RADIO CONTROL: HELICOPTERS
Paul Tradelius 6704 Santiago, Ft. Worth, TX 76133
GAS X-CELL UPDATE
Several issues ago I described the Gas X-Cell in detail. Since then I have talked with others who are flying this fine helicopter and would like to pass on their experiences, techniques and recommendations.
Although the Gas X-Cell flies great out of the box at about 12 pounds, anything we can do to reduce weight will improve overall flying performance. Several people have experimented with the following:
- Convert to electronic ignition. Points and condenser don't add a lot of weight, but a little can be saved by converting. Low-cost, effective electronic ignitions can be found in the lawn & garden section at Kmart or at local lawn mower service centers; they were reported to sell for about $10–$20 and work well. Miniature Aircraft should also be stocking standard high-rpm electronic ignition systems specifically for the Gas X-Cell.
- Remove the pull starter and add a Uni-Ball on top of the clutch shaft so an electric starter can be used. Note: Ted Schoonard mentioned the starter shaft was not designed to take the added torque of an electric starter and there is a possibility the start shaft could come loose from the clutch. To my knowledge this has not yet happened, but it is something to consider before converting.
- Remove the plastic/foam air cleaner for appearance and slight weight savings. Be aware that removing it will void the engine warranty because of the possibility of ingesting dirt.
- Prevent dirt in fuel. Some fliers have had problems with dirt in their fuel even after claiming to filter it. Even a little dirt can clog the fuel filter inside the carburetor. I now use a heavy felt filter (available from lawn mower shops) in my gas can, with the pickup line short enough so the filter does not reach the bottom where dirt settles.
- Remove most or all of the exhaust stack on the muffler. It is heavier than it looks and several ounces can be saved. Miniature Aircraft should be offering a super-quiet (no power loss) muffler and a tuned pipe system producing a substantial power increase.
A final point on the Gas X-Cell: the glitching I was experiencing when using FM vs. PCM disappeared after adding electronic ignition and a metal Bosch resistor plug cover. The cover is available from your local Bosch dealer or CH Electronics, Tel.: (307) 857-6897, for $12.95 plus shipping and handling.
A NEW RADIO
It has taken a while, but I finally convinced the boss (my wife) to let me get a Futaba 9Z synthesized radio. If you had told me a few years ago I would spend this much on one radio, I would have thought you were nuts. But I did it, and it is the best radio I have ever had.
This radio is particularly useful because I have several helicopters using Futaba equipment on different frequencies; now I can fly them all from one transmitter. One minor criticism: changing models, frequency, and modulation (PCM or PPM) requires three individual steps. It would be nicer if selecting a model automatically set the correct frequency and modulation; perhaps that feature will appear in an update.
Another justification for the expense is the ability to have eight completely independent flight conditions for each model—each with its own trims, mixing, and flight parameters. The four standard flight conditions are: normal, idle up 1, idle up 2, and throttle hold, plus four additional user-defined conditions. Each flight condition has its own pitch and throttle curves, trim settings and program mixing. This makes it easy to set up and modify individual flight conditions without affecting others. I have only had the radio a few weeks, so it will take experimentation to become familiar with all features.
One downside is transmitter battery life. The standard transmitter battery gives about an hour of transmitter time, and Futaba does not recommend quick-charging their batteries. That means either short flights or carrying spare batteries. Another option is to send the sealed transmitter battery pack to SR Batteries (Box 287, Bellport, NY 11713) and have them professionally install a set of their 800 mAh batteries. This gives about 50% more flight time per charge and allows quick-charging at the field if needed. These higher-mAh aircraft-grade batteries are also available for airborne power supplies— I almost won't fly without them.
HEAVY HELICOPTERS
From time to time the idea resurfaces that heavy helicopters fly faster than light ones. This seems to be a wishful belief by owners of heavy machines who want a redeeming feature, but it's wrong: heavy helicopters do not fly faster; they fly slower.
A simple way to understand this: if a helicopter's rotor system produces just enough lift to hover, it has no excess lift available. If you increase rotor lift or decrease weight, that excess lift can be used to climb or accelerate into forward flight. Since engine and rotor design limit how much lift can be produced, reducing weight is generally the only practical way to increase available excess lift. Therefore, lighter is better.
If anyone doubts this, challenge them to a short race: leave your light helicopter as it is and, to help them, add more weight to their helicopter since they believe heavy helicopters fly faster. Secure an anvil to their model's skids and start the race.
NEW PRODUCTS
- Solarez: A new all-purpose repair and filler expected to be in hobby shops soon. What makes Solarez unique is that it remains workable until exposed to sunlight, then cures in three to five minutes (even in freezing cold) without a catalyst. It works on cracked canopies, servo trays, fuselages and almost anything except Styrofoam—so you don't have to stop flying for the afternoon; repairs can be completed in about five minutes.
- Astrodata BATgraph with DeBug option: Astrodata (421 SW Blakley Ct., Bend, OR 97702) manufactures the BATgraph, an onboard ESV and signal monitor. The BATgraph has a series of multicolored LEDs that display receiver pack voltage, allowing quick pre- and post-flight voltage checks. The DeBug option lights up all LEDs if any portion of the transmitted signal has been missed by the receiver. This feature works only with PCM radios and helps confirm that the radio continued to receive a clean signal during flight. Any short-duration glitches (not even noticeable during flight) will trigger the display, providing early indication of onboard or transmitted glitching problems.
- Tech Specialties wooden rotor blades: Tech Specialties (218 Vernon Rd., Greenville, PA 16125) manufactures a variety of wooden rotor blades. I tried a set on my Enforcer ZR and was very pleased with the aerobatic and autorotation capabilities. These blades are weighted and match-weighted with lead strips to within one gram of each other. Secure the weight, cover with your choice of material, and they are ready to fly. A hardened trailing edge helps protect against hangar rash.
When finished, blade balance can be checked with Tech Specialties' Rotor Blade Balancer: attach the blades to the balancer and place it on a pair of water glasses. A bubble level shows when they are in balance.
Transcribed from original scans by AI. Minor OCR errors may remain.
