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Part of the design process for our final design was finding a way to assemble the launcher for the court. First, we needed to figure out how we wanted to attach the motor to link 2. Shown in Figure 6 is the motor mount we 3D printed. The motor mount mount allows the motor driver to be screwed directly into the mount using heat inserts on the side face. Initially, we wanted to screw the face of the motor directly onto the motor mount, however, we quickly realized that it wasn't feasible as it wouldn't allow the shaft of the motor to reach the opposite side of the ground link. We then went through a few different iterations of press-fits to securely mount the ground link of the launcher to the basketball court. Below in Figure 7 are the iterations of press-fit hole sizes that we used to determine the best mounting. Additionally, we had to iterate on the design for the ball holder to both hold the ball as snugly as possible so that it can launch properly and so that when it is attached to the end of link 4, the ball holder is not cantilevered and adding more stress to the joint than necessary. In Figure 9, the two iterations of the ball holder design are shown. The design we ended up with attaches the holder to the end of link 4 by being bolted in on either side of the link rather than to one side of the link. Another design aspect that we iterated on before settling on the final dimensions, was the fitting for the D-shaft of the motor. In Figure 10, the different hole sizes that were tested for press-fitting are shown. A proper press fit here was crucial as because if the D-shaft had any wiggle room it would cause the links to not rotate as calculated, making it very difficult to get an accurate shot trajectory. When testing we found that the 3D-printed basketball balls often bounced out of the 3D-printed hoop. To solve this issue we attached velcro strips to reduce some of the kinetic energy on impact helping the balls stay within the hoop. The strips also helped ensure that the locations would be consistently placed with various users so we decided to keep them in the final design, rather than needing to know the lines on a basketball court.
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