot-that way when a little known or odd looking plane shows up the CD will be able to determine it's legality. I think anyone that's going to go through the trouble to model a little known subject wouldn't mind supplying at least a three view and some scale measurements.
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Post by Lee Liddle »

Yes, that`s exactly why the OR part of "guideline" 2 exists. I don`t know what other way it could be interpreted.

Short planes are ok as long as they meet the 5% rule.
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Post by Ed Kettler »

Do we want to say any 9x6 prop for singles, given the change in prop design by MAS? I am also experimenting with 8x6 APC gas props on twins, as well as a variety of 7x6 props.
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Post by Rabbit Leader »

I'm open to it, at least right now.. as long as it's a 9x6 and not spinning any faster than 9000 rpm. I think that a little experimentation might work, even though we have a max RPM limit and some wing area and weight limits, I still think different aircraft will fly better/worse on different props and motors. We won't find out till we try..
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