Machine Shop Experience

Introduction

California Polytechnic University - San Luis Obispo (Cal Poly SLO) has a set of three manufacturing classes that all Mechanical Engineers have to take to graduate. They are Machining (Milling, Lathing, etc.), Welding, and Casting. I will go over the experiences gained in these three classes.

Machining

Lathe

I have the most machining experience on a manual lathe. I used it during my senior project course and used it to fix things around the house. Here is one project I worked on a lathe to complete. I fixed my futon couch.

When I moved into my rental in San Luis Obispo, the futon couch was already broken. One of the previous tenants had jumped on it and a critical piece snapped. It was the circular part that held the bed to the frame.

I was taking the lathe course at this time, and I asked my teacher if I could make a replacement part out of aluminum. This would not only fix the broken plastic piece, but also would be stronger to prevent it from breaking again. The wooden frame would break before this piece does. For this project, I used a chamfer tool, standard carbide tools to face and turn the aluminum cylinder, a drill bit, a tap, and calipers to measure the part that broke.

I also made may small trinkets to practice different cuts with a lathe. The other big project I had on a lathe was for my senior project that was under an NDA so I cannot show it here. I had to use a square lathe with brass to complete that project. The materials I have lathed up to this point are Acetal, pvc, aluminum, brass, and steel.

CNC Mill

The class was full of little trinket projects. We were not in charge of coding the machines for these projects specifically, but we did learn how CNC code works alon.g with how to upkeep the machines. We learned the emergency shutoff as well to not break the machines

All of the trinkets were made of aluminum. Here is one example of what I was able to make in the lab. They are full of small details. I also used a manual mill on my senior design project.

Casting

The casting class was very similar to the CNC classes; we made many trinkets. I did however design my own mold for a Father’s day gift for my dad. This is what I was able to make.

The final project for the milling class was a culmination of all of the above classes, to build a working air-motor. The pieces are first made in the casting class. The parts are then taken to the machining class where they are milled and lathed down to a tighter tolerance. The goal is for the cylinder to be air tight, so they have to fit well together. Air is blown into the top of the cylinder and it pushed the piston down, causing the shaft to rotate with a flywheel to keep the momentum.

Welding

The welding class was full of practice welds. We never made a design here, we generally stuck two steel plates in different configurations and welded them together. The joint types I practiced were butt, tee, corner, lap and edge using TIG and MIG processes.