Sikorsky X-2
For inspiration, the Sikorsky X-2 developmental helicopter was used. This was in part due to the extra set of blades bringing motion into the toy, and part due to the preference of the engineers working on the project.
About
Toy Design Poject
Goal: Design a toy that moves, either driven by a motor, or by another motion applied to the toy.
Solution: A toy based off the X-2 was designed, with counter rotating blades and a tail rotor driven by motion in the wheels.
Tools
Inspiration
Sikorsky S-97
The second source of inspiration in the design was the S-97 Raider. This is the military variant of the X-2, and was used as a second design reference.
Design
Motion Design
All motions were to be driven by the wheels under the helicopter. The two sets of main rotors were to rotate in opposite directions, and the tail blade would also spin by the wheel power.
Exterior Design
The exterior design was modeled after the X-2 and S-97 originally, however bulges were added in the center section under the rotors to allow for the gears which were larger than initially expected.
Internal Design
The gearing was generated using Solid Edge. The design was to use bevel gears to transition power between the wheel and main rotors, and between the main rotors and the ground. The ratio is 2:1, to allow the main rotors a slower rotation compared to the tail rotor.
Final Product
The final product was assembled and airbrushed in a military camouflage style. The gearing was tight at first, and after lots of rolling, it loosened up and was became a smooth toy to roll around.
Nose View
The main rotors used concentric shafts in order to allow for the contra-rotating setup.
Side View
The gearing bulge can be seen under the main blades by the wheels.