DIY vacuum chuck questions

[Neal DaMommio]

I just used some air hose I had laying around.

As far as the 3/8 all thread of course with some lathes you don't need the to use all thread because the spindle is airtight. If you do need it there are kits that come with the tube and bearing already installed for about 60 bucks that would take care of that issue. What type of lathe do you have?

[Brice Rogers]

Pete,
When you get your bearing, make sure that it is a SEALED bearing and then do a test to determine whether it is a contact type sealed bearing or a non-contact type. You want the contact type because they don't leak. I bought some otherwise good "sealed" bearings from VXB and (although nothing wrong with the bearings) they leaked like a sieve. They looked like and were called "sealed" bearings but they were the non-contact type. I could only draw 5" of vacuum because there was a 0.007" gap all around the inner race. I tried pushing grease into the gap and it readily sucked it into the bearing and would temporarily increase the vacuum to perhaps 15". I finally threw in the towel and bought a pair of bearings that were mounted to a hub and had a 16" poly "tail" for around $25. They work well. The frugalVC guy supplies the poly tubing style rather than a 3/8" lamp rod style. He says that it works as well and it probably does.

For the tubing I first tried some clear soft tubing from Home Despot or Lowes. It was too soft and would flatten under vacuum. Then I got some hard poly tubing that is kind of a milky white. It works well. I ran 3/8" (ID) poly from the pump, filter, etc. to the 16" poly tail (frugalVC source). The tail is 3/8" OD and 1/4" ID and it seems to fit perfectly into 3/8" (ID) tubing.

[Pete Staehling]

Thanks again guys. Since I got a do over when they were out of stock on the pump that I ordered, I just ordered the super frugal kit. So I should have good functional stuff coming.