Thermic 2.5 - Spoilerons vs Flaperons

[shakysticks]

I just ordered a Thermic 2.5 from Art Hobby and I'm as excited as a little kid before Christmas. I know this has been asked before, and I've read some good build threads on the Art Hobby sailplanes, but I'm looking for input on using spoilerons or flaperons on this ship.

I bought the V-Tail aileron version. I know some people have added separate flaps, but for the sake of simplicity I don't want to do that. Since I'll need separate servos for each aileron anyway I figured I would just use the flaperon function on my radio. The question is, should I configure them as spoilers or as flaps? Also, I'm wondering if this airfoil (HN1033) is suited to using some reflex to allow for better penetration.

[trident58]

Configure the ailerons as spoilerons. I have an Art Hobby Boar, which is basically the same model, only slightly smaller. With the ailerons configured as spoilerons, you can reflex them slightly to increase penetration, but on full deployment, they slow the plane right down and make it rock-stable on landing (washout- limits tip stalls). Just be aware that you lose a lot of aileron effectiveness when the spoilerons are deployed- either mix in some rudder with the ailerons or be quick with your left thumb.
Good Luck!
Jon

[shakysticks]

Thanks, that's good to know.

[mhodgson]

I use this method on a large (4m) glider and it works well. Configured mine to come up the full 90 degrees to act as airbarkes as well as spoilers.

If you set the differential mechanically on the servo, when you apply full spoiler the differential becomes naturally reversed.

With this I get plenty of aileron authority even with the spoilers out.
In fact my 3.2m thermal ship will happily do a full roll (well a sort of barelly, floppy roll) under full crow out because of the same setup on the ailerons.

[Hostage-46]

I'd go with Flaperons. I've experimented with both on my XP-4.

Spoilers will allow you to dump lift quite effectively, however you lose the benefit of improved lift at slower speeds you get with flaps by cambering the airfoil. Flaperons are easier to manage in the landing pattern. Generally from 0 to say 20 degrees flap you've added drag and lift,, stall speed will go down a bit, a good thing in the landing pattern. The more flap you drop, the more you brake. The downside is flaps are more likely to hit the ground and stip servos.

As soon as you raise the spoilers, you're losing lift, stall speed goes up. So at a minimum you'll be landing faster, but less likely to tear up servos.

Hopefully you have enough dihedral because when deployed as spoilerons or flaperons, roll control is effectively gone and it's all rudder.

[Masterpiece]

I have a Thermic with flaps seperate (I know you don't want to go down this route). Flaps are good BUT not necessary IMHO. I love the flaps on mine as it really stops it dead wind and you can place it on a dime. Let me know how it goes with what you wish to use.

Personally I'd use spoilerons. If the ailerons were full span then I'd use flapperons. Spoilerons add washout on tip ailerons and make the plane more stable, whereas flapperons on tip ailerons give washin (not good :eek: ) )

Everyones different on this topic but I like spoilerons on tip ailerons.

Have fun ;) with your Thermic. I LOVE MINE TO BITS. I'm currently modifying mine with a adjustable tow hook, and am cleaning up the flaps with a bit of reflex. There are several ways to build this plane to your liking. Check out

http://www.rcgroups.com/forums/showthread.php?t=315316&highlight=thermic

For good building tips (that's if you haven't already :p )

Cheers
Glen

[shakysticks]

I did read that build thread - there's a lot of good information there.

[doughackett]

Whats allowed for RES contest??
I was planning a Thermik 2.5 Poly with Spoilers for RES "contest"
which leads me to wonder if "only" spoilers can "built in"
or do flaps count? :D

[Hostage-46]

RES= Rudder Elevator Spoiler.

Me thinks you'd need to have them built into the wing, I'm sure the AMA gives specifics

[Ledbetter]

I configure mine to act as either flaperons or spoilerons, depending on which dial I turn.

[emersunn]

I had a Thermic 2.5 with no flaps. I experimented with both flaperons/spoilerons and found spoillerons better for landing. The small ailerons have limited effect in reflex or camber, but it semed to help a little.

[shakysticks]

Well, my Thermic just came today (actually tried to deliver it yesterday, but I wasn't home). I am very impressed - the quality is amazing for a plane that only costs $175. The sheeting on the wings is a work of art - I'm thinking I'll just give it a couple of light coats of Polycrilic to show off the nice wood grain. It will probably be a few weeks before I start on it because of other projects, but I am really excited. If it flies as good as it looks I'm in for a real treat!

[wojtek w]

I am (slowly) working on Castor and I do agree that they are beautiful planes.
My solution is spoilerons, for now. I want to try to keep it as light as possible. I figure that if I find that spoilerons are not enough, I can always cut flaps and go w/ crow (and camber changes) later on. I have used spoilerons on Art Hobby Colibri and they did make quite a difference. I like the idea of reducing tip stall as much as possible. I don't think flaperons will be a great help in this dept.
I am a little afraid of cutting flaps right now, since the aspect ratio is so high I want the wing to remain stiff = that would probably mean adding balsa facing (if you cut further than just ailerons it will be styrofoam only) and probably fiberglass or carbon at 45 deg on top of that > more work and weight (+ 2x metal gear servos).
Good luck!
Wojtek

[shakysticks]

I think I'll go with spoilerons. I'm not too concerned about being able to add camber, since I've heard that these things are great floaters anyway, but I do think spoilers will be good if I get it caught in a boomer.

[Masterpiece]

If it flies as good as it looks I'm in for a real treat!

OH YEAH :D , you are in for a treat ;) . From the first flight I got 3 x 100m overhead circuits from one good firm hand launch. Maybe just have been the day but I was happy as a pig in mud.

Enjoy,
Glen