Great Planes Piper J-3 / L-4

Supermodel Melanie Blattenberger with Kirt's Great Planes Cub 20 finished in L-4 Grasshopper military colors. Futaba 6-channel radio - Airplanes and Rockets

With 3 sizes to choose from, there's a Cub kit to suit any modeler's tastes and budget. But they all share the benefits of Great Planes' advanced engineering, resulting in models that are amazingly easy to build and fly. And with scale outlines taken from original Piper 3-view drawings, these kits boast a very realistic Cub profile, with incredible attention to detail. All 3 Great Planes Cub kits feature computer-designed and drawn plans, interlocking die-cut wood parts and straight, strong structures. Building is further simplified by pre-shaped leading edges, pushrod routing holes and virtually all-balsa exteriors. The 40- and 60-size Cubs feature barn door ailerons; the 20-size has strip ailerons.

Here is some info on my Herr Engineering J-3 / NE-1 Cub.

My latest Great Planes Cub 20 was modified to produce an L-4 Grasshopper in D-Day invasion colors. It has scale barn-door ailerons (vs. the strip ailerons provided) and observation Plexiglas in the rear. Philip Blattenberger holding my Great Planes J-3 Cub 20 (1996, Syracuse, New York) - Airplanes and RocketsA micro servo was installed to trigger a small digital camera on the left wing struts. The stock version was covered in red, white, and blue with a non-scale scheme.

Close-up of barn door aileron linkage for L-4 Grasshopper. Kirt BlattenbergerClose to a decade ago, I built a stock GP Cub 20 in classic yellow, flew it a dozen time or so, then sold it.

More recently, I built and test-flew a GWS electric J-3 for a friend of mine. It uses a  Hitec 3-channel radio.

Believe it or not, I'm putting the finishing touches on another GP Cub 20 that sports a red, white, and blue Monokote job. On this version, I mounted the engine upright because I am tired of the fickleness of an inverted engine. Sure, it's not as scale-looking, but then neither is turning the thing upside-down to start the engine.

Framed-up Great Planes Cub 20 kit, with modifications for barn door ailerons and the rear observation windows - Airplanes and RocketsDave Guzman, a friend and professional comrade (electrical engineer, owner of RfTek) of mine from the Raleigh, North Carolina area, built and flew model airplanes as a boy in Columbia. A picture of his Fokker DR-1 triplane, one he build many moons ago, is shown to the left. The J-3 Cub to the right is one he asked me to build and test-fly for him since it had been so long since he had flown anything. I gladly took on the task.

He bought a Hi-Tec 3-channel radio for it. As with the GWS Tiger Moth that I had bought for myself, the GWS J-3 Cub needed some structural improvements to make it more durable. I cannot recall exactly what changes I made, but one was definitely to NOT use the crappy glue that is provided in the kit. Reinforcing of the wing strut attachment points was needed, and learning from the GWS Tiger Moth, about 5 degrees of down thrust was built into the motor mount. The Tiger Moth had a severe tendency to climb in a when the power was advanced past about half throttle. It turned out being a good decision, because even with the much down thrust, the GWS J-3 Cub still liked to climb at high throttle settings.

GWS J-3 Cub (2004) - Airplanes and RocketsI took the J-3 Cub along to a small party that Dave and his wife threw at their house, and after eating, we all walked across the street to for the maiden flight. The radio was range checked, a quick preflight on the structure, and it was tossed into the air. Thankfully, the crowd was treated to a perfectly trimmed and flying airplane. After a few trips around the field I put it into a dive and pulled up into a really bad loop, but everyone was happy to see it. It flew around doing low passes until the battery ran out of power and made a nice landing in the grass. It was getting really dark by then, but we stuck in the other battery and heaved it into the air again. Dave flew it for a short time, but it was difficult to maintain visual orientation with the low light, so he handed the transmitter back to be and I flew until the battery crapped out.

Great Planes J-3 Cub 20 w/O.S. 25 LA

The Great Planes J-2 Cub 20 with non-scale covering scheme - Airplanes and RocketsO.S. 25 LA installation on Great Planes J-3 Cub 20 - Airplanes and Rockets

Here is my non-scale covering of the Great Planes J-3 Cub 20. It was originally covered in an L-4 Grasshopper scheme, but my lousy eyesight made it hard to tell what was happening due to the lack of color contrast, so I re-covered it as shown. While at it, I turned the O.S. 25 LA engine upright to eliminate the need to turn the darn thing over to start it (flooded otherwise). I also fixed the ailerons in place to make it a 3-channel setup - the aileronsRadio Compartment Great Planes J-3 Cub 20 - Airplanes and Rockets were not very effective, so I figured why bother. Great Planes J-3 Cub 20 Radio CompartmentMounting the engine far enough out on the mount to reach front resulted in a lot of springiness, so I moved the engine back close to the firewall and added a prop shaft extender from Fox.

The current setup is for a Futaba radio with three S3004 standard servos. There is plenty of room for any radio. A 6-oz. fuel tank is installed and pressurized by the muffler. I'm going to convert it to electric power.

 

 

Great Planes J-3 Cub 20 Low View - Airplanes and Rockets          Great Planes J-3 Cub 20 Windshield Attachment - Airplanes and Rockets

Great Planes J-3 Cub 20 Tail Bottom View          Great Planes J-3 Cub 20 Top Rear View - Airplanes and Rockets