In high school, I scoffed at the notion of taking shop class. Instead, I spent my time working on computers. That did alright by me until I decided to build a small jet engine, oh, ten years ago. It was then that I realized that perhaps I should not have scoffed so much.
By my reckoning, it will be approximately ten more years before I finish the aforementioned project, however today I reached a major milestone, thanks to the outstanding advice of my brother.
The plans call for a spun aluminum intake. At first, I didn't know what that meant. Once I discovered, I tried spinning some aluminum. Multiple times, as a matter of fact. The only consistent outcome was failure. Then Alan's sage advice rescued me.
Anneal the aluminum first. He was right. Along with that, I watched some very cool YouTube videos. I noticed that the "pros" don't spin very fast, and they use a lot of leverage.
I tried. It worked! When you look at the following pictures, you'll realize that I still need a lot of practice. That being said, I'm pretty happy with the "proof" of concept. With a bit more practice, slightly thicker sheet, and a new set of metal gears for my lathe...I might be on to something!
The pop can in the following photograph is simply to demonstrate scale. The raw material was a piece of flat aluminum sheet about 1/30th of an inch thick. The mandrill (form) is made from oak, and turned to shape.