What has been the weights of HLG's with 2, 3, and 4 servos?

From : Mark Navarre

My Monarch 94 with homemade bagged wing & 2 servos is 8.75 oz, The Wizard with 4 servos is at 12 oz, and I also have a scratch-built on a Climmax fuse with 4 servos that weighs 11.5oz. Recently sold a Mapleleaf 4 that weighed 9 oz w/2 servos. All servos are Cirrus CS21 with 2 screws removed, RX's are Hitec 555 without cases. Batteries are 110 or 120 mAh 4 cell packs, except Wizard with a 150 pack.

If really light, are these bagged, or built up?

All bagged, Mapleleaf and Climmax have sheet balsa tail surfaces. I have never been able to get a built-up plane even close to what I consider light, and still have durability for contest use. (forget about airfoil section accuracy!)

What are the opinions on needing weight to get a high launch versus lightness for sink rate reduction?

The weight has little to do with it, IMHO. My Monarch has a 1.8% camber, 6.5% thick root tapering to 4.5% thick tip, and WAY outlaunches the Mapleleaf at the same weight. Of course the Wizard blows all my other planes away, and I consider it a benchmark design at this time. Can't wait to see how a "Wizard-lite" will do at ~9 oz !!!!

Launch height is more important than sink rate. The Mapleleaf has the best sink rate of any HLG I have flown, but dead air times equal those of the Wizard, because the 'leaf's launch is so weak. The Wizard will cover about twice as much ground in that time, too!

Do these HLG airfoils require a minimum/maximum weight for optimal airflow performance?

ALL my HLG planes now have very thin (~6.5%) wings, and I have found absolutely that lighter is better. I put the Wizard on a diet by re-arranging the radio gear and removing the case and antenna, and balance weight. Saved 3/4 oz and noticed an obvious sink improvement.

What is the general AR for HLGs?

Have not bothered to measure. 6.5 to 7" root chord, and reasonable planform gives good flight performance. The aspect ratio just "happens". I don't believe aspect ratio is a primary design criteria in a span limited class.

If we can start to build 60" planes at 5 oz, then a chord of 4 or 5 inches might give some great launch height. Does anyone make 7 mm thick wing servos yet????

Besides climb and floating, i. e. Logic versus Encore, does one really see an improvement with flaperons/ailerons vs just RE?

I doubt I will build another Polyhedral HLG. (at least not for contests) Launch height gains from a small amount of reflex, combined with a small amount of camber for better sink, mixed in with INSTANT manuverability, PLUS glidepath control, IMHO are worth the extra two servos. What do 2 servos weigh, under 1/2 oz now? This is a no-brainer.

What is the difference between thicker( rounder )LE's versus thinner airfoils with respect to the angle of attack range and the need to stay within a tighter range?

Have not really noticed. I just fly the plane at its "happy" speed and try to find some rising air. By definition, "rounder" LE's usually mean thicker wings. These are rapidly losing their place in the HLG arena due to lack of launch height.

I have noticed that the Wizard seemed to have a wider speed range after it got a little lighter, but that is pretty subjective.

One of the better ways to judge HLG performance is simultaneous side by side flights of two planes. You make a change to one plane and fly again to note the relative net effect. After a few iterations, some big gains are possible.

All this without computer simulations, Re# effects, v-tail theory, or coriolis effect. GO FLY............

Mark Navarre
Borrowed from the RC Soaring Exchange