In our initial prototype, we focused on designing one quick release mechanism to get a better sense of the motion. We only used the laser cutter as it was quick to manufacture. We had to perform tolerance tests to check that the bearings would be able to press fit securely. We tested a 10.6mm, 10.8mm, and 11mm hole. For our initial prototype, we used 10.8mm for our press fits, as we could press them in with our hands. For the final prototype, we used 10.6mm and a vice to press them in.
A video of this initial prototype is shown below:
VIDEO
From this prototype, we were able to get a better understanding of the various locations of play in our system. We wanted to make our final prototype more robust, by having everything press fit to reduce play. We also wanted to 3d print the two halves of the gripper to ensure that those components were fully rigid. With these 3d printed grippers, we could also design the gripper to take the shape of the water bottle lid, which would keep the bottle in line with the gripper. Dr. Yuke Zhu also gave us feedback that our mechanism was a little too large. We decided we could scale down the overall design, and remove the part of the slot that was unused.
We had to perform tolerance tests to ensure that the holes could press fit 5mm wooden dowels in. The part we used for tolerance testing is shown below. It has a 4.8mm, 5.0mm, and 5.2mm diameter hole, and was printed vertically to match the orientation our final part would be printed at.
From this test, we found that the 5.2mm diameter hole size would allow for the wooden dowels to be press fitted in.
The 3d printed components in our final design are shown below.
