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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crash_out
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Post by crash_out »

I still like the idea of going to a prop like a 10x7 and slowing the revs down. Something around 7800 would give the same pitch speed and almost 10 more ounces of thrust. That would help the less aerodynamic planes get up to speed. I don't understand everyones fascination with turning a smaller prop faster. But I don't have much say-whatever rules you guys come up with I'll have to go by.
Alex Treneff
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Post by Alex Treneff »

I want to see the planes slower. From my perspective, there's no reason a 28 oz, 36" plane needs to be going upwards of 50 mph.
crash_out
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Post by crash_out »

Good point. Then using a 10x6 at about 8000rpm would give the same thrust, and drop the speed down some.
Alex Treneff
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Post by Alex Treneff »

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by crash_out</i>
<br />Good point. Then using a 10x6 at about 8000rpm would give the same thrust, and drop the speed down some.
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Nick,

Tomorrow if I have a chance I'll put a 10x6 on my Wildcat and see if that's a viable option on a .15. 8,000 RPM is pretty slow, but that's what I thought about 9,000 until I tried it.

BTW - the club meeting is tonight, don't forget! [:)]
adamdb
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Post by adamdb »

For that matter, why so much pitch on the props? What about a 10x4 at 9000 RPM or so. Everyone seems to be fixated on a ?x6 prop. Would probably provide significant additional thrust and a slower speed and be usable on the motors everyone already has.

I agree that slowing the planes down a little would be a good thing. Even more realistic than it is now.
Adam
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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 adamdb</i>
<br />For that matter, why so much pitch on the props? What about a 10x4 at 9000 RPM or so. Everyone seems to be fixated on a ?x6 prop. Would probably provide significant additional thrust and a slower speed and be usable on the motors everyone already has.

I agree that slowing the planes down a little would be a good thing. Even more realistic than it is now.
Adam

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Try it out and report how it works "at altitude", please
Rabbit Leader
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Post by Rabbit Leader »

Most of these planes are barely hitting 50 in level flight, my Macchi was radared at 48 straight and level..at the 9000 rpm limit they are about as fast as the slower SSC birds, although with no rpm limit enforced they can be almost as fast. We've been flying these planes for the better part of a year now, most people seem to like their performance, some think they are too slow, some want them even slower. I personally like them right where they are at, however, if anybody wants to experiment, please do so, but I would like to see some data, such as rpm, amps drawn, motor type, battery type and C-rating, and esc rating. Remember, 28 ounces is a MINIMUM weight, after you've flown your plane at 28 ounces, ballast it up an ounce or so and then try it again, and then post your data. Also, if you have the chance to fly a plane with whatever prop/motor/combo you want to try, fly that plane against/with a 3696 bird to "spec", and get some comparitive data..

Thanks!
Rabbit Leader
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Post by Rabbit Leader »

Oh Alex? If you want to run a 10-6 on a 15 I have one word for you...DIESEL..have fun[:)]
crash_out
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Post by crash_out »

As far as a glow engine spinning a 9x6 or 10x6 prop at about 9K, I'm surprised no one has tried a .30 4 stroke. It ought to be happy spinning a prop that size at that speed all day. Not to mention how cool it would sound....chug-chug-chug.....

I intend to do some testing as soon as I get an operational airframe. Even though my Feathercut is here and I've down a couple of wings on it, I'm in the middle of a move and won't be able to really dig in for a week or so.

I'm not dead set on using any particular combination. I've looked, and am finding an outrunner system capable of spinning a 9x6 at 9000rpms is significantly more expensive than systems turning slightly larger props closer to 7000. Every inexpensive(sub$75)system I've found is out of stock, and has been for a while.

Another problem is who to fly with. This is the same problem I have in any kind of competition. No one living within a reasonable distance of me has either planes or interest to compete. I am basically one of only 3 dedicated e flyers in a very large radius, and probably the only one interested in combat.
Lee Liddle
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Post by Lee Liddle »

Motor $30, esc $15 battery $20. That`s what my system costs Nick. $65. Does a 9/6 at 9k for 16 amps. All of the info is in the thread dedicated to power systems.
crash_out
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Post by crash_out »

Apparently Himodel is closed until Feb 18th for the Chinese new year....lol
Alex Treneff
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Post by Alex Treneff »

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by crash_out</i>
<br />Apparently Himodel is closed until Feb 18th for the Chinese new year....lol
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That's quite a lengthy holiday closure!
Alex Treneff
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Post by Alex Treneff »

Although it is a cool day (52F), an LA-15 turns an APC 10x6 at 7700 RPM. The airplane had way more thrust than necessary - it wanted to lift right out of my hands.

Perhaps 10x6 at 7,000 would be something to test. I'll try it next time out at the field.

Another option would be to go down to .10-size power, such as a 7x4 at a moderate RPM. A 10" prop is going to do some damage in a mid-air.
Lee Liddle
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Post by Lee Liddle »

Alex, Adam and Crash-Out[?]. The main reason that I like the speed where it is, is because it allows the planes to be flown in wind conditions up to about 20mph and still be fun to fly. This is not suppose to be a park flyer type event. We tried that several years ago and it didn`t catch on.

This will hopefully turn into a legitimate scale class where inexpensive electric systems can easily compete with each other and perhaps glows.

If you slow planes down to 30mph or so (4 pitch at 7k is less than 30mph), then you can forget flying in any wind over about 10mph. It will be hard to get a contest day and 10mph winds to happen at the same time.

Do all of the testing that you like, but until you`ve built and flown a plane similar to this in combat and in the wind, you won`t have a clear idea of what it will be like.
Alex Treneff
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Post by Alex Treneff »

Lee, on a 7x4 I was thinking a lot more than 7k. This was always a great combination on our 27 ounce "Attack Bats" that we flew combat with before the RCCA or SSC came along.


(Image won't display, so here's a link) The one in the photo dates back to the 1980's.
http://www.wtrcf.com/swap%20shop%20phot ... 40x480.jpg
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