After 8 weeks of my ONR-sponsored internship at Navair, I can happily report that the experience has actually yielded some engineering-pertinent educational insights. Although TCNJ’s engineering curriculum is respectably broad in it’s coverage you can never expect a college education, no matter how good or how expensive, to teach you every single thing you will need to know when you get a job. It’s impossible to predict every permutation of every career of every field. Working for the Navy, there are many unique aspects of the work performed here that simply wasn’t covered in school.These range from basics like nuances in using CAD software to considerations like what kind of steel to use. For any mechanical engineering student who still has an opportunity to augment their education, here are some things I would strongly recommend you either pay attention to or read up on, based on my experiences.
- CAD Modeling – In class, I would always take shortcuts in modeling, or omit certain obvious pieces. If you are creating a model that’s going to be used to build something in industry, you’re going to want to include every little detail. Even if it’s a .03″ deep recess where you’re going to place a sticker on the final product. If it’s going to require a machining operation, it ought to be there. Also, in making an assembly, include every last bolt. That way, everything is accounted for when you go to prototype the real thing.
- Drawings -Similar to above, if you are going to be making production level drawings, there are many knit-picky things that are required of you. Each company will have it’s own drawing format that you will be expected to follow, as well as formatting for drawing notes and such. Also, tolerancing is a big issue. If you chain together dimensions, you’re stacking tolerances. A square pattern of bolt holes, for example, should all be dimensioned from a common point, so that they remain square relative to each other. And one last thing.
- Mechanical Properties of Materials – At TCNJ, we spent a lot of time covering phase diagrams for alloys, as well as the microscopic structures of steel. While that’s a great foundation for knowledge, we never practically selected materials for applications based on their strength and such. For the first time of my engineering career, I had to select an appropriate alloy of steel based on simulated stresses that I had generated. I had no idea what grade of steel would be good. 1018, 4130, A36, 17-4… I was bewildered. Luckily, I’m just an intern and I can pick the brains of my coworkers.
- Material Science – Another big thing here at the Navy is corrosion resistance. It’s not a consideration I’ve ever had as a student, so when my search for parts on McMaster was suddenly restricted to stainless steel only, I was apalled. On top of that, I learned about the problems associated with dissimilar metals being in contact. These issues make material selection a huuuge pain, and is something you only overcome with experience. I have barely scratched the surface (pun) teaching myself about things like passivation, anodizing, and coatings that the Navy uses to mitigate these problems.
- Specs. – I still remember clearly Dr. Sepahpour telling us about how materials that meet a certain spec often cost more than their untested siblings. At the time, I dismissed that testing as garbage, and a waste of money. The way I saw it, an aluminum bar was an aluminum bar and variations between samples couldn’t be that bad. Why pay more? For a senior project, it might be understandable that a cheaper material would be chosen. But when you are building a piece of equipment that absolutely cannot fail, it becomes clearer why that extra level of audited certainty about a material’s properties is desired. The Navy references so many different specifications and guidelines it needs a search engine to sift through all the thousands of PDF-ed documents. Each spec details things like the tolerance of a bolt, to what shape that bolt’s threads are, to the permissible variation in angle of the corners of a square extrusion. There’s even one detailing quality control for Beef Stroganoff Meals-Ready-to-Eat, and how each ingredient must be “free of impurities” and have a “fine, pleasing taste”. Control freaks? Yes. But it’s what makes our equipment better than anyone else’s.
So that’s my brief rundown of some of the things I’ve personally gotten out of my internship. And I still have 2 more weeks to go. Hope someone, somewhere benefits from my rambling.