F/FSport
by david mitchell You can reach David Mitchellat 230 Walnut St. NW, Washington, District of Columbia 20012, or via e-mail at
davedge@me.com
PHOTO: PETER KAITERIS
PHOTO: ANDREW RICCI
Maria Kondrat proudly displays her Ambrosini (above left) after winning WWII Mass Launch at the Barron Field Air Races in Wawayanda, NY. Sofia Ricci (above center) holding her freshly minted Delta Dart. Andrew Ricci reports: “The smile nearly went all around her head as her creation took to the
T
he turning of the tide: We lead this month’s column with good news for all those people who worry about how a few well-seasoned experts seem to run off with all the trophies in FAC competition. This October at the Barron Field Air Races in Wawayanda, NY, the heavies were out in force: Tom Hallman, Eddy Pelatowski, John Houk, Wally Farrell, etc.; you know ..., those guys. So, who do you think won WWII Mass Launch, possibly the most heavily contested FAC event of them all? Canada’s Maria Kon- drat, that’s who. Undaunted by howling winds and stiff competition, assisted by her dad, Gerard, and brother, Luke, and with a little pre-event coaching from Mr. Farrell, she trumped the field over three rounds with her beautiful Ambrosini. That, my friends, is not easy to do! Coming on the heels of her eighth-place finish in Embryo Endurance at the 2013 FAC Non-Nats, it’s clear Maria is becoming a flyer to be reckoned with. Lest she rest on her lau- rels however, Andrew Ricci (clearly smarting after limping in at third place in WWII at Wawayanda) let it be known that he is grooming his own daughter, Sofia, to give Maria a run for her money in the near future. Hmmmm.... come to think of it, we also re-
cently saw young Erika Escalante place an extremely respectable nineth in the Simpli- fied Scale event at the Non-Nats, and here in D.C., any old grizzled contest vet who’s run up against Henry Guth at the National Building Museum indoor flying contests over the last few years got the sort of lesson in humility that only a teenager can admin- ister. See what can happen when you take a kid flying? Good work, you guys!
52 Knock it off
There are any number of reasons you might want to make a model with knock-off wings— ease of transport and storage probably tops the list. There’s also the always knotty prob- lem of mid-wing aircraft, which often cannot have a one-piece wing running through the fuselage because of interference with the rub- ber motor. These models have a tendency to shear off one wing or the other until the fuse- lage is mangled, the wing destroyed, or both, and your pride and joy becomes yet another might-have-been hangar queen.
Whatever the reason you decide to engi- neer one, a well-thought-out knock-off wing joint can be a real boon to a model’s longevi- ty, and with a little care need not come at too high a price in added weight.
Mike Stuart is well-known for his beauti- ful and unusual models. A visit to his web- site (
http://www.ffscale.co.uk) is a must for anyone interested in exploring what free - flight has to offer the adventurous modeler. Whenever possible, Mike makes the long trip across the pond to compete at the FAC Nats in Geneseo, NY, which means many of his models are designed to break down for transport.
He sent me photos recently of his latest project, a stunning Beechcraft King Air, which illustrate beautifully the mortise- and-tenon style knock-off joint he developed for the model. A plywood tongue is integrat- ed into the outboard wing panels; this fits into a simple, sturdy box that is built into the wing center-section. Paper is glued to the face of the plywood tongue as needed to make the joint a bit tighter, but not too tight. You want the outboard panel to knock away in the event of a hard landing!
PHOTO: MIKE STUART
air. She was able to launch it herself with pretty good success. I’m a happy dad today, indeed!” Close up (above right) of the knock-off arrangement on Mike Stuart’s King Air. The boxes provide necessary structure at this high- stress area.
Note that the front edge of the tongue is heavily rounded to allow it to disengage without destroying the box. The assumption here is that the wing panel will be knocked backwards, and that it will pivot off the trailing edge.
A bit of experimenting with the assem- bled wing will show you the geometry need- ed for your particular application. This is a very effective type of knock-off joint that has the benefit of being quite stiff on the horizontal axis, so long as the joint is kept a close fit.
Magnetic attraction
The use of “rare earth” neodymium mag- nets has been on the rise in F/F since the late ’90s, when the little powerhouses start- ed to become more affordable. Now widely available in a variety of shapes and sizes, and reasonably cheap, you’ll find them being used in all sorts of applications in F/F mod- els—including knock-off wings. Mike Isermann is another modeler with a hangar of “travel models” that need to break down for transport. He used rare earth mag- nets in concert with a carbon-fiber spar for a lightweight and effective break away joint on his beautiful 25-inch Martlet Mk II. The 5⁄16- inch diameter magnets supply lots of holding power, but are not strong enough to prevent the wing from blowing up (or down) on the horizontal axis—there’s too much leverage there.
That’s where the carbon fiber spar comes into play. It’s a close friction fit into both the wing and the fuselage but is left removable in the event the spar breaks. A small dowel pin towards the trailing edge insures that the wing incidence stays set.
DECEMBER 2013
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