The basis for the wing mount—new balsa cross pieces (above right) between the cabane struts with super magnets. Two super magnets added to the lower wing saddle (above right). By making the lower wing removable, the radio receiver can be put under the wing, rather than into the crammed servo compartment. Tail balsa spanner (below left) and hold
down super magnet. The heart of the quick breakdown flying wire system (below center). Magnets piggy back under the main wing hold down magnet. The magnets (below right) can be slid to each side and the flying wires removed. All that must be done now is unhook the barrel swivels from the soft aluminum rod hooks.
my flying skills. I am self-taught and have usually spent more time at the building board than at the field. My flying field also has some of the most mobile trees I have ever encountered. At first, I was happy to simply be able to easily take apart my air- planes for repairs after an incident. Then, it struck me that if certain of the traditional strengthening points could be designed to fail, I wouldn’t have to repair as often or as much. The composite of this design is purely
mine, but I suspect that many of the compo- nents have been based on other designer’s ideas. Where I remember the origin, I give credit where credit is due, but it would be humanly impossible to remember all of the seeds that have been planted by the hun- dreds of articles and plans I have reviewed in over 50 years of modeling. And I am happy to report that the modifi-
cations only require a few dollars in addi- tional expense, about an hour more at the building board, and can be performed by novice builders with only a few basic tools.
Mods to the instructions Get rid of the epoxy: This kit consists of several finished component groups, which must be trial fitted and then glued together. That’s all there is to it. The kit engineering is excellent and the components fit well. The problem is that everything is epoxied to- gether. I love epoxy for its strength, ease of use and speed. But it is heavy and makes un- forgiving joints. So I cut its use to a mini- mum: small dabs of it for the super magnets
FLYING MODELS
and the balsa sticks that bridge the cabane struts and the fuselage. The magnets are epoxied into the new bal-
sa “spanners” for one side of the attachment points, and into the “sockets” that are cut through the plastic egg shell covering and into the foam, for the other side of the at- tachment points. These form my key “break- away” points: wings and tail feathers to the fuselage. But, in order for the break-away points to function smoothly, other minor modifications are also needed, including to the flying wires and landing gear. I have played with super magnets for a
number of years. So far I have not had a flight failure, and have had a number of oc- casions where they saved repairs on several of my airplanes. The flying wires also have the ability to let
go at extreme g-forces. That’s why ¹⁄₃₂-inch soft aluminum rods with open hooks are used. As long as we have a progressive se- ries of things that hold the airplane togeth- er, things should work fine at “crunch time.” On two occasions, my Moth has rolled off
my garage workbench and taken a nose dive into the concrete floor. On both occasions the magnets shifted momentarily and the flying wires on one side unhooked and allowed the upper forward wing to swivel at impact. These were not planned tests! Meet the magnets: The wing attach-
ment uses super magnets that are approxi- mately ³⁄₁₆ by ¹⁄₁₆ inch and exactly 5mm by 2mm. There will be one at the trailing edge of the upper wing and two at the leading edge of the upper wing, and then two at the
trailing edge of the lower wing, and one at the front of the horizontal stab. And where the wing and tail magnets meet their mounting points are greeted by their com- panion magnets in the fuselage. The bottom wing uses the jigging slot at
the front of the lower wing saddle to hold it in place by allowing the wing to be keyed into it. Reinforce the “key” on the front of the wing with clear shipping tape, top and bot- tom times two thicknesses. Finally, the flying wire attachment sys-
tem will also use two magnets, for a total of fourteen of the larger magnets. Four tiny magnets are used to stabilize the tail. They are ³⁄₃₂ or 2mm long by ¹⁄₁₆ or 1.5mm long, or in that ballpark. Meet the quick detach flying wires: In addition to the super magnets, the wings have quick detach flying wires. (Yes, I know that the location of the barrel swivels and aluminum hooks is technically on the land- ing wire side of things, but I have always liked the term “flying wires” better, so am taking poetic license.) Look at the photos and you will see how they work. If we start at the bottom of the flying wire
runs and end up at the top end you will see that I follow the stock design of having the wires go through the bottom wing, but, rather than anchor them on little dowels un- derneath the bottom wing, they are tied to soft aluminum circular keepers that have small rubber bands tying both sides of the wing’s flying wires together. At the end of their runs, at the rear of the upper wing center section, they are at-
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