E-Foamy’s
EDGE 540
This simple to construct, tough,
foam electric is up to the challenge of teaching aerobatics!
By Daniel Walton PHOTOGRAPHY: DANIEL WALTON T 58
his project found its roots in the usual act of desperation associated with a lack of time and too many other pressing issues. The basic kit
is marketed by
e-foamy.com and is one of a line of kits for this type of plane produced lo- cally by several enterprising spirits. The kit comes in a long thin heavy plastic bag (rem- iniscent of one of the all balsa F/F rubber powered Sleek Streek type models) with all the precut and pre-shaped pieces loosely in the bag along with the materials for the spar and pushrods as well as pre-bent and cut .032 piano wire ends and some lengths of heat shrink tubing to be used for attach- ment to the graphite pushrods. Also in this bag is a very brief set of gener-
ic instructions for the models put out by this company, which include a Yak 55 in 32- and 54-inch span sizes, an Sbach in 32- and 54- inch span sizes. The Edge 540 in both the 32- and 54-inch span sizes as well as a su- per simple trainer with the prop mounted in
the middle, a flying go-kart, and an F-117 fighter kit, of all things, in their product line. If you want more information on these
other offerings they can be viewed at www.e-
foamy.com where you can find all the perti- nent information as well as pricing and ac- cessory kits, servos, motors, tips and builder information along with other links to infor- mation on the internet. I chose the 32-inch Edge 540 “beefy” kit
(1.9 pounds per cubic foot density, versus 1.3 pounds per cubic foot density EPP foam) for several reasons, not the least of which was the graphite straps along the rear horizon- tal portion of the fuselage between the hor- izontal tail and wing. I knew that there were a lot of different techniques that I would have to master in putting one of these air- craft together as well as the flying technique required being quite different. If you have ever seen one of these aircraft in “flight” it is not like your “normal” airplane.
Much of the flying is done using vectored
thrust from the big electric motor powered prop and the control surfaces move quite drastically to achieve this as well as being re-proportioned to have much larger moving areas. They also have no aerodynamic cross section whatsoever (all the aerodynamic fi- nesse of a barn door). They are just simple big flat plates with no taper from an aerofoil standpoint and only a bevel along the hinge line to accommodate movement in that di- rection. So a very rugged “beater” was the order of the day. After a couple of years of watching these
models fly, another characteristic became very noticeable. Their durability in the face of some fairly punishing abuse. The EPP foam that these models are made of has a very rubbery quality to it. Not at all like the brittle characteristics of foams like the styrene type. It also makes the material a little more interesting to cut. You will need a very sharp razor blade or X-Acto knife to
DECEMBER 2011
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