FREE FLIGHT OLD-TIMERS
Bill Baker, 1902 Peter Pan, Norman OK 73072
Covering materials
In the May Model Aviation I said that Airspan was available only direct from the Solarfilm Corporation. That same month, other magazines carried an ad from Charlie's indicating they had both Airspan and Litespan, and I suspect other free-flight suppliers will soon do likewise.
I would use either of these products where tissue would have been the traditional choice, and gladly escape the frequent punctures, fading, and warping we have come to love so well. But for strength I will go to Polyspan on any project where silk would have been the traditional choice — cheaper, stronger, and likely lighter, considering the amount of dope required to fill silk. Charlie's is at 2955-A-3 Cochran Street, Simi Valley, CA 93065; Tel.: (805) 584-0125; Fax: (805) 584-0792.
Reflective tapes and films
Phil Pearce sent me samples of a new product he calls Sky Sheen. It is a very thin and flexible tape which can take small-radius bends and therefore be used on leading edges, providing a "bright strobe light effect" of various colors, depending on the angle of the light source. It sure helps to keep a distant model in sight as it turns in a thermal.
This product complements Skyshine, which is also a bright reflective film but is best used on relatively flat surfaces like fins, fuselage sides, etc. Phil will provide free samples and information for a SASE. Phil Pearce, 111 East Geneva Drive, Tempe, AZ 85282-3638; Tel.: (602) 966-6384; E-mail: 102165.2325@compuserve.com.
Fuel and engine parts
Switching to alcohol fuel for your Ohlsson sideport engine? Victor G. Didelot, who has long provided reproduction timers, needle valves, and other parts for O&R engines, now has metal tanks available at $16 each plus $3 per order for shipping and handling. Address: 4410 Loma Lane, Erie, PA 16506-1422.
Timers
A timer made from a modified drive motor from Tomy toys is offered as a lightweight dethermalizer timer suitable for rubber models by Mik's Models, for $12.95 plus $2.50 shipping and handling. Box 1373, Hollywood, CA 90078.
Adhesives
Super Sam is a nitrate-based product used for adhering covering material to full-size aircraft structures. It is said to be "stickier" than plain nitrate dope, so if you have adhesion problems when covering you might want to try it. It is more expensive than dope, but then you don't paint the whole airplane with it—just stick on the covering material. Aerodyne (1924 E. Edinger, Santa Ana, CA 92705; Tel.: (714) 258-0805) is a source for the product in quart containers.
Klarich kits
Thanks to Mitch Heller for giving me the opportunity to examine a Klarich partial kit for a Miss America. I was very favorably impressed. I think the quality of the kit wood and the cut ribs and other parts are the equal of the P&W kits that left us with the departure of Hobby Horn, which is very high praise indeed. I now feel very comfortable telling anyone who asks that the best deal they can get is to get the plan and partial kit (no strip or sheet wood) from Klarich Custom Kits, 2301 Sonata Drive, Rancho Cordova, CA 95670; Tel.: (916) 635-4588. Catalog of more than 300 kits available for $1.
Coil polarity and ignition system tips
Several newsletters have carried this useful bit of information about the coils we use: polarity (where the hook is positive and negative) is not indicated on most coils, and they will work either way, but they work with 20 to 40% greater efficiency if hooked up right. Connect 1.5 volts to a coil, and measure voltage between the negative connection and the high-tension terminal. If it reads about 1.5 volts, you got it right; if you got it wrong, you will get a weaker spark and shorter battery life.
Art Swift, editor of the always entertaining and informative Flightplug newsletter, offers the following tips for ignition system tuneup:
- Check for battery box contact corrosion, long wires that can "flop around" with vibration, poor solder joints, or other bad connections. He suggests a jumper wire be connected from the timer housing to the crankcase, as oil and dirt can insulate the timer body from the crankcase. Consider replacing the coil and condenser if problems persist.
- If you frequently test your system to see how far a spark will jump, you are likely damaging the coil. Repeated high-voltage build-up fills weak spots in the insulation, resulting in internal shorts that bypass much of the coil winding and make the spark weak. I have also noted that condensers are not replaced often enough, and it is surprising how much difference a good one can make. Better yet, get a transistorized system from Kustom Kraftmanship and forget condensers.
- A better way to check is to remove the plug with the high-tension lead attached, hold the plug against the cylinder, and flip the prop. If the spark is blue and crisp, it's probably OK.
- Art doesn't like the frequently seen practice of using a mini-alligator clip to attach the high-tension lead to the spark plug. His concern is that the weight of the clip puts a strain on the center electrode under heavy vibration—perhaps breaking the seal. He suggests bending a clip from music wire—similar to that once made by Aero-Spark. It was light but had a firm grip.
- Last but not least is cleaning and gapping the points. He suggests using a spray can of TV tuner cleaner (which I used to buy for the purpose from Radio Shack). Some people do not understand the need for a proper gap for the points. A lot of current needs to flow in a short time, so a good low-resistance contact is needed. Plus, due to the design of most timers, the amount of gap affects dwell time.
Transcribed from original scans by AI. Minor OCR errors may remain.
