Using the machine shop is one of the best things about working in an experimental physics group. I love the machine shop! Words probably cannot describe its awesomeness, but I’ll try anyway: grinding tool bits is like meditating. Using the lathe to peel away an oxidized surface—thereby revealing the shining fresh metal underneath—is like magic. Everything is sharp, weighs alot, and/or moves fast. And successfully finishing a complicated part brings supreme satisfaction.
Speaking of that—I just finished a complicated part! It’s a phosphor bronze flip stage for a new ARPES sample manipulator. (I realize that doesn’t mean anything to most people, but I’m including its name for completeness.) It took me a few weeks to complete. (And I couldn’t have done it without a lot of help from Nate, Supreme Machinist and Overlord of the Graduate Research Shop.) I’m really excited and want everyone to see it! So here it is:
The colorful areas are regions of oxidized bronze. I didn’t thoroughly clean the oil off my part at one point, and after sitting around for a few days, the surface started to oxidize. The lines on the bottom are marks from the CNC that I used to mill out the protruding rectangles. The circular scratches around the central hole are from a Brillo pad.
Here are a few shots from the machining process. The first shows the CNC in action, milling away the bottom of my part. There’s a long bronze chip stuck to the cutter, spinning around.
Here’s a cleaner version so you can see what the CNC did. Isn’t it pretty?
This shows my method for holding the part when it got too thin: I had to bolt it to an aluminum block. In this picture, I have used a thirty-degree parallel to hold the part on an angle.
Finally, if you’re interested, here’s the entire process of what I did to make the part:
- I got a stock bronze cylinder.
- It was too big, so I had to cut down its length. First I used a band saw, then I faced off the uneven cuts with a lathe to make sure the ends of the cylinder were parallel.
- I then made it into a box. I made rough cuts with a band saw, then used a mill to ensure all the faces were parallel/perpendicular to each other.
- A drilled a few holes on one end using the mill.
- I held the part in a four-jaw chuck on a lathe and lined up the largest hole with the lathe’s rotation axis. Then I turned down the box into a cylinder.
- I flipped it upside down and made a few more holes with a CNC.
- I used the CNC to remove material around a few rectangles on the bottom.
- It might be hard to see in this picture, but I used the CNC to make a small counterbore at the end of the protruding cylinder.
- I cut away a large piece of the box to leave an “L” shape.
- I milled away part of one end.
- It might be hard to see in this picture, but I angled the sides. This necessitated turning the whole mill head by fifty degrees.
- I made another small counterbore on the other side of the protruding cylinder.