Free Flight: Duration
Harry Murphy 3824 Oakwood Blvd. Anderson, IN 46011
1991 AMA FF Nationals
The NFFS proposed last October that the Free Flight portion of the 1991 AMA Nationals be held the third week of June at Lawrenceville, Illinois. The AMA Executive Council confirmed the date in late January. We hope future planning will allow a full year of lead time — it would be much less frustrating for all concerned.
The Lawrenceville site dates are June 16–22. Along with the normal AMA event schedule, the NFFS will again sponsor the Nostalgia Gas Championships and several other Special Events. A myriad of Old Timer events will be sponsored once again by SAM 57, and the Flying Aces Club will present neat-flying Scale entries. It should be another great session of Free Flight activity. See you there!
Shopping by Mail
#### Poti's Hangar Products (Norm Poti) Former U.S.A. FAI Power Team member Norm Poti offers custom-made high-performance fiberglass propellers and associated accessories intended for use on high-rpm engines from .15 to .40. Available rigid prop sizes range from 7 in. through 10 in.; the top-of-the-line is a folder with individual fiberglass blades for FAI use. Because folders are expensive to produce, Norm sells individual components separately to offset repair costs from flight damage.
The molding process includes full-length glass strands with fiberglass-cloth tip inserts to prevent splitting or fraying at high revolutions. Props are molded in oversized lengths, so custom diameters and custom designs are available; design work is handled confidentially.
- Rigid props: $7–$10 (unfinished); add $3 per prop for finished product.
- Complete folder: $60; components priced accordingly.
- Send a SASE for a complete price list. Personal attention is given to all inquiries.
Address: Poti's Hangar Products, 5695 Marshall Rd., Dayton, Ohio 45429.
#### Campbell's Custom Kits (Lee Campbell) Lee Campbell returned to full-time operation at Campbell's Custom Kits, producing a steady flow of products for competition free flight. Recent offerings include a new Class A Gas design by Dave Platt and an AB version of Russ Hansen's NFFS Nostalgia Gas–eligible T-Bird.
- Slow Worm (Dave Platt): 432 sq. in., intended for .09–.15 engines; easy to build. Price: $49.98.
- T-Bird (Russ Hansen): 526 sq. in. (50% enlargement of the Half-A model), intended for .19–.25 engines approved for Nostalgia Gas events. Price: $59.98.
- Both kits include ready-cut parts and top-quality wood. Shipping: $2.50 UPS domestic.
- Flexible latex fuel tubing (small diameter, thin-walled): $0.60 per foot — ideal for weak-spring toy timers.
Address: Campbell's Custom Kits, 401 Executive Center Drive H-108, West Palm Beach, FL 33401. Add $1 for the catalog.
#### A.J.'s Free Flight Service A.J.'s Free Flight Service announced a 440 sq. in. kit of Don Alberts' 1955 AMA Nationals 1/2A Gas winner, the S.W.A.T. (originally 200 sq. in., powered by an Atwood .049). The 440 size was engineered by Gene Post and is reportedly the first of three sizes to be produced this year.
- Kit includes machine-cut parts, rolled plans, and accessories. Price: $34.95; UPS to your door $3.
- Also: long-handled needle valve for K&B green-head engines, $2 each plus $0.50 postage (buy five and postage is free).
- Catalog available for $1.
Address: A.J.'s Free Flight Service, 4840 E. Leisure, Fresno, CA 93727.
#### A.A. Lidberg Model Plan Service (Al Lidberg) Al Lidberg's latest rubber-scale plan packet features Charles A. Lindbergh's Miles Mohawk (1 in. = 1 ft., 35 in. wingspan). The packet includes detailed histories and is recommended for Rubber Scale enthusiasts.
- Plan packet: $6 plus 15% postage.
- If you want the plan rolled in a tube, postage is a flat $2.50.
Address: A.A. Lidberg Model Plan Service, 614 E. Fordham Dr., Tempe, AZ 85283.
Reinforced Wing Spars (Norm Poti)
Norm Poti provided instructions for fabricating carbon-reinforced wing joiner spars suitable for FAI F1C power models, where higher aspect ratios and thinner airfoils mean wings must withstand tremendous bending loads. Two-piece wings place the joint at the maximum-load location — the wing center — so joiner strength is critical.
Because 3/32" music-wire wing joiners have worked well for a decade, Poti established a bench test to fabricate a spar that would bend the 3/32" wire before the spar failed. Glues alone proved inadequate; eventually a spiral-wrapping technique using Kevlar thread was developed to transfer loads to the thread, making the specific glue less critical. Materials weights and thicknesses were tailored to optimize strength-to-weight.
An inadvertent field test occurred when a model dove from 1,000 ft and hit a concrete runway at WPAFB. The wing did not flutter or fold; the spar remained unscathed. The spar was rewrapped with Kevlar and reused.
Construction overview (condensed):
- Determine required component dimensions, including the balsa core. The inboard end of the balsa core should be 2 in. shorter than the top and bottom carbon plates to permit a pocket for the brass joiner tube.
- Epoxy a 4-in. length of .007" carbon onto one end of a 12-in. × 3-in. sheet of 1/32" basswood. From this, cut four 12-in. long strips to the desired root width — these will form the spar sides.
- Cut the tapered balsa core from straight-grain 6–7 lb. balsa; sand to final shape from 1/4 in. square or 3/16 in. square stock as required.
- Top and bottom caps: tapered strips of .021" carbon sheet.
- Assemble the spar with cyanoacrylate (CA) cement; final sanding.
- Spiral-wrap the assembled spar with Kevlar thread: 1/8 in. pitch at the root, increasing to 3/16 in. pitch outboard; cement-coat to retain the wrap. A pair of finished joiner spars weighs about 10–11 grams.
- After wing completion, pot a 2-in. length of 5/8 in. I.D. brass tubing into the hollow carbon box end with a mixture of epoxy and microballoons.
This is a condensed how-to. For a full uncondensed article, send a SASE to Norm Poti (address listed elsewhere).
FF Duration / Murphy (Continued)
(Continued material and additional notes.)
FF Publications
- NFFS Symposia (1990): 129 pages of designs, theory, plans, and photos for Indoor and Outdoor Free Flight. Content includes power articles on hi-thrust and winglets; rubber articles on energy storage, winding stands, and power calculators; glider articles on composite structures, molding, spars, and F1A wing design; 3-views and text for the NFFS Ten Models-of-the-Year; and up-to-date listings of Nationals high-time winners since 1922 and NFFS Top Ten winners since 1970. Price: $16 plus $2 postage to Fred Terzian, 4858 Moorpark Ave., San Jose, CA 95129. Non-members add $2. To join or renew NFFS ($15), send to Nat Comfort, 12324 Percival St., Chester, VA 23831.
- Free Flight Forum (British FFF, 1990): 80 pages of articles, plans, cartoons, and photos covering stall remedies, F1A design and construction, magnetic soaring, F1B history, and John O'Donnell's "Tips on How to Win." Price: £8.3 (pounds sterling), payable to Newham Beaumont, Spring Cottage, Spring Street, Epsom, Surrey, KT17 1UH, England. Proceeds largely support the British FAI Team travel fund.
- Vol Libre Canada (revival): A bi-monthly containing at least one 3-view plan with detailed notes, competition reports, technical features, how-to tips, and editorial opinion. Address: Canada Free Flight, 213 Lakewood Dr., Oakville, Ontario L6K 1B3.
Newsletter Spotlight
- Scatter (S.C.A.T. — Southern California Aero Team): Bill Bogart has revived the club newsletter after a short absence. Scatter has 12 annual issues for $15. Address: Jim Wilson, 11030 Avenue D, Redondo Beach, CA 90277.
- Oakland Cloud Dusters newsletter: Long-standing club supporting many Free Flight disciplines and some RC Assist activity. Newsletter subscription: $10. Address: Herb Robbins, 16251 Lilac Lane, Los Gatos, CA 95032-3524.
Anecdote: "I'll Be D...d!"
From the Minneapolis Model Aero Club newsletter: a Rubber Scale modeler reported building a perfect early Curtiss pusher with a rubber motor so powerful that when it unwound the fuselage collapsed. The modeller exclaimed, "I'll be d—d!" The club secretary censored the remark as "I'll Be D...d!" which is how it was recorded.
Miscellaneous Notes & Tips
- AJ's Free Flight Service announced a new kit venture for June 1991. Contact the publisher or A.J.'s Free Flight Service for details and availability.
- Tissue-covering experiment: Attempts to substitute Fibe-Mini (a tissue relaxer) with household items gave mixed results. Dissolving Metamucil and applying it to tissue-covered frames produced warping similar to plain water. A 50% Fibe-Mini/50% water solution relaxed the paper without warping fragile frames. Full-strength Fibe-Mini greatly relaxed severely warped tissue. The search continues for an alternative to Fibe-Mini outside specialty sources.
- WACO collectors: The International WACO Association has launched a quarterly magazine; first issue is 24 glossy pages with historic and restoration articles, photos, engine installation prints, and owner-sourced information. Membership: $25 ($35 Canada/foreign). Address: P.O. Box 2065, Terre Haute, IN 47802.
- Corner wrinkle remedy: Prevent wrinkles where tissue bridges a sharp angle by gusseting or bracing before covering. Alternatively, use Paul McIlrath's treatment: with a sharp razor blade, cut a 1/16–1/8 in. slit at about 45° across the corner to provide stress relief. Over time the tissue relaxes and the wrinkle will disappear.
Transcribed from original scans by AI. Minor OCR errors may remain.
