Radio Control Scale
Stan Alexander [onawing@mindspring.com]
Honest thoughts about radio safety and usage logic
WOW! It's the first of the year already! Either time is moving faster or I'm getting slower.
Will Rogers said, "The quickest way to double your money is to fold it in half and put it back in your pocket." Watching the evolution of radio systems in the past few years, more than once I've put off spending my hard-earned money on a new system. With all the changes that have come about, especially in the last two years, I wonder where radios are going in their evolution and how much faster it will happen.
I've flown Futaba, JR, and Airtronics radios throughout the years. I have a JR PCM 10X, which must have been one of the originals. It still works well and I've never had a problem with the system. The other radios in my shop are basically the same basic four- to six-channel units for sport flying. I go by the motto: "If it works, don't fix it."
It amazes me to see Scale modelers who have had numerous radio problems and have kept a "bad radio" or receiver. Toss the thing in the trash, and quickly, if it doesn't work. Yes, I know you can have a radio serviced, and I have done so myself. But if there are problems in the programming or persistent, recurring issues, you're much better off to toss the thing rather than risk the new Scale model you put 500–1,000 hours into!
I didn't want to spend the money required on a new 10-channel radio system and had been seriously looking at the JR XP9303. It has many bells and whistles, but it comes with a 600 mAh transmitter battery. What's with that? JR does offer a larger-capacity battery for that radio system and now offers it with a synthesized frequency system. The XP9303 is roughly $600, and that's with no servos — still a heck of a deal.
A few weeks ago I went to the local hobby shop and saw the next generation of radios from JR. The XP7202 has a 20-model memory (more than I'll ever use). The transmitter and receiver are constructed with a synthesized frequency system built in. You simply use the key system on the front of the transmitter to select the frequency you want, press clear, and then turn on the receiver. Press the button on the side and the receiver's LED will light. When the LED light goes out, press the button again and the receiver locks onto the frequency and stays there.
The seven channels are about all I'll need for a single-engine Scale model, and this radio's street price is $329.99 plus tax. To someone as frugal as I am, that seems like a heck of a buy. For 90% of modelers, a radio system with six to seven channels is all you'll ever need. With a seven-channel radio you can have flaps, retracts, split ailerons, or a bomb drop or some other mechanical function. The system also comes with four digital servos, so combined with this deal it seems like one of the best buys I've seen on the market in some time. Since I purchased the radio I've gone back to the hobby shop and ordered two additional synthesized receivers for upcoming projects.
We should look forward to seeing what the engineers at the different radio manufacturers come up with for Scale modelers in the near future. Some of us still have the Scale Unlimited 8 radio systems from the 1980s. I wonder what will be next.
Also included in this column:
- Project Stearman update
- Fokker D.VII documentation
Great Planes Stearman Update
I've finished the Stearman and have the engine broken in and ready for the first flights. I ran 10% fuel through the O.S. .120 FS engine for the first three tanks and then switched to a 20/20 mix from Powermaster fuel.
The pushrod sleeves were already installed in the fuselage, which made it easy to run the pushrods to the correct location at the back of the fuselage. I ran the pushrods through and just pushed them through the MonoKote covering for the exits. I used the hardware that came with the model and mounted it according to the instructions in the detailed booklet. The one issue was that the screws were too short to mount the control horns on the leading edges of the ailerons, rudder, and elevators. After scrounging around in the miscellaneous screw box, I finally found some that would work, even if I had to cut the excess off.
One area where I spent extra time was mounting the main wheels and the tail wheel. I didn't use the wheel collars on the tail wheel; instead I used two metal washers to make a solder joint on the tail-wheel axle. It's really quite simple:
- Clean the tail-wheel axle with fine-grit sandpaper.
- To protect the MonoKote covering, cut a slot in a piece of cardboard or an envelope and tape it around the tail-wheel axle on the fuselage. This shields the covering from any hot solder that might drip.
- Coat the axle with a thin layer of solder flux.
- Use an appropriate washer that fits over the axle and mount it as close to the inside where the wheel fits.
- If you have excess solder left on the axle, grind it off with sandpaper or a grinding wheel.
I also put the tail wheel in the freezer before soldering to limit any melting of the wheel material while using the soldering gun on the outside washer. This seemed to work well; there was no melting.
I added tail struts to improve scale appearance and stiffen the tail surfaces. The full-scale aircraft has struts on the tail surfaces, above and below the stabilizer attached to the vertical fin. This is a simple addition that adds strength with minimal weight.
At the hobby shop I looked at different ways to add the struts and found what I wanted in K&S's metal-tubing display. K&S has multiple sizes of airfoil-shaped aluminum tubing in 36-inch lengths. Figuring that at least one of those might be ruined while making the struts, I purchased two.
Back at the shop I considered how best to attach the struts to balsa inside the rear tail surfaces. Other modelers may have a better way, but here is what I did:
- Crimp one end of the tube with ordinary wire pliers.
- Drill a 1/16-inch pilot hole in the middle of the crimped end and use that hole to mark the MonoKote where the crimped end will attach. Use a punch to mark the model.
- Screw the strut to the tail surfaces, then remove the screws and sparsely coat the inside of each hole with thin ZAP to stiffen the threads.
- At the strut attachment point on the fuselage, gently twist the crimped end with pliers to match the curve of the fuselage.
- Use a Dremel tool with a grinder to round off the sharp edges of the crimped ends so they won't dig into the MonoKote or balsa.
Fokker D.VII Documentation
It would seem that this has been the year of the Fokker D.VII, with Balsa USA's 1/4- and 1/3-scale kits. M.A. "RC Giants" columnist Sal Calvagna built a new 1/4-scale kit and reviewed it in the July issue. The kit is in my workshop now, but I'll wait until a later date to start it. There are so many color schemes, it's hard to find one and settle on it.
This month I have included a photo of some books from the Fokker D.VII series by Albatros Publications of Great Britain. They are available in the U.S. from Hannan's Runway, Box 210, Magalia, CA 95954; Tel.: (530) 873-6421; Web site: www.runway.com.
If you are into World War I aircraft, the Windsock Datafile series of books about many different types and nationalities is an excellent source. The Fokker D.VII series is extremely detailed, with drawings and many black-and-white photos plus color plates of fuselage and wing color patterns. An interesting fact is that Albatros actually built Fokker D.VIIs too because the Fokker factory couldn't produce enough of them.
Fair skies and tailwinds. MA
Transcribed from original scans by AI. Minor OCR errors may remain.
