FREE FLIGHT SPORT
Gene Smith, 1401 N. Husband St., Stillwater OK 74075; E-mail: [email protected]
In the last 10 years a variety of small electric motors have been introduced that are just right for small FF models. HiLine and Kenway offer several motor/battery/propeller combinations that make it easy to get started.
Several years ago I saw a picture of one of the Guillow's 900-series kits that had been converted to electric using the HiLine Micro 4 motor system. I had the 905 kit, which was the Mustang, so I gave it a try. It was a nice flier—at least until it flew into a nearby creek. In retrospect, the Mustang was not the ideal choice. Because of its relatively long nose, the motor's weight required that I place the two-cell battery as far back in the fuselage as it would go.
I recently decided to try another of the Guillow's series 900 kits: the Skyraider. Dave Rees told me that this model would balance with the two 50 mAh batteries just behind the wing. This proved to be true. The Skyraider went 30 feet high and flew roughly 45 seconds on its first flight. I built the model basically per the plans using the kit wood. I did delay gluing in some of the top formers until the motor, switch, charge jack, and battery were installed.
I installed the Micro 4 by cutting a hole the size of the motor in the front former. I pushed the motor far enough forward that the propeller would clear the plastic cowl ring. I also angled it for 3° of downthrust and 3° of right thrust. I used medium cyanoacrylate glue to secure the motor. Take care, because a drop of cyanoacrylate in the wrong place could ruin the motor.
Another modification was to put an extra center strip in the fin and stabilizer so that the elevator and rudder could be made adjustable. Floral wire or the wire from a twist tie makes a good hinge. As it turned out, the elevator needed no adjustment and the fin adjustment was too sensitive. If I were to build another (I have the Trojan and Typhoon kits), I would make a small adjustable rudder tab instead of hinging the entire rudder.
The plans show a large amount of dihedral. This is very important. It looks a little funny but is critical for easy trimming of the model. The kit-supplied tissue has little or no wet strength, so I attached it dry using a glue stick. I then shrank it using a mist of water followed by a heat gun. Wet and shrink both sides of the wing or tail surfaces at the same time to avoid causing warps. I cut out some of the paper lettering and markings and applied them to the model. I used light gray acrylic paint to cover the white plastic cowl and the canopy framing. The final finish was a couple light coats of Krylon Crystal Clear spray.
Flying starts with a preflight check in the shop. My Skyraider balanced at the front top wing spar. This was slightly forward, but it's better to have the CG a little far forward than too far back. I elected to leave it there, and that has worked well for the first flights. Sighting the wings, I found a little wash-in of the right wing (the trailing edge of the wing was lower than the leading edge). The left wing was flat. Electrics are notorious for high initial torque. This would tend to make the model roll left. Left torque coupled with wash-in of the right wing would have been a recipe for disaster. The first flight would have been a quick left roll into the ground. Pulling out my trusty heat gun, I alternated heat between the top and bottom of each wing, twisting a trace of washout into the left wing and 1/16 inch of washout into the right wing. This allowed the left wing to have a bit more lift than the right wing and counteract the motor's torque.
After selecting the proverbial field of tall grass, I put a 30-second charge on the batteries and launched the Skyraider straight into the wind. The model climbed rapidly to approximately 15 feet, and then it made a turn to the left and several left circles as it caught a bit of light lift and headed downwind. Once the battery ran down, the descent was rapid, as one would expect with this model's high wing loading. But that is what I wanted: a neat-looking small-field flyer.
Bob Schlosberg powers his 36-inch-span Cleveland Viking with a HiLine Dual Mini 6 and three 150 mAh batteries. The model weighs 176 grams and uses a 6-inch Peck-Polymers propeller.
Although the Viking is capable of consistent two-minute flights, Bob uses a timed charge to limit the motor run so that flights average a minute and a half. Longer flights would probably lead to the model's loss since it has no dethermalizer (DT). The model flies with a left-left pattern. The cylinder is from a Cox .020 but is for looks only. Bob uses a digital readout charger that is powered by his van's 12-volt system.
You can control the length of your motor's run by using a shorter charging time. This has the disadvantage of providing less than full power at the launch. Another option is to use a motor cutoff. HiLine sells a neat lightweight timer that can be adjusted with a potentiometer. You can fully charge the motor but limit the run time. Call (919) 778-6653 for information.
I received a nice note from Ferrell Papic, who has built quite a few small electric FF models. Because the new Li-Poly batteries power these aircraft for such long periods of time, he has equipped his 16-inch Hawker Sea Hawk with a 3-gram RC unit to reverse the motor as an effective dethermalizer.
I met Lucas Carlson and his dad John at the Society of Antique Modelers Championships last summer. Lucas was having a blast flying his Blue Ridge Special in the 100° heat. He got to visit with many experienced modelers including George Reich, whose Double Feature was flown in a special event at the Champs.
Unfortunately I was unable to get an on-site picture, but John sent me a photo of Lucas that was taken under better weather conditions. The Blue Ridge Special is no longer kitted. Similar good fliers are the Sky Bunny by Peck-Polymers and the Cloud Buster by Guillow's.
Little-Known Jimmie Allen Design
Be the first kid on your block with a Monsoon Clipper; I am told that this is actually one of the Jimmie Allen model series. You can obtain plans from Graham Knight in England. E-mail him for the price and shipping costs at [email protected].
Memories
A friend sent me an E-mail about some model plans that are available on CD. I have more model plans than I could build in another lifetime, but that is beside the point. There are 10 CDs currently available. They contain articles and plans from old model magazines.
The individual CDs include topics such as CL models, engine reviews, and FF models. Of interest to FFers are:
- Volume #9: SAM Antique and Old Time FF Gas (291 models)
- Volume #10: SAM Nostalgia FF Gas (264 models)
- FF Rubber disc (due out this month)
Each CD is $10 postpaid in the US.
I bought the Nostalgia Gas CD. Talk about a trip down memory lane! I had to pry myself away from the computer so I could get back to the shop. This thing is habit-forming. Contact Thomas Wilk at 301 W. Redwing St., Duluth MN 55803, or E-mail [email protected] for a complete listing.
NRG Wins at KOI
Bob Hanford's NRG design for Nostalgia Rubber and Nostalgia Wakefield won both events at December's King Orange meet. See the April FF Sport column for a source for plans.
MA
Transcribed from original scans by AI. Minor OCR errors may remain.
