RADIO CONTROL PYLON RACING
Duane Gall, 1267 S. Beeler Ct., Denver CO 80231; E-mail: stinger4@earthlink.net
ASSEMBLING THE PREDATOR
I would write “building the Predator,” but building is not really necessary with this Almost Ready-to-Fly (ARF) Quickie 500 (Q-500) racer from LanierRC. It comes already built and covered, so all that remains are a few steps of final assembly.
This column will not be a “product review” in the usual sense. My goal in featuring the Predator here is to emphasize several points that have always been true about entry-level Radio Control (RC) Pylon Racing but that outsiders somehow find difficult to accept.
- A good racing model does not have to be expensive.
- A good racing model does not have to be high-tech.
- A good racing model does not have to go outrageously fast.
- You can have a sweet-flying, low-maintenance, everyday sport model that also qualifies for racing competition in case you get the itch to compete later. There is no need to choose between “jumping in with both feet” and not getting involved with racing-type aircraft at all.
Regarding point 1, the Predator sells for approximately $130. That’s right in the ballpark with other ARF sport airplanes of this size. An accompanying photo shows the components as they came out of the box—with the exception of my custom Magic Marker paint scheme on the wing. I suppose that voids the warranty, but you can tell what I have in mind for this model.
The market niche for an aircraft of this type has existed for some time, but it went unfilled until recently. Ready-to-Fly RC Pylon models up until now have been geared toward the high end of the competition spectrum, consisting of all-molded, mirror-finished fiberglass and carbon-fiber aircraft with price tags ranging between $300 and $450. It’s hard to justify that sort of expense to a newcomer. It’s also hard to persuade newcomers that they could build something just as good, for a fraction of the cost, using plain, old balsa and foam—especially considering how many of today’s pilots learned to fly using an ARF trainer and have never even glued two sticks together.
This brings us to point 2: “A good racing model does not have to be high-tech.” The Predator uses conventional materials. It’s easily reparable. The wing has a decent airfoil, and the fuselage is straight and light. These factors together account for 90% of a successful racing design.
As more Predators and similar aircraft make their way into the winner’s circle (which they are already doing), perhaps more newcomers will be encouraged to give racing a try.
Point 3: “A good racing model does not have to go outrageously fast.” The Predator is intended for entry-level racing in the Sport Quickie event (AMA Event 424), using a mild .40 such as the O.S. Max .40 FP or the Thunder Tiger Pro .40. Some local clubs even specify smaller engines, such as .25s. This makes perfect sense. With a wing loading in the sailplane category, a .25-powered Sport Quickie model will groove along nicely at 50–60 mph while you get the feel of flying on the racecourse with other aircraft around you. And of course the thrill of a photo finish is still there.
The question of airspeed brings to mind the story of the two campers who were awakened by the sound of a bear sniffing around outside their tent. One glanced around fearfully as the other calmly slipped on his sneakers and began lacing them up. “What are you doing?” demanded the first camper. “You know you can’t outrun a bear!”
“I don’t have to,” replied the second camper. “I just have to outrun you.”
So if you plan to compete, check your local rules to determine what engines are allowed. More and more clubs are posting their rules on the Internet. As an example, check out the nice site maintained by Carl Dvorak which covers races in northern Illinois and southern Wisconsin at www.q500424.com/. I especially recommend the link to "Pictures." The smiling faces and pretty airplanes are what it's all about.
And last, point 4: "You can have a sweet-flying sport model . . ." The Predator has all the makings of such a model. Whether or not you decide to use the Predator as your starting point, I will conclude this month with a short list of dos and don'ts for assembling your first Q-500 model.
- Do reinforce the front end to prevent the firewall from working loose or breaking off in a hard landing. This is the number-one weak point of all Quickies.
On the Predator, you can epoxy a 2 1/4-inch square piece of 1/8-inch aircraft plywood onto the front of the existing firewall, round the corners, and wrap 4-ounce fiberglass cloth and epoxy around it. Cut the fiberglass cloth on the bias (with fibers aligned at 45° from vertical/horizontal) so it will go around the corner without fighting you.
Be sure to trim away some of the plastic covering on each side so the fiberglass cloth and epoxy will adhere firmly to the balsa sides. If you do this neatly in a triangular shape, you can later claim, "I, a Pee-Wee Herman, meant to do that."
- Don't think you have to use a fancy radio with V-tail mixing to fly a V-tail model such as the Predator. A simpler setup, equally good for racing, is to rig both V-tail surfaces to a single elevator servo using a split pushrod. Then turn the last inch or two of the fuselage into a steerable mini-rudder with a tail wheel or tail skid, and drive that with your rudder servo. All you need for racing is a little right trim on takeoff, and that much area is enough.
- Do range-test your radio before flying, especially if you've done something fancy with the receiver antenna to keep your caller from stepping on it when he or she pushes the airplane on takeoff. One good way to solve this problem without causing others is to route the antenna down the fuselage to the leading edge of the starboard (right-hand) “V” surface, then carefully tape it along the leading edge out to the tip using 3M clear vinyl tape. Any remaining antenna wire can safely dangle from there.
- Don't put a Nelson or Jett .40 on the Predator, or any other engine that generates more than roughly two horsepower. The Predator wing doesn't have a full-depth spar like the pricey thoroughbreds that are sold for expert Q-500 (AMA Event 428) with engines approaching three horsepower. Just as you wouldn't put a Camaro engine in a Honda Civic, you shouldn't overstress this peppy little sport model. But within its class it will serve you well.
- Do double-check the tail incidence before flying. Alignment is the biggest problem with V-tail models—even those like the Predator that come with the fuselage sides precut. Visualize the tail as though it were flattened out into a conventional horizontal stabilizer, and make sure that in that condition it would be at 0° relative to the wing.
To measure the incidence accurately, remove the landing gear and bolt the wing to the fuselage. Set the airplane on a flat workbench, and block up the nose or tail as necessary until the leading edge and trailing edge of the wing are the same height off the bench.
Measure the height of the leading edge and trailing edge of the tail surfaces, making sure that your points of measurement, when viewed from directly above, are exactly the same distance away from the centerline of the fuselage.
Don't make the common mistake of measuring the front and back of the tail cutout in the fuselage sides. The fuselage is tapered! It's wider at the front of the tail than the back! Therefore, if the front and back of the cutout are the same height above your workbench, the tail has a ton of negative incidence (up-elevator) built into it, and you'll need full down-elevator to fly straight and level.
That's all for this month. Be of good cheer; spring is on the way!
MA
Transcribed from original scans by AI. Minor OCR errors may remain.
