Espritmodel.com Telemetry Radio
Reply
Thread Tools
Old Dec 06, 2005, 04:39 PM
Team Cobra!!! Ssssssss!
lmopar69's Avatar
United States, NE, Doniphan
Joined Feb 2005
7,853 Posts
Short Tail or Long Tail? Whats the difference?

I know ALOT of you are very smart about this stuff, so here goes.
I am putting together another plane from my crazy ideas and was wondering about this:

First off, the wing span is 6.5 feet, and the elevator is 20 inches wide.

How will it "react" if I make the tail really close to the wing... like 20 inches or so, vs if it is farther back, like 48 inches, or even farther?

In other words, how does a plane handle with a short tail vs a long tail? What are the "Pros and Cons" of each?

Thanks,

Laine

EDIT: There are pics of it on page 2 & 3 now.
lmopar69 is offline Find More Posts by lmopar69
Last edited by lmopar69; Dec 08, 2005 at 08:34 PM.
Reply With Quote
Sign up now
to remove ads between posts
Old Dec 06, 2005, 05:21 PM
Go get them Meg!
lrsudog's Avatar
Cabin 21...
Joined Jan 2001
2,118 Posts
Longer tail moment tends (everything else being equal) to make a plane maneuver more smoothly for a given control input. They can also get away with smaller flying surfaces usually.

Of course, the opposite tends to be true as well; shorter coupled aircraft tend to be more maneuverable, but may require larger tail surfaces.
lrsudog is offline Find More Posts by lrsudog
Reply With Quote
Old Dec 06, 2005, 05:24 PM
Frequent Flyer
wattsup_kz's Avatar
Kalamazoo, MI USA
Joined Aug 2003
2,892 Posts
The tail length greatly affects the CG as well.
wattsup_kz is offline Find More Posts by wattsup_kz
Reply With Quote
Old Dec 06, 2005, 05:36 PM
Team Cobra!!! Ssssssss!
lmopar69's Avatar
United States, NE, Doniphan
Joined Feb 2005
7,853 Posts
Thank you! I guess that makes pretty good sense. Kind of like a "lever" type idea. Duh! Shoulda thought of that.

So, what would you do, go short or long?

Either one might be fun. hmmmmmm, decisions...
lmopar69 is offline Find More Posts by lmopar69
Reply With Quote
Old Dec 06, 2005, 06:38 PM
Fly it like you stole it..
Tram's Avatar
Florence, Al
Joined Oct 2000
29,298 Posts
The longer it is, the more stability you will have.. but several have already said that.
Tram is offline Find More Posts by Tram
Reply With Quote
Old Dec 06, 2005, 06:42 PM
Suspended Account
Silent's Avatar
New York City
Joined May 2005
698 Posts
I like more manuevarability.
Silent is offline Find More Posts by Silent
Reply With Quote
Old Dec 06, 2005, 06:56 PM
Team Cobra!!! Ssssssss!
lmopar69's Avatar
United States, NE, Doniphan
Joined Feb 2005
7,853 Posts
I think Im with you Silent. I will make the tail short and big and see how I like that.
lmopar69 is offline Find More Posts by lmopar69
Reply With Quote
Old Dec 06, 2005, 07:05 PM
Fly it like you stole it..
Tram's Avatar
Florence, Al
Joined Oct 2000
29,298 Posts
78" span with a 20" elevator.. Hmmmmm...

Is this thing going to be electric?
Tram is offline Find More Posts by Tram
Reply With Quote
Old Dec 06, 2005, 07:17 PM
Team Cobra!!! Ssssssss!
lmopar69's Avatar
United States, NE, Doniphan
Joined Feb 2005
7,853 Posts
Yup, right now Im thinking twin motors. S400 direct drives maybe? 2 outrunners? hmm, I dont know, might try both. Dont really know what will work, but I will find out.

This will be the second life for this wing. I chucked the rest of the last plane I had it on. Didnt really like the way it flew. Guess I will see if I like the way this one flies, or, maybe, IF it flies period.
lmopar69 is offline Find More Posts by lmopar69
Reply With Quote
Old Dec 06, 2005, 07:38 PM
Naturally altered
Joined Feb 2005
2,519 Posts
Quote:
Originally Posted by lmopar69
So, what would you do, go short or long?
You'll notice that most 3d planes, those that loop on themselves have short tails. Large pattern planes on the opposite side of things, designed for precise loops that take all the sky, have very long tails, fuselage on them most often longer than the wingspan. That should give you a clue.


Now besides this... simply design the plane to make it look good to your liking.
Cubber is offline Find More Posts by Cubber
Reply With Quote
Old Dec 06, 2005, 07:49 PM
Team Cobra!!! Ssssssss!
lmopar69's Avatar
United States, NE, Doniphan
Joined Feb 2005
7,853 Posts
Quote:
Originally Posted by Cubber
Now besides this... simply design the plane to make it look good to your liking.

LOL, not sure it will look good or not, but it will be rather different I suppose. Im using the wing from the plane in this video... (but putting much larger ailerons on it) http://www.rcgroups.com/forums/showthread.php?t=441643

with two carbon fiber booms (not decided on length yet) going back to a 24" x 6" tail (3" of it elevator) with zagi-like winglets on the sides of the tail.

might be a little "goofy" looking, but hey, maybe it will fly good. Maybe it wont.

I will probably have the booms run forward of the wing also and mount twin motors on the front of them.

Why? Why not! I gotta be me.
lmopar69 is offline Find More Posts by lmopar69
Reply With Quote
Old Dec 06, 2005, 07:53 PM
Team Cobra!!! Ssssssss!
lmopar69's Avatar
United States, NE, Doniphan
Joined Feb 2005
7,853 Posts
Ooooh, I wish I had a couple BIG EDFs layin around... THAT would be cool!
lmopar69 is offline Find More Posts by lmopar69
Reply With Quote
Old Dec 06, 2005, 08:08 PM
Team Cobra!!! Ssssssss!
lmopar69's Avatar
United States, NE, Doniphan
Joined Feb 2005
7,853 Posts
Ok, while Im at it, I have 2 direct drive speed 400 motors that came with a couple Great Planes Slingers i used to have. First off, can I run them as "tractors" or do they have to be run as "pushers"? If they can be run as tractors, any one care to help me guess what props to run? I dont think I have any props except some 5x5 pushers, and I dont think those will work.

Dang, I was hopin to have this done and fly it in the AM sometime.
lmopar69 is offline Find More Posts by lmopar69
Reply With Quote
Old Dec 06, 2005, 08:13 PM
Balsa is for doll houses
Skrogg's Avatar
Texas, San Antonio
Joined Aug 2004
1,647 Posts
Tail is tail
Sorry Mopar i had too...
And whenever I have a set flyn time it rains or the winds are over 1000mph (thats 11mph to us stick pilots)
Skrogg is offline Find More Posts by Skrogg
RCG Plus Member
Latest blog entry: Babymetal!
Reply With Quote
Old Dec 06, 2005, 08:15 PM
Frequent Flyer
wattsup_kz's Avatar
Kalamazoo, MI USA
Joined Aug 2003
2,892 Posts
If they are 6v motors, and you are running them on 2 cell lipo or 6 to 7 cell nimh, a 6X3 prop works well. That's how my Terry is set up. 1 motor and 16oz AUW.

Brian
wattsup_kz is offline Find More Posts by wattsup_kz
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
J plug or S plug, whats the difference? Fiasco Parkflyers 5 Jun 05, 2005 11:12 AM
Corona short tail boom, or long tail boom? Greybird Electric Heli Talk 1 Feb 08, 2005 01:59 PM
Hornet long tail boom kit!! 50feet Aircraft - Electric - Airplanes (FS/W) 1 Sep 11, 2003 10:39 AM
Whats the difference? 72mhz or 75mhz thazy2 Radios 10 Mar 21, 2003 09:33 PM
Mega/Phasor or Kontronic/Hacker Whats the difference? Phoenix-IT Electric Heli Talk 6 Feb 02, 2002 10:54 PM