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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. The design also includes through slots to allow zip ties to be attached to the motor for extra security.  We 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. Once we found a good press fit we attached the ground link to the base plate using wood glue, shown in Figure 8 below, to ensure it stayed in stay in place with the vibrations of the robot. 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 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. After all the dimensions were settled on we were finally able to laser cut our links out of acrylic and press our 8 mm bearings into the links, the hole sizes for this press fit of were found in the initial prototype phase. We then cut down our 8 mm shaft into two 1-inch pieces and one 1.5-inch piece, using the machine shop. After we got our desired lengths of the shaft we filed them down and pressed them into our bearings. To ensure there was no play between the linkages and the shafters we 3D printed lock collars, shown in Figure 11 below. When attaching the lock collars we used clamps that were placed around the linkages to help create a tight fit and help minimize any play that would occur. After the linkages were assembled we attached them to the ground link and screwed in the motor and motor mount. After this process was down we attached our 2-inch 3D printed feet to elevate the court off the ground and allow the electronics to be mounted to the bottom. After all the assembly was done we were finally able to test our code. Initially, we just wanted to have the engraved sketch of the basketball court be how to mark the locations of the basketball hoop, i.e. close three, half court, far three, full court shots.  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. After getting all the right rpm of the motors and timing right on the code we decided to make our robot more aesthetic. The first step in this process was adding a button cover, shown in Figure 12 below, which hides the breadboard while easily guiding the user on how to make an accurate shot. We then laser cut jerseys with our team members' names, shown in Figure 13 below, which were attached to 3D-printed game pieces to stand on the basketball court like a 5 person baseball team, with the 5th member being our robot. 


Figure 5: Final Linkage Design with End Effector and Motor Setup

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Figure 10: Iteration of press-fit for D-shaft of motor

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Figure 11: Lock Collars

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Figure 12: Cover for breadboard to ease user input

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Figure 13: Basketball Jerseys