LV Vacuum pumps

[dubliner]

We have a trade school here & it seems there are more than a few AC vac pumps for sale on CL, brands like Robinaire, Gast, JB etc. Are these the same vac pumps that are used on hold down pods & hoist pods?

[billp]

Nev,
Yes, these are some of the major brand names. You can usually look up specifications, and get replacement parts for most units made by these people easily on the web.
They don't draw much power, and have infinite uses in any shop, so get the units with the best CFM and suction stats ( at least 22 inches of mercury if you want to do a lot with these units).
Remember since you're moving less CFM you need to offset the potential "leakage" by having as much suction as possible.
Smaller (1/4 hp) pumps work well for pods, and designated jigs. Larger pumps let you run multiple vacuum lines, daisy chain pods, and then use the same rig for assembly vacuum clamping, vacuum bagging, etc. Vacuum pumps seem to last a long time so get one that will get you where you ultimately want to go...

[cnc_works]

The auto AC vac pumps I have used seem to put an oil mist into the air. By keeping your eyes open on Craigslist or ebay or anyother local sources, you should be able to buy a good carbon vane pump. I found a great 3/4hp commercial continuous duty one that I traded a $60 sander for and a 2hp heavy duty one for $300 at a local surplus equipment store. I use the 3/4hp for most of my no-vac-loss jigs and it is more than sufficient.

Donn

[henrik_o]

We are very happy with our regenerative Siemens ELMO pump (it was free, after all...), but we're definetly looking for something bigger and better.

I'm fairly certain it's going to be a roots blower, lots of blow for the buck, so to speak, and we can put it into a sound insulated room.

However, I've also looked at those small compressed air driven units from Norgren which go for about $15-20 (if bought in quantity). True, many of them would demand a lot of cfm from the compressor initially, but we do have a large compressor. Also, with Norgrens "smart vacuum" (or whatever it's called) control tech it may suddenly be a viable option.

I really wish I knew vacuum tech and theory, I can say that much for sure.

[knight_toolworks]

you want to get a pump that moisture will not mess it up. your sucking a lot of air and all that moisture is hard on oil. I have this cool little gast pump that sues rigns and it pluts out moisture with no problems and goes down to 28"

[dubliner]

thanks Steve ~ now get some sleep :-)