The Machine Shop

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:

Flip Stage 1

Flip Stage 2

Flip Stage 3

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.

CNC Action Shot

Here’s a cleaner version so you can see what the CNC did. Isn’t it pretty?

Somewhat Symmetric

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.

Angled Part

Finally, if you’re interested, here’s the entire process of what I did to make the part:

The Flip Stage Process

  1. I got a stock bronze cylinder.
  2. 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.
  3. 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.
  4. A drilled a few holes on one end using the mill.
  5. 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.
  6. I flipped it upside down and made a few more holes with a CNC.
  7. I used the CNC to remove material around a few rectangles on the bottom.
  8. 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.
  9. I cut away a large piece of the box to leave an “L” shape.
  10. I milled away part of one end.
  11. It might be hard to see in this picture, but I angled the sides. This necessitated turning the whole mill head by fifty degrees.
  12. I made another small counterbore on the other side of the protruding cylinder.