Radio Control: Old Timers
AFTER competing in the World Scale Champs in England, Bob and Dolly Wischer remained for two weeks touring the countryside, finishing up at Old Warden Aerodrome where a "meet" was held for Old Timer free flight and RC. Officially titled The Aeromodeller Vintage Meeting, the annual event also marked the Golden Jubilee for the Lord Wakefield cup. The Wischers have provided some superior shots of some out-of-the-rut designs that we shall share with you for the next few issues. Two of those photos are of two Vulcans, a 1944 design of D.A. Russell. The late Mr. Russell was for many years editor and publisher of the English magazine Aeromodeller, and the construction drawings are still available through the mag. Russell's drawings show a Dennymite .57 ignition engine manufactured then sold in the U.S. by movie idol Reginald Denny. (See Dennyplane, MA Jan. 77 for details.)
Bebe Jodel D.9
LONG a popular design for the homebuilder, the Bebe Jodel D.9 offers the same advantages to the modeler-attractive lines, ease of construction, and excellent flight characteristics. Originally designed by Jean Delemontez and Edward Joly in 1948, the plane has undergone continuous refinement and modification since that time. The plane has been certificated with numerous engines ranging from the D.9 with its 25-hp Poinsard, through the D.92 version with a modified Volkswagen engine, and on up to the two seater D.119 with a 90-hp Continental. All versions are low wing, featuring a one-piece lifting section with a constant chord center portion and tapered wing tips, each set at a dihedral angle of 14 degrees. The fuselage and tail units are of wood construction with fabric or plywood covering.
Radio Control: Old Timers
JOHN Tedford of Spearville, Kansas is flying his "Utility" in the free-flight mode, using a 1.5 cc Cox, but anticipates converting to 2 or 3 channels in the near future. The Utility should make a superior trainer for his first attempts at R/C Old Timer flying. Although a 2.5cc powerplant would be SAM legal in the model, the concept of powering this design with a Cox Conquest or a Rossi 15 strikes fear in my heart. The resultant climb should surely rival that of an FAI power ship, even at an increased wing loading of 10 oz./ft.2 rather than the 6.55 of the FAI rules. Construction of Hackers Utility is typical for the period. The wing ribs are 1/16 sheet, the spars 1/8 × 1/2 and 3/16 × 3/8, the leading edge 1/4 × 1/4, and the trailing edge 1/8 × 1/2. I would recommend substituting a larger T.E. and use of four spruce spars if a larger powerplant is contemplated. Tail surfaces are of 1/8 outlines with a 1/4 spar, the semi-symmetrical section sanded in after assembly. The fuselage is a 3/16 sq. box with formers and stringers contouring the bottom. I would consider substituting spruce for the longerons. The nose is carved from 1/2 balsa sheet. The undercarriage could be improved upon with a Kadet type torque rod main gear, or a torque-bend type as used on U/C models.
Radio Control: Old Timers
MANY builders of Old Timer RC-assisted models have successfully scaled designs up or down from the original. I have had gratifying results reducing the Powerhouse to 85%, the Ole Reliable to 60%, and the Westerner and Scram to 50%. I have also been satisfied after enlarging the Viking and the Panther. However, such scaling does not always result in a model with the same flight characteristics as the original. This month's feature illustrates such a deleterious result. In 1940 Henry Struck designed a new model to meet the requirements of the 1940 rules. Wing loading requirements had been removed and an 80-oz./cu. in. of displacement rule introduced for 1940 competition. Struck named his model the New Ruler. With a .60, the model was required to weigh 48 oz.
Radio Control: Old Timers
REPEATEDLY over the last few weeks I've begun to compose this report only to question my objectivity in light of overwhelming enthusiasm. Can the Davis Diesel conversion heads actually alter the characteristics of a glow motor to the extent my testing indicates? Do these conversions represent a valid improvement in power, torque, economy, and utility, or am I allowing my fondness for diesel powerplants to cloud my judgement? Admittedly, I am certainly not an engine expert, do not possess the equipment to accurately measure performance, nor have I ever been very interested in modifying engines. In the final analysis, the only important measurement of any powerplant is its performance on a flying model. This is exactly where the astonishing performance change comes in with the Davis head and the answers are all decidedly positive. The Original Buccaneer in the photo spans 84 in., has a chord of 14 in., weighs nearly 7 pounds, and will take off short grass in less than 10 feet! It will gain altitude at 60% throttle, cruise at 40%, and with the Semco muffler is barely audible 100 yards away. The powerplant is turning a 13 × 6 Rev-up prop 10,000 rpm, idling at 1800 (measured with Heath-kit tach). Now for the incredible number. This "Bucc" is not powered with the usual 60 glow; the engine is a ST 35 Stunt!! Unbelievable you say! Not with a Davis head.
