LF-107 Luňák


LF-107 Luňák


A giant 1/5 scale, almost 3m wingspan 3D printable RC model of successful Czechoslovak post-war aerobatic glider LF-107 Luňák designed by Julien Watier. The plane has a very rigid construction and mass to keep the energy, as a result, it’s capable of very aggressive aerobatics and high speeds. The nose of this model can accommodate an electric motor to allow hand launching, but at the same time the propeller can be easily removed and a tow hook mechanism allows the plane to be towed by a tug plane to enjoy a pure glider performance. Despite it’s higher mass required to keep the energy in aerobatic manoeuvres it’s also quite a capable thermal glider. To improve the thermal performance, some parts can be printed from LW-PLA.

What you get:

  • STL files
  • 3mf and factory files with all the slicing settings for Original Prusa MK3/S printer
  • Presliced Gcodes for Original Prusa MK3/S printer
  • DXF file with decals template
  • STL, 3mf and gcode file to print a vacuform mould for optional clear canopy

What you need:

  • A 3D printer with a diagonal of at least 290 mm and 210 mm Z height, Original Prusa MK3 recommended (250x210x210)
  • 3-4 kg of PolyAir 1.0 (highly recommended) or PLA, LW-PLA as an option for some parts, some Flex for tyre
  • Slicing software: Simplify3D required for surface body parts (factory), manifold parts can be sliced in Prusa Slicer (see the user guide for more info about profiles)
  • Carbon rods, tubes and brass tube (see the user guide for the complete list)
  • A pull-pull mechanism for rudder control
  • 3x standard-sized servos
  • 4x flat 30x10x35,5 sized wing servos
  • For motorized version a Dualsky XM3844EG-10 or similar motor, 80A ESC and 13×5″ folding propeller
  • 4S 4500 mAh battery for motorized version, a receiver battery pack for pure glider version

Product Description

The Letov LF-107 Luňák (English: Kite) is a Czechoslovak aerobatic glider designed in the late 1940s. The first flight of the prototype took place on June 25, 1948, and a second prototype flew in July. The prototype participated later in the same year in aerobatic competition in Grenchen, Switzerland, and in Ziar, Poland in 1949, where its good aerobatic and gliding characteristics drew considerable attention. With a designation VT-7, a simplified version of Luňák was used in the military for aerobatics training. The production ended in 1951  with a total number of 75 produced LF-107 gliders, only a handful of airworthy Luňáks have been preserved until now and it’s still a very popular veteran glider.

Julien Watier designed a 1/5 3D printable RC model of this very capable and distinguishable post-war glider. It’s suitable for experienced pilots and is a particularly strong glider in flight, even towed by a powerful tug plane. It is an aerobatic model: its mass allows for aggressive acrobatic flight at high speeds. Despite its weight, it is also capable of good performance in thermal flight. The four servo wing setup allows for safe short landings. The stall speed is relatively low, but watch out for the stall as it can be fatal. Don’t let the speed drop too low.


Wingspan: 2970 mm
All-up-weight: approx. 4,5 kg (standard PLA version)
Wing surface: 55,3 dm^2
Wing loading: 81 g/dm^2
Airfoil: SB95/11,5

First flight of the prototype (without flaps)

Hand launched motorized version

Assembly video



How it works

Download - Print - Assembly - Fly
  • 1
    Creating process of digital modelling

    Extensive hi-tech 3d structural reinforcement resulting in solid yet lightweight airframe thanks to additive 3Dprinting technology

  • 2
    Printing and testing

    Each plane has been thoroughly tested to find ideal shape and best possible inner structure

  • 3

    Choose your aircraft, download 3d files and print as many you need. Using your desktop 3Dprinter