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8855 Prop Plane
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 Click the image to download the LDraw file of this model. Model by Koyan |
Features |
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Engine
This single cylinder engine is not particularly realistic, but is the
only one which would adequately fit in the space available. The
cylinder actually faces down instead of up which would lead to
significant amounts of oil being burned, but no worse than many 1940's
era radial engines.The unique 3 blade propeller passes through an integral 4L beam and into a 24 tooth spur gear with an offset axle hole. The offset axle holes of the 24 tooth gears are used to make a crankshaft. Connectors placed end to end and clocked 90 degrees form a rod which connects to a specialized 2x2 square piston. The "cylinder" is actually square. |
 Click for an animation of the engine in motion. |
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Pilot Controls
To control the rotation around the axes of 3-dimensional Euclidean
space, a real airplane uses a control column (or stick) and rudder
pedals. Movement of the stick fore and aft controls pitch, and
side to side controls roll. Aft stick is a nose up command, and
right stick is a clockwise roll. Rudder pedals control yaw.
This model accurately represents the function of the stick, including
moving in the right directions. There are no rudder pedals.The only inaccuracy is that there should be a separate column for pilot and copilot. Aircraft which use side sticks typically have them at the outboard side, not in the center. The second photo shows the interconnected mechanism which drives the ailerons and elevators. More about this below. |
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Ailerons
The primary control surfaces of aircraft which control roll are
ailerons. These panels on the trailing edge of wings move in
opposite directions (one moves up while the other moves down).
Large aircraft may have both inboard and outboard ailerons, and even
more roll control may be obtained through the use of flight spoilers.In this model, left and right motion of the control stick rotates a longitudinal axle. This axle drives a triplet of 16 tooth spur gears. The final gear rotates a 3 blade rotor piece. A pair of the new tie rods attach via ball joints to crank arms on the wings. These crank arms turns axles which run outboard to the ailerons. The direction of rotation is reversed via a pair of 8 tooth gears to make the aileron motion accurate with respect to the control stick. |
 Click for an animation of the ailerons in motion. |
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Elevator
The primary control surfaces of aircraft which control pitch are
elevators. These are typically panels on the trailing edge of the
horizontal stabilizer but, in this case, the entire horizontal
stabilizer pivots. This is sometimes called a "stabilator".
The two sides move in tandem, always in the same direction with respect
to each other.In this model, forward and aft motion of the control stick pushes and pulls one of the new tie rods via ball joints. The tie rod pushes or pulls an axle which rotates a crank. The crank reverses the direction of motion and then pushes or pulls a long link which goes all the way to the tail. The stabilizer pivots around a pair of pins. |
 Click for an animation of the elevators in motion. |
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Skids
This aircraft has both floats and landing gear so it can be operated
from either land or water. The floats are supported by an
elaborate truss system constructed from toothed connectors as seen in
the photo. The 4 small tires are hidden within the floats. |
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Other Views |
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Side View |
Top View |
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Front View
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Back View
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Computer Render |
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