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The Beginners Guide To Flying RC Airplanes Second Edition

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#1) 
PostPosted: 02 May 2010 19:42 
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Joined: 02 May 2010 18:01
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Hello everyone. I"m new to this hobby and need some help. I have been trying to fly for about 4 months on good days (not very often) so I do some building for future flying. I have a 55" w/s cessna foamy (crashed a lot) and a 40 tower trainer glow model (not flown) I"m working on a new project I bought off ebay cheap and it has very bad instructions. It is a tail dragger and I dont know where to put the front landing gear in relation to CG on the plane. I"m sure this is very important for good take offs and landings would appreciate any info on this thanks. :roll:


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#2) 
PostPosted: 02 May 2010 20:16 
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Joined: 23 Apr 2010 00:20
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Location: Whitby, Ontario, Canada
Welcome to the forum tjohn.

Im new to this and the forums too. One thing I can say for sure is, you'll want the landing gear on the bottom LOL just kidding.

If you post brand and model specific, someone will be able to help you out. Good bunch of dudes here!

John :roll:

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#3) 
PostPosted: 03 May 2010 03:06 
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Joined: 19 Feb 2010 18:25
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Location: Oregon Ohio
Let us know what you've got.

I'll take a few measurements of my airplanes and we can get you in the ball park.

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#4) 
PostPosted: 03 May 2010 15:12 
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Location: Corydon, Indiana, US
As a general rule of thumb you will want to mount the landing gear directly beneath the CG. Measure the chord length on your wing. (measurement from the front edge to the back edge) Divide that number by three. Now mount the wing and go straight down from that point. That's where you will want the landing gear.

Another option is to place the model on a CG stand, then use the landing gear to balance it. You could move it slightly forward or aft of the CG point to get the proper balance.

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#5) 
PostPosted: 03 May 2010 17:08 
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Location: Oregon Ohio
I don't think I would put the landing gear under the CG on a tail dragger. Putting it close to the CG will make for eaiser takeoff but I think you might have a tendency to break props.

Here are 4 planes. All the langing gear in under or in front of the leading edge.
Hog Bipe
Great Planes Super Sportster
Hot Stuff
Great Planes CAP 21


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File comment: Hot Stuff, downloadable from the internet
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#6) 
PostPosted: 03 May 2010 19:16 
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Joined: 20 Jul 2009 21:15
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Location: Corydon, Indiana, US
Now that I think about it, the landing gear on my tail draggers are all right under the leading edge of the wing. I see your point, if you landed on wheels that were right at the CG it would have more of a tendency to flip onto the nose.

A trusted source has this to say on landing gear mounting: "Mount the landing gear so the axle is about even with the leading edge of the wing when the plane is level. That’s assuming a tail-dragger. If you want to make a trike gear then mount the main gear about about 75% of the chord back from the leading edge."

That's from http://www.airfieldmodels.com/index.html

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#7) 
PostPosted: 04 May 2010 03:02 
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Joined: 02 May 2010 18:01
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that seems right to put the landing gear at the leading edge of the wing other wise it would want to nose over on landings. thanks for the help.


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#8) 
PostPosted: 04 May 2010 03:04 
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Joined: 02 May 2010 18:01
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also thats a very nice bi plane


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