One of the quickest ways to the finish line on one of these models is to start by cutting out all the parts from the foam sheets and make sort of a kit. This picture (above left) shows the lower fuselage and upper fuselage with fin (both of the 1.9 pounds/cubic foot density material) and the rudder (1.3 pounds/cubic foot density material). Next, the main portion of the wing and the two elevons


gether as well as the flying technique re- quired being quite different. If you have ever seen one of these aircraft


in “flight” it is not like your “normal” air- plane. Much of the flying is done using vec- tored 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 finesse of a barn door). They are just simple big flat plates with no taper from an airfoil standpoint and only a bevel along the hinge line to accommodate movement. 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


(above right) are fabricated from the 1.3 pounds/cubic foot density foam material to keep the rear end light while the forward portion of the wing, which will mount the servos, is fabricated from the 1.9 pounds/cubic foot density foam material. This gives the extra strength needed as well as adding some weight to the nose where it is required.


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 do a nice job of cutting this material if you want to pursue a design of your own. This is another reason I decided to start


with the prefabricated kit. All the major components were precut and beveled for the hinges and I was assured of some success for early flying efforts as this type of model flies so differently. I also have an Extra 232 from the E-flite line of kits, but being made of bal- sa and plywood with film covering, a crash would result in a major rebuild or complete scrapping of the model. Not so these EPP foam planes. They are


more like some child’s “Nerf” toy. Crash it, step on it, kick it, whatever (within reason- able limits but still not recommended), it


springs back to its original shape and is ready for more abuse. The worst damage is usually a broken plastic slow flyer prop if the prop saver O-ring is not up to the task on that particular impact. It’s more like a flight simulator than a model airplane in this respect. A very different way of think- ing that encourages pushing the edge of the envelope for a lot of flyers. One becomes more daring when there are


fewer penalties and less to lose. The profile models made from some of the other mate- rials, while lighter, seem to be more prone to damage and this was one of the other things that finally drew me to this particu- lar type of construction. I have very little time any more for rebuilding some elabo- rate model if an inadvertent mistake is made, mostly due to pressures from the work-a-day environment. Another paradigm that you will have to


Details for mounting a control surface (above left) are fairly simple, but there are a few tricks. Line up the two parts to be joined and tape them in place on the far side of the hinge with a couple of straps of the masking tape. Then turn over and mask off a location about 3⁄8 inch from the hinge line on either side of the hinge line. Also mask off the end near the “balance horn” on the rudder to keep any excess adhesive from gumming up the final works. Apply a bead, about 1⁄8


FLYING MODELS


inch diameter, along the hinge line and spread it out using an old playing card or other similar device as a squeegee to spread the glue into a thin layer and let it cure. Install the 4mm graphite tube spar (above right) into the lower surface of the wing and let it cure. When cured, test fit the elevons to the wing and the forward portion of the wing. Use tape across the bottom of the wing to jig them in place so they will be held in proper location for the hinging operation.


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