Radio Control: Giants
By John A. de Vries
4610 Moffat Lane, Colorado Springs, CO 80915
I just finished installing the pushrods in the fuselage of my current Giant. The kit called for two 3/4-inch dowels to connect the servos to the rudder and elevator. The installation will almost assure that the model will be tailheavy. All that birch in the back with only a .90 up front will require a bit of lead bolted to the firewall before the model will be balanced.
Happily, the added weight probably won't adversely affect the model's performance; it has a bunch of wing area and it will fly slowly. Since the dowels were pre-drilled and grooved — making the wire ends simple to install — I went along with the kit designer's method to move the tail, despite the disadvantages of heavy pushrods.
There are several other methods to connect servos to rudders and elevators. Using semi-flexible plastic pushrods would have been a lighter alternative, at an added cost of about eight bucks. It would have taken two 48-inch Golden Rods.
I could have installed the elevator and rudder servos in the tail of the model. Hidden under the stabilizer, the control runs would have been substantially shorter, providing more positive action. It would have required a couple of four-foot servo wire extensions, though. The price penalty would have been almost $25 and I might have had to buy a couple of electronic traps to install in the lines between receiver and servos. All that wire in back might have competed with the RC antenna and resulted in erratic receiver operation.
Probably the lightest solution to shifting the movable surfaces in the back of the fuselage would have been to install pull-pull wire connections. The only certain cost to pull-pull would be the price of the nylon-coated steel wire, the special connectors, and an additional set of control horns: $10 to $12.
However, there was the cost in time and effort required to provide and install intermediate aligning pulley wheels so that the wires would get a straight shot at the control horns. Since the model wasn't designed for pull-pull, there would have been a bit of "horseback engineering" required to develop wire exits that were compatible with the model's structure.
So I took the "coward's way out" and used the kit-furnished birch dowel pushrods, knowing that I would have to bolt some used tire weights to the firewall to get the center of gravity (CG) right. Since we're not concerned with Giant Scale appearance — the model is a semi-trainer — it seemed to be the least expensive way to waggle the rudder and elevators.
I did, however, forego the hard engine pushrod provided with the model. The only way that it would have worked would have been to find a fuel tank with a hole bored through it (which isn't available). The alternative was to install a bellcrank in the line to the throttle, to lead the push around the fuel tank. I solved the tank problem by spending three bucks on a cable installation. A Bowden cable easily bends around the fuel tank and gives positive throttle control.
Moral of the story: before you begin sticking part to part on a Giant Scale model, check plans and draw control runs between the recommended servo locations and the surfaces and other mechanical features necessary to assure positive control. Also build the model and install control runs while things are open and easily adjustable. Don't wait until the model is practically completed before you install the radio — it's an integral part of the early construction effort.
All-American Kit Cutters
The major-league ad cutter-outer is Doug McMillan, whose latest mailing is stunning. The fourteen double-sided pages, jam-packed with advertisements, are culled from a host of magazines. The ads were for hundreds of Giant Scale drawings that are currently available.
Doug, of course, is the owner of All-American Kit Cutters, at 365 Dutch Neck Road, Hightstown, NJ 08520; Tel.: (609) 443-3175. As the company name implies, All-American will make "kits" from any of the available scratch-building RC drawings. Given the catalog Doug furnished, that's one heck of a lot of Giant Scale aircraft.
Doug has quite a library of plans for kits; his outfit has cut many, and if he doesn't have just the model you want, he'll cut the necessary parts if you provide the drawings. Doug and his crew use only the best materials in the more than 150 "kits" they produce each year. The quality work is well worth the cost.
Year-Round Flying (Winter Tips)
There are a bunch of Giant Scale modelers whose ambition it is to qualify for a "Year-Round Flyer Patch." In much of the U.S. that means flying during the cold and snowy months — a very frigid prospect. Before the advent of electric starters, winter flying often meant sticking the head of your engine in the tailpipe of a running car. That's how we did it in Fairbanks, Alaska.
With today's engines and starters — plus a fully charged glowplug battery — winter starting is a lot easier. The same holds true for gas burners. However, there are a few precautions necessary in the colder climates to achieve satisfactory RC flight:
- Cold batteries in the system (receiver, transmitter, and ignition) won't put out as much as they do during the summer months. Thus, you'll get fewer flights per charge than you're used to. The quicker you get your model and radio into the air after you take them from your warm vehicle, the more reliable your batteries will be. If cold-soaked, you'll be lucky to get satisfactory flights.
- Give your engine a while to warm up before attempting a flight. Make sure that all the moving parts are sufficiently heated to continue running. The same holds true as you fly your model: prolonged idling may allow engine parts to cool and the engine to quit. An auxiliary glowplug battery, or additional battery power for ignition engines, may be required to keep the engine operating.
- Plastic fuel lines and tanks are prone to splitting under extremely cold conditions. Check them both before you fly or suffer a fuselage full of fuel and a "starved" engine. The same holds true for non-wooden propellers. Cold tends to make them brittle, which can be a disaster when they break.
- The flexible stranded wires in the servo system tend to dislike getting cold, even as you do. Sometimes the contacts will contract enough to crack their solder joints; you can only imagine what erratic radio behavior will result.
Of course, dress warmly. You might consider getting a "transmitter muff." The muff will keep your hands and fingers warm, allowing the sensitive movements necessary to control your model.
There are some advantages to flying your model in winter:
- The colder, denser air will give you lots of lift and, if you keep it warm, your engine will respond.
- If you live where snow falls, replacing the wheels of your model with pontoons will give you a broad, white, smooth takeoff and landing surface.
In any event, take the precautions noted above and you will qualify for your AMA "Year-Round Flyer Patch" with a minimum of strain and pain. Big is beautiful — regardless of the season.
Transcribed from original scans by AI. Minor OCR errors may remain.
