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This resulted in three potentially viable linkage configurations that would maximize spring displacement. After careful consideration, we opted to proceed with the rightmost leftmost design.
** REV2-2** **REV2-4** **REV2-3**
During the design process, we realized that we were not considering the bearing ratio of our sliding link and were risking experiencing severe binding in our system. We adjusted the design such that we would have a bearing ratio of 1.5, yielding a link that was significantly larger in size than before. The position of the bearings was determined based off the idea of minimizing the moment of the lower links without making the assembly bottom out before full input link actuation. We also specified a location for our motor mount at the center of the link, a decision that would be changed later on in order to better accommodate our final cam design.
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We aimed for a cam design capable of inducing a transmission angle as close to 180 degrees as possible while swiftly retracting. Initially, we used a geometry based on the linear motion of the joint, crafted using Solidworks. However, this approach did not work. Instead, we adopted a more improvisational method, shrinking the geometry slightly, adjusting for the final length, and progressively increasing the curvature radius in the part file. Iterating through this process, we ensured constant contact in the assembly, refining the design until achieving a promising result, despite the unusual motion graph of the joint. Ultimately, we settled on a design and 3D printed approximately three iterations of the cam. Press fitting secured it to the motor during the final stages of system assembly.
ADD A PICTURE OF CAM, I CURRENTLY DONT HAVE ACCESS TO SOLIDWORKS
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Rails
The linear rail system was designed to constrain our mechanism to 1DOF. We used two 3-foot long 8mm rods from McMaster-Carr as our rails, initially planning to cut them down to a realistic size for our mechanism's jump height before deeming that decision unnecessary. In order to successfully ground our assembly, we needed to construct a sturdy frame that could hold our rails parallel to one another. Initially, our team was planning on building the rail framing assembly out of 1/4-inch laser-cut wood, but we were able to get access to 80/20 aluminum extrusion from the lab of one of our group members. Therefore, we were able to build a significantly studier frame that would be able to easily accommodate the full length of the rails. We did continue to use a wood base, as it allowed for a smooth, uninterrupted surface for the mechanism to jump on; this was manually cut and fit around the frame. The rails were attached to the frame using 3D-printed feet screwed onto the wood base and frame top. The rails were spaced evenly apart such that they lined up with the mounting positions on the mechanism and stayed in line with the 80/20.
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