Over the course of ten weeks, my engineering design class designed and built a thermoforming machine from scratch. Thermoforming is a very useful process where a sheet of plastic is heated and draped over a mold, then the air is vacuumed out of the plastic. Once the plastic cools, an outer mold is released and can be used for many machining processes.
I was selected to be one of six project managers, each in charge of nine other students. My group was the mechanism group, and I was responsible for coordinating with the plastic holder, heating element, vacuum plate, vacuum system, and frame groups. The mechanism’s role is to move the plastic holder between the heating element and the vacuum plate. I delegated tasks, set schedules, incorporated the ideas of team members, budgeted, and ordered materials, along with spending my fair amount of time in the machine shop.
Our design consisted of two hinged lever arms to provide mechanical advantage, and shafts with linear bearings to provide vertical motion. We overcame many issues during the final week of testing, including a singularity in our lever arms, excessive racking, and magnets strong enough to hold the plastic holder at the top of its range. We were able to move the lower pivot point for our lever arms, realigned our bearings and installed guiding springs, and created a backup hook mechanism to replace the magnets.