RADIO CONTROL SCALE AEROBATICS
Mike Hurley, 11542 Decatur Ct., Westminster CO 80234; E-mail: m.hurley@attbi.com
3-D SECRETS REVEALED:
Fliers who are new to 3-D often come up to me and ask how my airplane is set up. Do I add a lot of weight in the tail? How much throw? Do I use gyros? Some even get mad about the gyro issue, stating that those maneuvers (Torque Rolls, Harriers, etc.) are impossible without gyros! One guy started yelling at me when I told him "all it takes is a lot of practice," saying that he's tried all of the maneuvers and there has to be more to it than that. He claimed that we were holding something back, and he was mad that we were keeping it a secret!
Frank Knoll Jr. often states that he can teach you how to Torque Roll for $100; just go out and buy a $100 worth of fuel and do nothing but practice Torque Rolls!
I've been thinking about it, and actually it sort of stares us right in the face. There is a real reason why some people can learn to do these maneuvers more quickly and easily than others. There is a way for you to learn with less practice and less difficulty. It's not gyros and it's not some secret center of gravity. Some of you may not like it, but it's a fact: it's the size of the airplane.
It's not very popular to tell people they need bigger airplanes, because large models are expensive, and that puts them out of reach for many pilots. But the easiest way to learn to Torque Roll is with a 40% airplane. Going down in size from there adds difficulty, and once you get smaller than, say, roughly a 96-inch wing span, the task becomes daunting. Please don't write to tell me you have a buddy who can Torque Roll his ¼-scale CAP 'cause I know it can be done, but if you want an easier road, there you have it—my secret to learning 3-D.
The problem with that bit of information is that it's really not wise to go out and buy a big airplane without working up to it and gaining experience first. The big models require different control systems—mechanical and electronic. They use large, very powerful engines that can be dangerous to operate (not that the small ones aren't dangerous!). You need to learn to fly them in a different manner so that they don't disassemble in midair, and a slightly different safety etiquette should be demonstrated so that others in the area are safe when you operate a large model.
Inexpensive TOC-size Kits:
Now that you know that 3-D can be easier to learn with a big airplane, you might want to know where to get an affordable Tournament of Champions-size Scale Aerobatics (SA) aircraft. Lanier has long been associated with manufacturing some of the largest aircraft and is keeping up with the times. The company has come out with several affordable SA aircraft that have 115- to 120-inch wingspans and weigh in the neighborhood of 40 pounds. Styles include an Edge 540, a Staudacher S600, and a Sukhoi Su-31.
I've always loved the Goldberg Su-26 and have wanted a Sukhoi for a long time, but I haven't owned a glow-powered airplane in years. So when Lanier introduced its 37% Su-31, I jumped at the chance to buy one.
If you look closely at the full-scale Sukhoi (the moments, the size of the control surfaces, and the total ratio of flying area to stationary area), you'll see that it's designed as a 3-D monster right from the start—no modifications necessary!
Unfortunately I have a bunch of airplanes on the drawing board, so it may be a while before I get to build mine, but I did open up all the boxes and study the kit. Lanier has raised the bar considerably. The wood in this kit is all very nice quality, the laser-cutting is beautiful, and the fiberglass work is very good (although the louvers on the cowl are backward).
The kit builds in a very conventional manner, with foam wings, rudder, and stabilizers, a fiberglass cowl, and balsa and plywood for everything else. There are no cheesy plastic parts. As usual for a production kit, some of the wood parts look as though they could be substituted for something a bit lighter, but Lanier designs these parts to take a little more abuse than they should ever see. So for those of us who like to tinker, there are some weight savings to be had with the Lanier Sukhoi. (Those savings would probably be minor; this airplane is not overdone!)
For my model I decided to cut a new rudder that was closer to scale. For some reason the height of the fin looks very short (my guess is so that it will fit in the box). I also noticed a very interesting selection for the main wing's airfoil—an Eppler 169—and all the big Scale Laniers use a wing that looks to have a slightly higher aspect ratio than scale. I'll have to wait and see how those changes handle in flight.
All in all, it looks to be an excellent kit that is every bit as good as the competition when it comes to the quality of the components and costs approximately 30% less. That's not too bad. I can't wait to get mine flying.
How to Set Up Dual Receivers:
The idea of running dual receivers can be confusing to someone who has never done it, but it's fairly simple and straightforward. The question you should be asking yourself is, Do I really need to run two receivers?
Some people mistakenly think that the purpose for two receivers is failure backup or redundancy. Although a second receiver may indeed act as a fail-safe backup in one or two remote scenarios, I hardly think the extra weight and cost is worth it. In fact, a second receiver can be the source of problems if you use it in too small an airplane where the receivers cannot be adequately separated. Some even argue that a second receiver unnecessarily provides an additional failure point.
If this is true, why do we see some airplanes flying with two receivers? A receiver has a threshold of 3.2 volts. Drop below that mark, and you'll start to see clipping of the output to your entire system. As more high-draw servos such as the high-torque, high-speed examples commonly used in giant SA aircraft are added, the load on the pack, switch, and receiver bus is increased, and eventually the voltage will drop below threshold even with a full charge.
Aircraft that are very large, as are most 40% SA aircraft, use more servos than a single-receiver system can handle, so the quickest and simplest solution is a second receiver, switch, and battery to include the servo load between two systems.
My opinion, and that of some of the experts I consulted on this topic, is that any aircraft with fewer than 10 high-draw servos will be better served with only one receiver. That includes all 3/5 and smaller SA aircraft. Not until you reach the demands of the huge 40% airplanes that have as many as 11 or more servos will you really see a benefit to need for two receivers.
To properly install two receivers you must separate them by four to six inches. The associated antennae must also be kept roughly four to six inches apart to safely avoid radio frequency (RF) generated by the antenna and the receivers. Avoid placing the ignition system, including the battery pack and switch, near the receiver packs and switches. All of those components emit slight levels of RF and can corrupt each other.
Then simply set up your receivers as you would normally, each with its own battery pack and switch harness, and split the servos into two groups of roughly the same load demand (servos that are the same and perform the same tasks). I like to split my airplane into halves with one receiver controlling the right of the airplane, with the other controlling the left, with the servos in the right wing into the one receiver and the other two into the other side.
That's all there is to it, and you're ready to go. MA
Transcribed from original scans by AI. Minor OCR errors may remain.
