Fabrication and Assembly

After our initial prototype was made, we found that there were some minor issues and adjustments that needed to be made. First off, we realized that press fitting our 2 ternary links to a regular, cylindrical shaft would not be enough to align them in tandem perfectly across all movements of the mechanism, so we decided to update our ternary shaft to be a D-shaft instead.

• Insert image of the D shaft CAD

In addition, we decided to add shaft collars to onto the output shaft and the ternary shaft to keep all the pieces in line during movement, and replaced our hand crank with a 12V DC motor.

Finally, we increased the thicknesses of all our links to improve overall link strength and added a modular end effector to the end of our modified pink link. We decided on adding this end effector for our final design as it allowed for flexibility to adjust how we wanted our ball to launch on contact. Additionally, we adjusted the shape and size of our top base plate for increased transparency and design compaction, and added a bottom base plate for overall rigidity, adjusting the shape of our standoffs accordingly. The final CAD with all of our changes is seen below:

• Insert Images of entire system

We manufactured the D-shaft by hand with a manual mill according to the specified dimensions on our CAD, though with any process nothing is perfect. The two ends were different from the dimensions in the CAD, 

For the links, we recut them 

Hardware

The hardware components utilized in this design are a 12V DC motor, a power supply, an L298N motor controller, an Arduino, and a potentiometer. 22 AWG jumper wires were used to connect these components together to form the circuit below. Note that the L293D acts as a placeholder for the L298N.

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Figure 2. Circuit Diagram

Software

The team integrated the hardware components into the final prototype using an Arduino. The code involved reading the analog signal from the potentiometer in order to adjust the PWM signal to control the motor. The final code can be seen below.

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Figure 3. Arduino Code