An update on the current state, plus a few pictures.
I decided that I would run the Edwards E2M8 pump for several hours today. As prep, to make absolutely sure it would be OK, I oiled the motor bearings again, as well as the bearing in the center plate of the pump, and where the drive shaft enters the pump body. I used clean vacuum pump oil, as it is high quality non detergent oil, and by definition has a very low vapor pressure. I then powered it up, and pretty much let it run all day long. It is still running as I write this. The motor eventually got quite warm, but not to hot to touch, and the pump was quite a bit cooler than the motor, but also warm. The motor bearings were much cooler than the outer cylindrical shell of the motor housing.
Since I had another Varian 531 thermocouple, as well as another Varian 801 gauge, I put a KF16 cross on the pump, and connected both of the 531 TCs and 801 gauges to the pump. To my surprise I got VERY different readings from the second TC. Instead of reading ~200 microns, it showed the pressure at closer to 40 microns. I then switched which TC was connected to which gauge, and the readings on each gauge stayed pretty much the same. The gauge that had read 200 now read about 205 microns, and the gauge that had read 40 now read 35 microns. That was great news, as it means that the TCs themselves are in pretty close agreement. One reads about 5 microns higher than the other. Neither of the 801 gauges has been calibrated, or zeroed, since that requires that I get the pressure on the TC down to less than a micron, which I currently can't do. Clearly one of the gauges is off quite a lot. Which one I can't determine yet.
However, I'm feeling better about the pump, as I am hopeful that the lower reading is closer to the actual true pressure, than the higher one. I do have a capacitance manometer, that I may attempt to get up and running, if I can find or acquire the appropriate cable. I can use that to determine which of the TC readings is closer to the proper pressure (most likely they are both off at least slightly), but I am hopeful that the higher reading gauge will prove to be off by a lot.
Next I added a connection from my vacuum chamber to the Edwards pump and pumped down my chamber for the first time. It went down to about 50 microns per the lower reading gauge, pretty quickly. After an hour or so of pumping, it went down to the 35 micron to 40 micron range.
I valved off the pump to see if I had a leak, and the pressure in the chamber with the pump valved off was pretty stable. It rose about 10 microns or so in a minute. So not perfect, but I haven't done any glow cleaning yet, and the parts were not cleaned with solvent before I assembled them, so I am sure there is outgassing going on in the chamber. I did not make any effort to not leave fingerprints on or inside the chamber, hence my fingerprints are pretty much all over it, And I'm sure there is oil from my hands on some of the flanges and centering rings as well. In addition I live in the Seattle area, and so there is a lot of moisture in the air, and I am sure there is a lot of adsorbed water vapor all over every inch of the inside of that chamber.
I was happy with the fact that there were no major leaks. KF fittings really do work very well. They are easy to use and assemble, and they do the job. Plus you can reuse the centering rings as much as you please. Unlike copper conflat seals.
Here are some pictures of the chamber, TC gauges and vacuum pump setup. Note that the only useable 240V outlet I have in my house is in the laundry room, and I need to plug the pump into that. So you can probably surmise what is underneath the tablecloth.
Here is the Edwards E2M8
Here is the whole current setup
Here are closeups of the TC gauges showing the disparate readings. The first shot was just before closing off the vacuum pump from the chamber, the second shot is two minutes later after the pressure has risen, and the last shot is a few seconds after reopening the valve when the chamber has pumped down again.
Joe.