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Old 01-23-2006 | 01:10 PM
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From: Gardner, KS
Default CG Question

I CGed this plane at 430mm like the manual said. I had about 3/4 or a little more fuel in it. The tank is located in the rear of the plane. So as I use fuel the plane will become more nose heavy right? A little nose heavy is better than tail heavy right? Please look at the photo and tell me what you think.

Thanks
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Old 01-23-2006 | 01:40 PM
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Default RE: CG Question

Ordinarily I'd agree with you but I'm unsure about a canard type plane like your Long-EZ. How did the instructions say to balance it? That is the way to do it, and only that way. And unless the instructions said to put fuel in the tank , it should be done dry. READ!! and FOLLOW the instructions.

EDIT: Forgot to mention, Pretty plane. I hope it flies well for you.
Old 01-23-2006 | 01:47 PM
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Default RE: CG Question

Cool plane.

Nose heavy planes fly poorly, tail heavy planes fly once.

I stole that from Gordon Banks of R/C Report fame.
Old 01-23-2006 | 01:59 PM
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Default RE: CG Question

Since the wings are swept back, your fuel tank is probably very close to the CG. Is that right? Do you have the building instructions? If not give us the location of the longitudinal center of the fuel tank relative to the CG. Most planes are balanced with no fuel, because that is the situation during many landings. Is this your first plane? I fly a canard every weekend.
Old 01-23-2006 | 02:12 PM
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Default RE: CG Question

The directions are poor if you even want to call them directions mostly pictures. All it says is 430mm from the leading edge of the canard wing. Its just an illustration no words. I was watching this thread:

http://www.rcuniverse.com/forum/fb.asp?m=3811485

This thread kind of confused me some had fuel some did not. The instructions from the GP CG machine said if the tank was in the rear to put fuel in the tank. Which makes sense . If I CGed it with an empty tank the plane would be tail heavy until I burnt off fuel. I am new but have mostly bought planes used that have already been built.

The fuel tank is in the back of the plane about 6 inches give or take from the CG.

I really like this plane and would hate to plant it.


Thanks
Old 01-23-2006 | 02:28 PM
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From: South West Rocks N.S.W., AUSTRALIA
Default RE: CG Question

Hi SIREX,

There is a formula for calculating the CoG on a canard aircraft. If you don't have faith in the instructions regarding the distance from the leading edge for the CoG I would post in the aerodynamics thread and see if anyone has the formula.

If you don't have any luck please PM me and I will go through my collection of magazines and see if I can find the article on canards[X(]. You should see my filing system for such info (not).

Cheers,

Colin
Old 01-23-2006 | 02:53 PM
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Default RE: CG Question

This appears to be the plane we are talking about:
http://www.avia-richmodel.com/englis...iew.asp?ID=286
Old 01-23-2006 | 03:23 PM
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Default RE: CG Question

Yes that is the plane.
Old 01-23-2006 | 03:25 PM
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Default RE: CG Question

Have you sent PM's to any of the owners in the other thread asking advice?
Old 01-24-2006 | 06:40 AM
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Default RE: CG Question

Sirex,

I cant help with the CG, but I had to post, due to the photo you attached. First, that is a really nice looking plane. Second, I printed the pic and told my wife that I needed a workshop like that. Her response, "I need new kitchen cabinents." She immediately produced a catalog with the design.[X(]

I just wanted to comment on the picture and share my speed bump to a better work space. haha. When you fly that plane, post some pics, I would love to see it in the air.

JJ
Old 01-24-2006 | 07:20 AM
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Default RE: CG Question


ORIGINAL: eloso6297

Sirex,

I cant help with the CG, but I had to post, due to the photo you attached. First, that is a really nice looking plane. Second, I printed the pic and told my wife that I needed a workshop like that. Her response, "I need new kitchen cabinents." She immediately produced a catalog with the design.[X(]

I just wanted to comment on the picture and share my speed bump to a better work space. haha. When you fly that plane, post some pics, I would love to see it in the air.

JJ
Don't forget to post pictures of the new kitchen for us.
Old 01-24-2006 | 12:05 PM
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From: Upplands Vasby, SWEDEN
Default RE: CG Question

Hi!
Most of the time when we speak about C og G we mean "Without fuel in the tank"!
I noticed that your nose wheel leg spring is mounted the wrong way ...coil spring should point to the rear.
Regards!
Jan K
Sweden
Old 01-24-2006 | 12:32 PM
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From: Masontown, PA
Default RE: CG Question

Nice plane! Let us know when you fly it!

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