Cheap vacuum pump for home physics experiments

As documented earlier, I made one of those CRT-in-a-winebottle things. I used a cheap 2-stage mechanical vacuum pump for it. Well, it was so good that my boss wanted to use it as a science demo at some dinners he gives, so it’s been permanently transferred to work. So I need a new pump, and a new chamber!

I ordered another of the same cheapo pumps, but this time I got a more precise vacuum gauge too. As it turned out, this pump, which was rated to ~2 microns, only got down to 750 microns! Not good enough for 1800s physics experiments. So I found these VIOT pumps. They look great and just have that reputable feel. My VPD5 is in the mail, rated to 15 microns. We shall see! UPDATE: Oh yeah, VPD5 is EPIC! It got down to 2 microns on my gauge. Very nice.

For a chamber, I thought I’d try a peanut butter jar (see video). I used a hole saw to cut into it and mounted a NPT/quick-disconnect coupler to it with a rubber washer. I actually have no idea if the quick-disconnect things can hold any kind of vacuum (I sort of doubt it) but I’ll let you know. I think compression fittings will be much more suitable for these mid-vacuum levels. Not quite swagelock but whatever.

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