Thread Tools
Sep 04, 2007, 02:42 PM
.: Looking for Thermals :.
Ricardo RW's Avatar
Thread OP

Flap design rule of thumb for sailplanes

Hi there,

Is there a rule of thumb for a flap in a 2M sailplane?

I remember seen 30% of the chord but I'm not very sure about it. I couldn't even find where I read that tip.

I've searched the Lift Zone and RC Universe with negative results.

Could you please give me some advise?

Sign up now
to remove ads between posts
Sep 04, 2007, 05:20 PM
Registered User
It depends on which airfoil and the four functions (landing, thermal, lunching and penetrating into the wind).

For example see:
Sep 04, 2007, 05:54 PM
.: Looking for Thermals :.
Ricardo RW's Avatar
Thread OP
Thank you Ollie,

I'll take a look to those links.

Sep 04, 2007, 09:30 PM
B for Bruce
BMatthews's Avatar
That's way too much for flaps on most airfoils. Usually you're looking at around 18 to 20%.
Sep 05, 2007, 02:55 AM
Registered User
The Quabeck (HQ...) wing sections, for instance, were designed for 22 % flap chord. With common model sailplane geometries flap deflections take care of the necessary trim changes themselves, i.e. there is little change in elevator trim necessary when you deflect the flaps.

Quick Reply

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Rule of thumb for servo torque jolin Sport Planes 4 Apr 09, 2004 12:06 AM
Is there a rule of thumb for AC weight to Ski size. The Other Dave Electric Plane Talk 0 Mar 17, 2003 07:17 PM
Rule of thumb for motor sizing. HankF Sport Planes 14 Oct 09, 2002 03:58 PM
Rule of thumb for brushless # of turns aireze Electric Plane Talk 5 Jul 06, 2002 09:43 AM
Rule of thumb for center of gravity spark363 Modeling Science 4 Jul 05, 2002 03:31 PM