DOE for Manufacturing:

​

In order to test the importance of speed, feed, and depth when it comes to making cuts, we focused on the end result of each test cut in a binary manner. We judged each cut based on its ability to remove material, along with how the finish felt. We tested this by running our fingers over the burrs to find the sharp edges and by scratching the inside of the cuts with a screwdriver to determine how smooth the inside surface is. Since our cuts will be covered by our injection molded pieces, we decided that removing material is a more important feature than having a nice finish, Our Minitab analysis tells us that in order to remove material in the best way, the most important factor is speed. This was seen because speed had a P-value of 0.015, as seen on the Factorial Regression: Quality (Removing Material) page in our Minitab analysis. Also, the plot shown on the Factorial Plots for Quality (Removing Material) emphasizes this point. By having a faster speed, material is removed better. So, we decided to go with the fastest speed (4200 RPM), the biggest feed (15 in/min), and the deepest depth (0.02 in) in order to decrease the cost by a lot while also having a useful cut on our pieces.