Polyhedral and v-tail? Bad idea?

[Mahoo]

I was going to build a simple stick floater with a 50" poly wing and just for something diiferent would like to build a v-tail. In searching the internet for v-tails all the planes I have found are not poly wings. I would think there is a reason for this. Is this V-tail idea a bad one?

If it is a good idea, is there a rule of thumb for sizing the v-tail?

Thanks, Mitch

[Sparky Paul]

I use poly and vee-tail a lot..
http://www.angelfire.com/indie/aerostuff/Multipix/eSpiritx8.jpg
Go here for more info on sizing...
http://www.charlesriverrc.org/articles/design/vtailmsganthology.htm

[Sail 'n Soar]

Sparky,

An interesting looking model. Can yuou provide more info on the wing geometry, e.g., AR, root and tip cord, polyhedral angles, any wash out, etc.?

Gerry

[Sparky Paul]

Sail, that's a House of Balsa 2TEE kit.
A tad modified. :)
The center section is constant chord, 9",29" span;tip chord 7", span 24".
No deliberate washout. :)
Tip panel dihedral 5".
Added spoilers... highly recommended!
The vee is sized per the Charles River stuff.
http://www.charlesriverrc.org/articles/design/vtailmsganthology.htm

[ChrisP]

I'm with Sparky. I LOVE electric powered sailplanes with polyhedral plus V-tail.

I'm currently flying this setup in a Tic Tac II from Kyosho. It has no ailerons, just 2 servos to the tail and mixed at the transmitter.
It flies just as crisply as many a good aileron model. It certainly is no problem at all to pull it quickly round into a thermal when you see the model twitch.

Just keep the linkages as slop free as humanly possible if you're using the V-tail for both elevator and rudder functions.

[Mahoo]

Thanks for the responses. It looks like you can't have too big of v-tail control surfaces from what I've read in the above links. I'm excited to try it on this simple stick plane. One other item, the link mentions v-tail control surface size and the amount of dihedreal are matched to get good control. From the above poly referenced wing, I will also use 5" tip dihedral for my 50" w.s.

Thanks,
Mitch

[Sail 'n Soar]

Originally posted by Sparky Paul
Sail, that's a House of Balsa 2TEE kit.
A tad modified. :)
The center section is constant chord, 9",29" span;tip chord 7", span 24".
No deliberate washout. :)
Tip panel dihedral 5".
Added spoilers... highly recommended!
The vee is sized per the Charles River stuff.
http://www.charlesriverrc.org/articles/design/vtailmsganthology.htm

Thanks for the stats.