In this article, I will describe the construction phases of the
Table of Contents
3DLabPrint Piper J-3 Cub
model designed by 3DLabPrint, which is currently available for free download, the printing process, the minor issues encountered during the construction, and the model’s behaviour after flight, its resistance and its fracture toughness.
About the company:
- They are engaged in filament manufacturing, designing and selling 3d printed models.
- One of its two founders is Stepan Dokoupil, a professional aircraft designer who has been in the business for 15 years, and the other founder is Patrik Svida who is a world champion in air combat competitions won with a model of his own design.
Files can be found on the 3DLabPrint Printable airplanes Archives – 3DLabPrint link and can be downloaded after registration. I can’t remember exactly, but you may need to set up payment information. Offered model is free to download no money will be deducted by the company for it from your account.
PLA:
- PLA filaments (PLA is short for polylactic acid. A plant-based, compostable material made from plant sugars. It can be made from corn starch, cassava, sugar cane or sugar beet) or
- LW-PLA filaments is a special version of PLA, called foaming PLA , which foams depending on the temperature, so that different thicknesses can be achieved at different temperatures. Of course, because it foams, the same wall thickness as conventional PLA can be achieved with about half the weight. This material is a strange material, papery to the touch, it crumples rather than bends, not very strong at first but when printed properly it can create a surprisingly rigid structure.
Both PLA filaments and LW-PLA filaments are available here.
Printed elements
Frist step, fuselage.
The first thing I started to do was to put together the trunk. As a glue, I used plain ( dilute to medium thick) superglue with CA activator. Joining the first two elements is a bit tricky, it’s not clear at first what fits where, what has to slide in where. One of the drawbacks of LW-PLA technology is that because it foams, the exact wall thickness is difficult to set. A wall thickness between 0.4 mm and 0.6 mm is ideal. In this case the elements can be slid together without any particular difficulty.
Wing and controls
The individual elements of the wing should be sanded over with a small piece of wood or sandpaper (160/180 ) glued/ gripped on a flat – hard flat surface, and the joints should be straightened with a sharp thin knife – scalpel. After gluing the wing together, you can also use a piece of printer’s tape for the stiffening and hinges, as recommended in the factory instructions.
Electronics , the first impressions
I painted the Piper J-3 Cub with duplicolor spray paint, for the decoration the manufacturer gives you a sample that can be printed and cut out in places where they can make decals.
The RC model comes with 4 standard 9 gram servos which are perfect for flying.
Power was provided by a 30 A regulator and a 1500 mA LIPO battery with a 6 channel receiver. The plane is surprisingly stable, a quiet beginner’s plane. I did not experience any negative behaviour during the flight and I can recommend it to beginners who want to learn to fly with rudder and rudder control.
The centre of gravity with the above mentioned electronics is in the place recommended by the manufacturer, I did not have to put any extra weights in it. Negative is that with this runner, the “high” grass does not like nose dives, which brings with it the possibility of damaging the top of the rudder. Of course it can be repaired immediately if we have superglue.