Original Year
# of pieces
Aircraft:  Helicopters
Rotating main and tail rotor
Other Views

8825 Night Chopper

iso revolve
Click the image to download the LDraw file of this model.
Model by Benjamin Wendl

This small helicopter, released in 1990, was the smallest to date at the time.  It features rotating main and tail rotors.  The canopy is constructed from liftarms and links.  The liftarms lock at 90 degree angles, while the links are pinned.

This is the only Technic set released this year which does not have wheels, and remains one of the very few such to this day.

This particular little model looks vaguely like a Robinson R22.


The rotors' rotation is driven by an input crank on the left side.  This crank drives a set of 8 and 24 tooth gears.  The 8 tooth gear drives the main rotor.  The 24 tooth crown gear meshes with a second 8 tooth spur which runs back to a set of 14 tooth bevel gears on the tail rotor.  Both main and tail rotors turn at the same rate, with a ratio of 3:1 with respect to the input crank

The main and tail rotors each have 2 blades and use the specialized 2 blade rotor part for this purpose.

crank    rotor
 Click for an animation of the rotor in motion.
The landing skids are constructed from beams and  supported by liftarms.

Other Views

Side View
side view
Top View
top view
Front View
front view
Computer Render

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