Mechanism Dissection:
Our prototype's mechanisms can be classified under two sections with 3 total working components, which are listed below:
- Walking-Beam Mechanism and Chute Slider
- Lazy Susan Reloader
Powered by a 12V DC motor, the walking beam serves as the driving mechanism of our assembly. This mechanism has a D-shaped motion that exerts a cocking and releasing motion on the chute slider (which is placed on a linear shaft and is tensed with a rubber band) that is very similar in functionality to a slingshot. As the slider is being pushed back, it will hit the lower fan of the Lazy Susan, which in turn rotates the top fan and pushes a marble into the cutout that makes it fall into the chute slider. As the linear portion of the "D" motion ends, the pushing arm (attachment to the walking beam) will no longer be in contact with the slider which will release the tension in the rubber band and will send the slider forward at a fast speed. Lastly, the linear shaft mounts will act as a stopper and the inertia from this launches the ball forward.
Design Considerations and Goals:
- Strong links to withstand high tension
- Adjustable z-axis position for a simpler assembly
- Low friction for better performance
- Reduced weight to avoid cantilevering the walking beam
- Optimize link lengths to find a satisfactory stroke length and obtain linear motion
The considerations above are crucial for a proper build of our design. The mechanism is exposed to a high tensile load from the rubber band, so having a good structure and strong build for our links is very important. Assembly