Air Supply Question,New User of 45CSA

[ralphk47]

Hi Guys,
I'm a new user to be of a 4 x 8 water bladder CNC table.I just purchased a Hypertherm 45CSA unit to mount on it.My question has to do with air supply so I'm asking some of You seasoned veterans.The book calls out for 6 cfm@90psi.I have a Rigid with 4.5 gallon tanks that the label says 6.2cfm@90psi.I was going to put a couple 10 gal reserve tanks on it and try it.Problem one is on the Rigid website I can't find where this unit supplies this CFM.I hate to buy a couple storage tanks that I cant use.Any suggestions as to what kind of reasonably priced units I could buy.I'm set up in my garage so space is sort of an issue.I havn't yet seen where I could get a unit to supply this amt of air other than a large 220v commercial unit.Help Guys!Your wisdom would be appreciated
Ralphk47

[jimcolt]

You have just enough compressor for the plasma system....however you can expect the compressor will be running pretty much full time when you are cutting. Adding extra storage for the air will allow for longer cycle before the compressor has to turn on...but will not add any additional flow (cfm). A rulle of thumb for cnc plasma cutting is to have the compressor flow rating at least double the plasma flow rating.

Jim Colt Hypertherm

[flyinwilly]

I had the same problem with a compressor that was rated much higher than yours,18 CFM at 90 PSI ,and it was just large enough to run the cutter (pmax 65). It has a 30 gal tank and I think the main problem was the storage capacity. Also, take the manufacturers ratings with a grain of salt. They never put out what they are rated at.

I added a second compressor with a 60 gal tank (same pump as the first) and it will run the cutter with no problem. However, with only one compressor running, I generate a load of water. Must be because of the pump running more often and getting quite hot.

You will also get a pressure drop due to the air dryer (absolutely required) and any plumbing you have (air hose, fittings, etc.). With your pump rated so close to the requirements and the very small tank, I think you will be getting a lot of low pressure alarms.

I built my compressors with bare pumps from Eaton Compressor. I used the 3 cyl pumps with a 5HP motor. The pumps are made in China but they run very well and Eaton stands behind the units if you have any trouble. The 60 gal unit cost me a total of $450.00. I got the tank off Craigslist with the motor, pressure switch, etc. for $100 and the pump was $350.00 so shop around and you can find something.

Good luck,

Willy