UMFlint - Physics

Home Products Services Links Contact Goofy Stuff Silly Pics Amys Gourds Bronze Boar Cooler HCEA Railroad UofM - Flint Physics More Physics Pumpkinfest Old Work Pics	This project is the vacuum chamber, used in the arc vapor deposition process. It is used to create buckyballs and nanotubes. We want to be able to lift the entire vacuum chamber into an atmosphere isolation chamber (or vented fixture) before opening, so the weight is limited to about 30 pounds for the project. Due to the lack of availability of lightweight vacuum chambers, we decided to make our own chamber from scratch. We started with flat stock aluminum, a length of tube stock aluminum, and copper. Click on pictures to enlarge. This is the underside of the top flange. It is milled to fit the aluminum tube, which will make up the body of the chamber. The twelve threaded holes are separated by 30 degrees. It's likely only six bolts will be required to keep the top cover on and a decent vacuum within the chamber, but there are twelve bolt holes there if needed. This is the bottom plate of the chamber. It will not be removable. The holes match the top cover and top flange, which can be used to mount the chamber in the laboratory or bolted together for final welding. The chamber will be submerged in a tank of water during the creation of the nanotubes, because of the heat generated during the vapor deposition process. Much consideration is made between having a small enough chamber to lift and carry, yet large enough to dissipate the heat. After the top flange was completed, it was remounted on the lathe and used as a guide to clean up the top cover and bottom plate. Because the lathe chuck didn't have enough clearance to bolt the top and bottom covers to the flange, we made four spacers out of brass to hold them with precision. This is the copper plate which will secure the copper sample mount. We used copper for its thermal and electrical conductivity characteristics. The sample mount and and mounting plate will be secured with brass bolts. The three holes in the center are separated by 120 degrees and will mount to the 2 inch round copper sample holder. The holes in the outer ring are separated by 60 degrees and will mount this copper plate to the bottom plate of the chamber. Here the bottom copper plate is upside down in the chamber. This was just to see what it looks like. Here's the main body of the chamber being finished on the lathe. The 2 inch copper round stock is what we made the sample holder out of. Also, there was a design change to add a window. The aluminum tube stock on the left is going to be added for the body of the viewport. We also have to make a small flange to secure to the window plate. The flange to hold the window plate was too small to work with on our vertical mill. So we had to make some new tooling. We made a mount to support a four jaw chuck to use in the vertical mill. I needed to make a new chuck key to be able to adjust the jaws. I used a collet block to secure 1/2 inch round stock and milled it to fit the chuck. Dan used a surface grinder to shave keys we made onto the bottom of the new chuck mount, so they fit into the rotary table. Bridgeport rotary tables have a tapered slot, so these keys had to be finagled. Here is the completed mount with the four jaw chuck. I was then able to begin work on the window flange. On a recent return visit to the physics lab, I found a student using the chamber. It was modified, but it was nice to see the core strucure still in use! -Rob Home

This project is the vacuum chamber, used in the arc vapor deposition process. It is used to create buckyballs and nanotubes.

We want to be able to lift the entire vacuum chamber into an atmosphere isolation chamber (or vented fixture) before opening, so the weight is limited to about 30 pounds for the project. Due to the lack of availability of lightweight vacuum chambers, we decided to make our own chamber from scratch. We started with flat stock aluminum, a length of tube stock aluminum, and copper.

Click on pictures to enlarge.

This is the underside of the top flange. It is milled to fit the aluminum tube, which will make up the body of the chamber. The twelve threaded holes are separated by 30 degrees. It's likely only six bolts will be required to keep the top cover on and a decent vacuum within the chamber, but there are twelve bolt holes there if needed.

This is the bottom plate of the chamber. It will not be removable. The holes match the top cover and top flange, which can be used to mount the chamber in the laboratory or bolted together for final welding. The chamber will be submerged in a tank of water during the creation of the nanotubes, because of the heat generated during the vapor deposition process. Much consideration is made between having a small enough chamber to lift and carry, yet large enough to dissipate the heat.

After the top flange was completed, it was remounted on the lathe and used as a guide to clean up the top cover and bottom plate.

Because the lathe chuck didn't have enough clearance to bolt the top and bottom covers to the flange, we made four spacers out of brass to hold them with precision.

This is the copper plate which will secure the copper sample mount. We used copper for its thermal and electrical conductivity characteristics. The sample mount and and mounting plate will be secured with brass bolts.

The three holes in the center are separated by 120 degrees and will mount to the 2 inch round copper sample holder. The holes in the outer ring are separated by 60 degrees and will mount this copper plate to the bottom plate of the chamber.

Here the bottom copper plate is upside down in the chamber. This was just to see what it looks like.

Here's the main body of the chamber being finished on the lathe.

The 2 inch copper round stock is what we made the sample holder out of. Also, there was a design change to add a window. The aluminum tube stock on the left is going to be added for the body of the viewport. We also have to make a small flange to secure to the window plate. The flange to hold the window plate was too small to work with on our vertical mill. So we had to make some new tooling.

We made a mount to support a four jaw chuck to use in the vertical mill. I needed to make a new chuck key to be able to adjust the jaws. I used a collet block to secure 1/2 inch round stock and milled it to fit the chuck.

Dan used a surface grinder to shave keys we made onto the bottom of the new chuck mount, so they fit into the rotary table. Bridgeport rotary tables have a tapered slot, so these keys had to be finagled.

Here is the completed mount with the four jaw chuck.

I was then able to begin work on the window flange.

On a recent return visit to the physics lab, I found a student using the chamber. It was modified, but it was nice to see the core strucure still in use! -Rob

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