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Features
Flight controls:- ailerons (from cockpit and HOG)
- rudder (from HOG)
- elevator (from cockpit and HOG)
- flaps (from cockpit)
Other:
- flat V4 engine
- Propeller pitch control (from cockpit)
- retracting landing gears (with knob on the bottom of the plane)
- nose gear with drag steering
- manual propeller drive with ratchet (on the left side of the plane)
- canopy door and engine cover opens
Play features and operation:
There are two main groups of commands: cockpit and hand-of-God. The cockpit (apart from the working dual joysticks) has the controls that are less frequently used: propeller pitch and flaps control. The HOG area has the main operational features: ailerons, rudder and elevators.
The color vomit in the chassis is intentional, there is also some level of function coloring inside but I didn't force it too much.
Design process and challenges
There were too many challenges to describe them all.Landing gears
Connecting the front gear with the main gears required redesign of the whole middle part of the chassis which was hard enough to design for the first iteration, but in the end, the final solution fits very nicely into the chassis. Just like the whole model was designed around the landing gear mechanism. After so mush struggling with the whole thing in the first iteration of the chassis, I was lucky in the second iteration because despite of the slightly different linkages for the main and front gears, the range of operating was the same and also the mechanism could be perfectly synchronized. So front and main gears snap into deployed position in the same time resulting in a very stable stance.
Ailerons
Many requirements made refining this feature very hard:
- proper range in during both up and down movement - I preferred a differential solution: bigger movement upwards than downwards
- proper centered position - ailerons point slightly downwards to follow the wing profile
- no jerkiness - at least the center position has to be easily set with the joystick
- space constrains by the wing structure
- only legal solutions - no twisting of axles, etc.
Tail
The fuselage towards the tail was one of the toughest part of the design. It has to be relatively thin, stiff but also has to contain two linkages to the rudder and elevators. I decided to solve it with an “off-system” truss because no Pythagorean triangles fit the shape without being in way of the linkages. Also a 4-stud high straight chassis seemed to be too thick, especially because some linkages have to go below the lower beam, plus it has to be reinforced which would increase the weight, etc. But this off-system choice introduced other issues. I don’t know how many iteration went into the design because apart from the aforementioned requirements, there are two very important ones which I failed to realize in earlier iterations: the tail plane has to be parallel with the pulling vector/centreline (I don’t know the proper term) and also the centreline of the fuselage should lie on the centreline of the whole plane which is the same as the axis of the propeller. In the final version I had to sacrifice a bit of the cleanness of the linkages I already had. This also introduced slight rubbing between the two linkages, so I added return-to-center mechanism to the rudder. I selected the rudder because it’s more obvious than the elevator if it’s off-center, and also the elevator is more likely to be played with than the rudder.
Bodywork
This, again, was very challenging but with a big ”innovation”, I managed to come up with a satisfying design. The innovation is the color stripe slightly above the centreline. As it divides the general appearance into “up” and “down” half, it effectively hides panel flow errors and gaps. Black color also hides panel flow errors which is especially important at the back of the canopy door with the hand-of-God joystick.
The design process was the toughest I experienced so far, the model was actually built for a contest hosted by Eurobricks (visit information topic) but I couldn't finish it in time.
Anyway, I'm satisfied with the model, it was my first ever airplane model and I'm not even into airplanes.
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