Author: Gene Smith
Edition: Model Aviation - 2010/05
Page Numbers: 124,125,126
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Mike Isermann’s Brown Racer

Free Flight Sport — Gene Smith [[email protected]]

Mike Isermann’s latest mount for the Flying Aces Club (FAC) Greve races is the Brown Racer. It spans 18 inches, weighs 21.5 grams, and sports a 7-inch carved propeller. Those are the numbers you like to see for a good-performing model.

I always liked the looks of the Brown Racer but shied away from it because it was most commonly shown with fixed landing gear — a definite handicap for duration. However, I found out that the Brown Racer did compete one year with retractable landing gear. There was trouble with the retractable-gear system, and it was converted back to a conventional undercarriage the next year. For FAC competition, though, a retractable-gear version such as Mike’s is the way to go.

Chris Holford is one of many British free-flight modelers who enjoys Ebenezer models: simple profile designs that use small engines. Although Chris’s Hurricane is a bit larger than the average Ebenezer airplane, it’s a great representation of the type.

The Hurricane spans 36 inches. Chris arrived at that size by scaling the plans to use the largest size of paper his printer could handle, which was 13 x 19 inches. The model weighs 18 ounces. Chris knows it could have been lighter, but he covered the tail twice to hide his experiments with printing! The extra weight in the tail made him add a fair amount of lead to the nose to get a reasonable balance point.

Chris built in 2° of right thrust, but he might add more because he had to put a small tab under the left wing to keep it up. During initial flights, the Hurricane flew in a big left-hand circle under power and the glide was almost straight. The airplane’s PAW .55 uses a 7 x 3 Graupner propeller. The little 1/2cc diesel has to be set to give nearly full power, and the rate of climb is not so great. However, the Hurricane was able to rise-off-ground (ROG) after a long run on short, level grass. That had to be a sight!

Chris chose to model the Hurricane wheels down, because he thought that would keep the CG low. It’s great to see an FF model ROG! The aircraft was constructed from light balsa and covered with printed paper (not tissue). Chris finds that this makes a rugged model. Two thin coats of nitrate dope completed the job, and that is okay to use with diesel fuel. He was unhappy with the printing on the “silver” paper, because it tended to smudge with handling. Chris has tried printing the panel lines and other markings on plain white paper and then dusting them with silver paint from a rattle can. This looks promising so far.

The wheels are balsa with thin plywood discs on either side at the hub. The tires are made from an elastic tubular support bandage dyed gray.

George White’s P-39

George White spent more time than he would have liked rebuilding his Golden Age Models P-39 kit to get the wings set the way he wanted them. He took the model to the field for testing and, much to his astonishment, it flew beautifully off the board.

George did a little fine-tuning, with only two half-turn adjustments to the GizmoGeezer adjustable nose button. The P-39 flew so well that he would have lost it had it not been equipped with a DT.

The model is a bit on the heavy side, at 48 grams. George attributes the extra weight to too much paint and the addition of planking to fair in the fuselage below the wing. He used the Neelmeyer 10% airfoil rather than the thick, symmetrical airfoil shown on the kit plans. George believes that the airfoil plus the high-pitch Jason’s deli-cup propeller blades are the secret of the model flying so well.

George got so tired of the rebuild that he nearly trashed the model. Now he is glad he didn't! He is experimenting with a 15% motor made from four strands of 3/16-inch rubber for the limited-motor-weight mass-launch event.

While at Geneseo, New York, for the FAC Non-Nats last year, Paul and George were very impressed with the workmanship of all the models that Pat flew. Part of the secret to his airplanes is that he owns a CAD design company that specializes in fire-protection design, so he has computer skills and graphics software.

Pat's Stinson Gullwing has Pepsi markings matching those of an aircraft that was flown in the 1930s. All of the markings are computer-generated. Pat cannot only build models, but he can also fly them. He won the World War II mass launch with his Grumman TBF Avenger—quite an accomplishment flying against the more streamlined inline-engine fighters.

Foam Towline Glider

I mentioned Bill Kuhl's website several years ago, and it's time to mention it again. It's an excellent resource for free-flight beginners and sport fliers.

The project that attracted my attention was the large foam towline glider. You have probably seen the cheap gliders that are sold in hobby and toy stores. Bill modified one of those with a rudder tab and an offset tow hook, which made the model a simple towliner.

I tried the same thing with a similar glider, with mixed results. My problems began when I discovered that the fuselage halves had been sloppily assembled, resulting in a difference in incidence between the two wings. That took cutting and shimming to correct. The nose was longer than needed for reliable towing, so I shortened it and added ballast to the nose to adjust the CG.

There was also inadequate dihedral. The wings were too weak to survive a tow in any but the lightest wind, so I strengthened them with nylon-reinforced packing tape. Flight tests await the addition of tip dihedral and better weather.

David Mills built his Super Talon Towline Glider from Don DeLoach's kit. David slightly modified the kit by adding geodetic ribs for bracing in the wing and stabilizer. The wing is now as stiff as a board. David reduced the stabilizer area from 16% to 14% so that stabilizer incidence could be increased to aid stability.

David noticed that his Super Talon rights itself quickly in turbulence. He suspected at first that the fin might be too small but has had no problem with Dutch roll. He initially used a rubber-band wing-mounting system but returned to Don's original concept of adding a platform under the wing trailing edge that allows incidence shims to be added. Each wing panel is secured with a shearable 4-40 nylon bolt — a system that works really well.

David hasn't decided whether or not this large and light glider has a real advantage in Classic Towline, but he does know that the Super Talon looks and flies great. It's like cranking up a Super D. All action on the field stops when you tow up this beauty.

Don sold out of his original run of short kits for the Super Talon, but he is taking preorders for another kit run in May or June of this year. The price is $150 plus postage.

The Super Talon kit includes everything but covering, timer, and straight balsa. It has plans, four carbon wing spars, a tapered carbon tailboom, and 16 sheets of laser-cut parts.

Don also sells laser-cut ribs for his Polecat P-30 (plans are $7 and a rib set is $8) and a short kit for his Yak-3 ($15). The Yak plans are available from Flying Models magazine.

Dohrm Crawford decided to take the towline plunge with a Swedish design: the Sunnanvind old-time glider. The plans are in Swedish, which led to all sorts of machinations to figure it out accurately. Dohrm is planning to fly the Sunnanvind at this year's SAM (Society of Antique Modelers) Champs at Muncie, Indiana.

If you want to see an excellent tutorial about covering a model with tissue, go to the Guilows website, click on the message board link in the middle of the page, and open the "Building another Messerschmitt" thread. The text and pictures tell the story exceedingly well.

Thermals! MA

Sources:

Transcribed from original scans by AI. Minor OCR errors may remain.