I've read here and there that thermal pilots can adjust the camber of their wings using flaps to create better lift. So, Couldnt I use a minimal amount of flaperons to achieve the same effect? Why or why not?

It is possible to improve a wings lift by adjusting the camber with flaps but setting it up to do that is going to depend on your radio system. If your radio only has a flaps up/down switch then it's not going to work as well as it would if it had a "Dial" control that allows you to use only partial throws and hold them in that position.

This doesn't only work for thermal planes. Years ago I modified a 2 meter poly bird that I flew on a slope to include flaps. I could face the plane away from the slope at the crest of the lifting "wave". drop the flaps and actually hover in place with no control imputs from me at all. Turned out to be a handy thing to be able to do when I wanted to take a break and stretch for a minute or two.

My latest modification was to a 99 inch Windfree that I built from a 25 year old kit. I swapped out the thin spruce spar stock for solid carbon and added a sub-spar that ran the full length of the wings. I attached flaperons to the sub-spar and controlled then with Hi-Tec M125MG servos which barely fit into those thin wings. The difference in flying this version versus a stock Windfree is nothing short of amazing. Going from rudder/elevator only to having the additional controls in the wings improved the flight characteristics 110%. It will thermal tighter and can use lighter lift than it could before. Plus it looks pretty cool to me as well.

Another thing to consider is to make it so your flaps can be reflexed upwards a bit. This will give you faster speeds when flying through sink while you're moving from one thermal to another. Reflexing the flaps acts to extend the airfoil. Needless to say the less time you spend in the sinking air the better.

The only silly question is the one you DIDN'T ask.

Jeff

Hey thank you. I shouldnt have said flaperons, I meant using negative spoilerons to act as flaps, can that be done?

Look into crow (Butterfly) Camber changing. Once you put flaps, and ailerons on a glider wing (full span) both are possible.
Your question will lead you to start asking about the full meal deal. I hope someone will add a link to a full explination article. A very basic explination:
Flaps add lift.
Flaps, and ailerons down a small amount. equalls camber change, slower flight, increased lift throughout.
Flaps down hard, ailerons up, equals Crow. Distroys lift, dramatically slows down forward motion. Used for spot landings.
Flaps up, ailerons up, a small amount (2-5%) Reflexed airfoil. less lift, traded off for increase in speed. Good for getting out of sink.
These are the features that a sailplane radio has built into it and easier to access then a lot of complicated mixing. Also known as a 4 servo wing program.
Hope this helps.
-Snuts-

what if I have no flaps?

The best thing to do in reality is try a little. You will answer your own questions this way. It won't KILL anything, I expect that with two trailing edge levels. Or angle of attack, it will mildly simulate split flaps, and slow you down as much as it creates additional lift. If your ailerons are full span, this would better replicate camber changing.
-Snuts-

Reading through the thread I am not sure I understand what control you are trying to use.

I fly all kinds of gliders. My DLG,, a Polecat XP-5, has full span ailerons that I have connected as flapperons. That allows me to control them as ailerons or flaps.

I have 3 presets

Neutrual - normal position
camber - both ailerons/flapperons slightly down - thermal/float position
Landing - Both at about 45 degrees - used typically just before I hand catch.
I could have reflex position, with both slightly up but I find I don't need it.

camber and landing have elevator mixed to maintain attitude.

I could have more positions if I wanted. I also have them on a dial for infinate adjustment but I usually just use that for fine tuning neutrual.

"camber - both ailerons/flapperons slightly down - thermal/float position "

Thats pretty much what I was looking for.

Thank you

As an experiment I set up a basic two meter flat wing glider with full span quite wide flaperons. And yes, using small amounts of flaperon to alter the camber worked very well for both slowing it down for thermalling and slightly reflexing it for speed runs back upwind.

But bad things happened when I tried to use them as actual flaps for slowing down. The adverse yaw effect took over from the proper aileron direction. At one point around 30 degrees deflection there was NO aileron function and as the angle was increased the adverse yaw was so strong that the aileron function was actually slightly reversed. This is why coupling the flaps and ailerons for small angular changes is a good thing but once the flap angle is increased past that point you want the mix to reverse and move the ailerons back up to neutral with increased flap angle.

Also the usual really narrow strip ailerons that are only around 5% chord don't work worth a hoot. The flaperons need to be at least 15'ish% wide and 20'ish% is primo.