Does the SD7037 Airfoil Like Camber?

[Erik_J]

I am debating purchasing a radio that does full trailing edge camber (4 servo wing) - only if the SD7037 reacts well to it.

I really learned how camber affects flight performance with my DLG (2 servo wing). I was hoping someone who is familiar with the SD7037 could give me some input.

[SoCalGliderFlyr]

7035 is better for TE camber. Also a bit faster foil than the 7037 in "stock" profile. However many who have flown the 7037 use TE camber for launch and tight thermaling with great success.

Which radio are you thinking of? I'm currently breaking in a new (to me) 9CAPS.

[davidjensen]

The 7037 also likes reflex and speed up nicely. I have flown 2 ships with the 7037 and camber and reflex are worth the effort. Both ships have a speed barrier when diving. Ballast can help but the airfoil becomes dragy the faster it goes. Reflex helps but the barrier is still there.

[SoCalGliderFlyr]

Try the 7035. I have Seligs comments about it -- somewhere. Might be able to find them on line. From the late 90's IIRC.

[SilentEric]

I fly a 3M Sapphire with a SD7037 wing. I use a camber setting when I hit thermals and reflex when trying to book to the next thermal (I also have a normal setting). I'm using a Futaba 8U Super and my camber/normal/reflex is fixed on a switch setting and adjustable with a dial (which is not very convienent during flight). A sliding camber adust would be a plus for my setup, but the camber definitely helps in thermals on my Sapphire.

Eric

[Erik_J]

I already own an Enigma 2M (still in the box) so I am 'stuck' with the SD7037. I was considering the Multiplex Evo9. I liked the JR9303 better, but then I would have to buy new receivers for all my planes due to the shift. :(

I currently have a Hitec Eclipse 7, but setting it up for my DLG was a pain. It was funky programimg, but it works. Something about the left wing is an 'aileron' servo and right wing is a 'flap' servo. Mixing ch3, reversing, adding 'crow' - {poof} instant camber on the throttle stick.

My understanding is that full camber on a 4 servo wing is not possible with the Eclipse - controlled from anywhere other than that stupid knob on the top left of the tranny.

If there was a measurable increase in performance due to full camber control with the SD7037, that could convince me to pursue the new radio. I don't think my MiniBlade will benefit from full camber too much - I just like the crow feature for slower landings and the Eclipse does that fine.

[davidjensen]

The measurable increase is longer flights and the ability to fly slower (camber) and faster (reflex). The amount of increase is in the skill of the pilot. I find my self constantly changing the camber setting while flying especially when circling in a thermal when there is wind. My Destiny reacts well to camber on the front side helping me gain altitude for better speed runs.

[Ollie]

http://www.charlesriverrc.org/articles/drela-airfoilshop/markdrela-ag-ht-airfoils.htm
The very best airfoils(AG-40 thru to AG-47 with flex degrees and chord %) made for thermal gliders with flaps and ailerons.

[aeajr]

Interesting discussion. I have not played with camber settings yet. My Futaba 9C can handle it so I guess it is time.

I just put up an Prism T-tail. I believe the Prism has a 7037.

[jgleigh]

Purely personal observations, the 7037 seems to benefit from camber in thermals when heavily loaded, but I've never noticed much difference at light wingloadings.

[jrerickson]

I never really cambered the 7037. It has enough already. One other function that you do want, however, is elevator to camber mixing. When you are in a thermal and you pull up, you get a bit of camber. You can really maximize the climb this way.

JE

[aeajr]

I have this mix with elevator flaps. Never though of using it with camber.

How much do you apply when you refer to camber?

[solo6796]

My Super V has a 7037 airfoil. I have set flap camber and reflex on the flight mode switch (Eclipse7). A little camber is helpful when thermalling a tight thermal in low wind for me. Reflex didn't seem to do very much over the normal cruise position, so I changed it to give me a Launch Flaps position.

I get better results thermalling in wind with a little camber, full span ailerons, and rudder not mixed to ailerons. I like rudder on the left stick only, some of the time. This plane needs to fly a little faster than my Hawk to get the most lift out of the airfoil.

AJ

[MikeyC]

Erik, If you want to fly F3J / TD type models then you'll need to buy a new
computer radio to get the most out of the models. I fly a 3m TD/ F3J model
with the SD7037 section and definetly use a small amount of camber when conditions are light or reflex when it is windy and I want to penetrate upwind etc. Elevator compensation is automatically mixed in to eliminate pitch changes. I use a Multiplex 3010 and imho it is the most flexible radio set available on the market for gliders. Unfortunately it is no longer available but an Evo 9, 12 or Profi 4000 (if funds permit) have even more capability.
Don't necessarily worry about the airfoil section alone - get a set that can maximise whatever model you are flying.

[solo6796]

That's a very good point, Mikey...

AJ

[mhodgson]

I bought my first computer radio not for camber changing in flight but to use ailerons, improve the launch and have crow braking for landing. Only after getting to grips with that did I start playing around with camber changing in flight.
You can always build a new wing with a different section that makes better use of camber changing at a later date (which is what I did).
Personally I love the Quabeck sections. Designed for flaps, will fly heavy or light, fast or slow, handle like a dream and can be easily modified (camber and thickness) for whatever design you want.

[FWFlyer]

I use full trailing-edge camber when circling in thermals on a 7037. It really helps the climb. However; if I have to fly straight it makes the plane pitchy. So, if I lose the core and have to travel even a small distance to center up, I have to turn off all camber. Not a big deal, but a nuisance. Is this normal on camber?

Also, I use a JR 388 radio that is 11 years old now. It has all the programming that I need in a full-house glider. JR was ahead of their time when they designed this one.

[mhodgson]

Here is a theory.

The larger the camber the greater the tailplane area needs to be, all others things being constant.

When you droop camber changing flaps you are increasing the camber. Not a problem when circling and the wing is slow and at high angles of attack. If your tailplane is already close to being on the small side then this increase in camber may not be compensated effectively by the tail as you speed up in level flight giving you that pitching.

I'm sure there is more technologically but it seems logical, which is why I tend to err on using slightly large tails than I might actually need.