ME360 Project #2: Gasket

The goal of this project was to learn some of the basic manufacturing techniques needed to manufacture various components in workshops such as BU's Engineering Product Innovation Center (EPIC) facility. Specifically, I was tasked with creating a gasket, a type of seal that holds two components together.

In order to create this gasket, we needed to used a caliper to accurately measure the dimensions of the identical components in inches that the gasket will hold in place. We were taught that using the lower jaws can measure the primary outside dimensions, the upper jaws can measure the inner diameter of a hole, and the depth rod that helps determine the height of certain objects. Using these instruments and their measurements, I produced a dimensioned sketch that serves as a basis for the creation of a CAD model via SolidWorks, which is shown below:

Figure 1: Paper sketch of my component-specific gasket. I labeled each utilized dimension for the SolidWorks CAD model.

Finally, using the SolidWorks model, I exposed myself to GibbsCAM software and G-code for the final manufacturing of the gasket on a CNC mill.

Figure 2: SolidWorks design of my component-specific gasket.

The picture below showcases my CAD model created for the gasket. It consists of four central holes to fit the rectangular and circular blocks with a fillet the components have, as well as two central holes to tighten the gasket to the components and four corner holes that were drill tapped so that #10-32 screws could easily fit through them. Additionally, there are 45 degree chamfers across all four edges of the gasket.

The application of a 1/200" tolerance was also placed into effect as I smart dimensioned each of the holes in the gasket. This tolerance will help the components fit more easily into the gasket and simultaneously make the gasket easily removable from the entire assembly.

After testing my modeled gasket with my component, I found that even with the tolerances accounted for my modeled two central pins was a little too small as compared to the actual distance on the block, which I re-calculated to be 2.253 in as shown in Figure 1. For this reason, despite the fact that I am able to fit my gasket into the component, it buckles and bends downward by a slight degree. For this reason, applying too much force when inserting or removing the gasket from the component would most likely cause it to snap.

Figure 3: CNC-milled design of my component-specific gasket.

Figure 4: Attempted insertion of gasket into the component. As described above, there is a slight downward buckle due to the slight miscalculation I had when I modeled my gasket as compared to the actual value.

From this project, I was able to see first-hand the possibility of how even the smallest margins of error can affect the overall result of component assembly, whether it was because of slight misreads from applying too much or too little force on the caliper's jaws or because the tolerance was too small or big. However, even with this in mind, exposing myself to the manufacturing process of modeling and sending said model to CNC machines by working through GibbsCAM proved to be a fruitful experience.