II Design Process

Figure 1

We approached our design with the goal of having smooth motion without the use of gears. The process took multiple iterations. We used the values seen in the diagram above (Figure 1) as a reference so that we could ratio the lengths that we wanted to use to design all the linkages in the mechanism. We knew that the complete length of slider motion was 5.67 inches. We picked an initial value of 38 in the diagram as a start value. We assigned this value 1.8 inches, which we determined to be an ideal value for about half of the width of entire mechanism. We made the width of the mechanism slightly less than the length of motion of the slider so that there would be a gap between the shell and mechanism. This gap is essential for the mechanism being able to slide out of the shell without interference. Then, we ratioed the lengths of all the linkages, and designed them in SolidWorks.

Figure 2

Figure 3

Figure 4

As seen in the Figure 2 and 3 above, we started with a preliminary design how we wanted shell to work and how it would fit around the mechanism. Then we moved onto a more feasible design given the resources we had, which can be seen in Figure 4. The sketched design depicts both a front and side view of the shell and how the legs would fit inside. It also provides the dimensions of all the parts and allowed us to have a better preliminary visualization of how every would fit together. In the process of dimensioning all the parts in one sketch, we were able to decide what tolerance between each part should be in respect to each other so we would not run into any problems during the building phase. We based a lot of the dimensions around the sliders that were given to us because they were a fixed length, which meant that we were constrained to design around them.