Here’s a Sneak Peak of the next great construction article from the May 2012 issue of MAN. Designed by Dick Sarpolus, this Zero is easy to build and fun to fly.
To order these plans and build one yourself, got to: http://www.airagestore.com/fun-scale-profile-zero.html
This Fun Scale Mitsubishi A6M Profile Zero is the next step up from simple, lightweight foam sheet airplanes. It features easy to build sheet foam construction and an airfoil-shaped foam wing you can cut yourself of purchase commercially. Information is printed on the plans.
Wingspan: 41.75in.; Length: 31.625in.; Radio: 3 or 4 channels; Power: 150W Brushless outrunner electric motor; LD: 2; 1 Sheet $14.95
A sheet foam profile model offers an awful lot of flying fun for a relatively small investment in material cost and construction time, to those who still like to build their own models rather than purchase an ARF. This sheet foam profile is a little different in that it utilizes a hot wire cut foam wing rather than a flat plate sheet foam wing. I first tried a foam wing on a light profile model as a way to get better flying capability in windy conditions, and I liked the way it flew, so used this construction technique on some “fun” warbird models. They fly well, plenty aerobatic, I like the way they look, and the cut foam wing cores are available at a low cost.
I had earlier done an F6F Hellcat, and some of those who built the Hellcat commented that we needed a Zero to fly combat with it. They were right, the Hellcat and the Zero were a frequent WW II matchup, so here’s the Zero, ready for some combat flying. It’s fun to review and compare the flying abilities of the WW II warbirds, and aviation historians generally agree that for the first couple years of the war, the Zero was about the most capable fighter there was. Its clean design, good armament, and very light weight made it highly maneuverable and tough to beat. But as the allied forces came up with more powerful and better aircraft, the Zero didn’t change, and the Japanese Air Force lost many of its most experienced and skilled pilots due to the lack of pilot protection and self sealing fuel tanks in their planes. By the end of the war, there were a number of fighter aircraft that out-performed the Zero and did a better job of protecting their pilots. Today, the Zero makes a good looking and flying model warbird.
There are a number of different sheet foam materials available that can be used for constructing the model. And for the cut foam wing cores, The Core House offers a computerized hot wire cutting setup to turn out good cores at an even lower cost for a box of four wing cores. Their cores are cut to a standard length of 24”, and you trim the cores for the proper length, planform, and tip shape. I cut the sheet foam parts out with a metal straightedge and a sharp #11 hobby blade. The 1/32” plywood doublers on the nose section really strengthen the fuselage against those rough landings. A carbon fiber tube epoxied in the fuselage adds sufficient strength for the profile construction to work. If you have trouble finding carbon fiber tubes, a piece of basswood or spruce will work almost as well. I have used ¼” x ½” basswood for the fuselage stiffener, sanding/planning it to 5mm thick so it will be flush with the fuselage thickness, if the sheet foam you are using is less than ¼” thick. I use 5 and 15 minute epoxy for the assembly work; I’m always anxious to get the model done in a hurry. Epoxy sticks well to most of the sheet foams, but the types with thin plastic covering on both sides will need a bunch of pinholes poked through the plastic skins where the epoxy will be applied.
I use 1/8” by 3/8” basswood for the wing spars, although hard balsa should also work fine. For assembly of the wing panels to the fuselage, a 1/8” vertical plywood joiner passing through a slot in the fuselage goes into slots in the foam cores between the upper and lower spars. Note, a hole is not cut through the fuselage for the wing – only a slot for the wing joiner, the wing panels butt up against the profile fuselage. Easy and plenty strong.
The foam cores can be covered with any low temp iron-on material. I use the SLC material sold by The Core House – it’s very thin, light weight, irons on easily and accepts just about any type of paint. Hinging all the control surfaces is done with clear packaging tape in the usual foamy model manner. The leading edges of the ailerons, elevator, and rudder are cut/sanded to a 45 degree angle, and the tape applied to the upper surfaces first. Then, with the control surfaces folded upward, the tape is applied to the bottom, pushing it into the hinge gap and sealing it to both edges. This provides free movement and a strong, completely sealed hinge gap.
The servos are mounted by cutting holes into the foam so the servo is a tight push fit, and it is secured in place with a few dabs from a hot glue gun. Hot glue guns are inexpensive and handy for this type of building. Slots are cut into the control surfaces and the 1/16” plywood control horns epoxied in place. For all the pushrods I use .047” wire, with z-bends or the DuBro mini-ez connectors on the ends. Hot glue short pieces of plastic tubing to the fuselage sides to keep the pushrods from flexing. The ESC, receiver, and LiPo battery are mounted to the fuselage with hook & loop tape, and for the battery, I cut slots through the fuselage for a strap of hook & loop material to hold it securely.
I spray paint my foamies with water based acrylic craft paint from most any arts and crafts store, available in so many colors at a low cost. I use a low cost airbrush to apply the paint, and thin it with rubbing alcohol or windshield washer fluid rather than water to reduce clogging while painting. Panel lines are drawn on the aircraft with a marker pen, for as much detailing as you care to do. The correct military insignia, many available in stick-on vinyl, add to the scale appearance.
For power, I use an outrunner brushless motor, about 150 watts for lively performance. I like the low cost BP Hobbies 2212-13 motor and their 18 amp ESC, or any equivalent setup. A 3-cell 1800 mah LiPo pack does a good job, or even larger battery packs could be used for longer flights. The Zero is easily hand launched with an underhand toss at full throttle, and it will fly right up and out of your hand.
Hey this foamy electric warbird stuff is easy and fun to build and fly! There are a lot of other warbirds to be modeled, and I plan to do a bunch of them. What a hobby!
Type - plans built fun scale electric foamy
Skill level - intermediate
Construction - sheet foam, hot wire cut foam wing cores, and plywood
Span/Area - 42”, 350 sq ins
Length - 32”
Wing Loading - approximately 9 ozs/sq ft
Power - brushless outrunner motor 150 watts, with ESC
Battery - 3-cell 1800 mah LiPo
Propeller - GWS 9 x 5
R/C Gear Req’d - 4 channel (or more) transmitter, micro receiver, three sub-micro servos
Stay Tuned! Watch for this upcoming Fun Scale Profile B-25 Mitchell from Dick as well! Looks like a lot of fun!