The top picture shows the CAD model of the contact cup. The bottom picture shows the physical model machined out of a solid piece of acrylic. It is important to note the difference between the two smaller pieces that are inserted into the larger body in the main assembly. In the CAD model it can be seen that this part is designed to be of a uniform diameter. This is to allow enough room between the two walls inside of the chamber so that there is no interference once the secondary tubing is inserted into the side of the cup. When it came to machining this part of the assembly, problems were experienced during the process of parting from the stock acrylic rod. The very small cross section of the part meant that the acrylic would crack before it would cut, causing a jagged edge on the part that left it unuseable. This was remedied temporarily by increasing the diameter at the parting end of the rod to prevent cracking while leaving the other end unaltered to ensure that the tubing could still fit over the rod. While this larger diameter increases the possibility of interference between the secondary tubing and the inner wall, the team determined that it was suitable for the alpha prototype. However, this dimension being important for the purposes of the beta prototype, the team plans to either experiment with different materials (i.e. metals) that are less brittle than acrylic or utilize a smaller parting tool with a finer edge during the machining process.