How large of a air compressor must I have in order to run this?
What plasma torch do you plan on running?
You could probably limp a 6 CFM by with some pausing.
9 CFM would probably be the lowest output for consistent use on thinner stuff.
Most plasma manuals will recommend two to two and a half times the CFM requirement of the cutter for CNC applications.
So this falls in the neighborhood of 12 to 16 CFM as a recommendation.
Hypertherms and some other brands have very sophisticated air use technology so likely less air usage than most units out there for the same operation.
The amount of air used is clearly marked on every single cut chart for hypertherm for every different operation. So if you’re going to do a particular operation you could look up in the car chart to see exactly how much air that’s going to consume.
The answer is relative to the plasma equipment you plan on using, the type of operations you plan on carrying , and the duration of those operations.
The reason they would like a compressor that’s two to two and a half times the size for CNC operations is that these longer duty cycles will cause things to heat up hot air doesn’t release moisture as well and issues will start to happen.
Myself I run a 18.9 CFM air compressor at the shop. The plasma isn’t the only thing on the system though. I had a 9cfm for quite a period of time but I found with longer operations my air temperatures would start to go up.
Welcome to the forums.
If you provide some more detailed information of what you want to accomplish with your CNC table choosing a air compressor will become a lot easier.
The other thing to keep in mind is the more air drying and piping equipment resistance you have between the compressor and the plasma the larger output your compressor will need.
Ultimately increasing the size of your compressor to overcome resistance is not as good of a solution as reducing your resistance.
3 Likes
@TinWhisperer as usual is giving great advice makes some really good points here:
You will be dealing with warmer air and allot more moisture issues if you skimp on compressor cfm. I would recommend keeping it close to the 12 cfm range minimum. Really most air tools operate best with a compressor running in this range.
In a CNC plasma application, I recommend installing an after-cooler between the compressor pump and tank and using a water separator in that loop to prevent most of the condensed water from getting into the tank at all. An after-cooler will keep air going to the plasma unit at or just barely above ambient temperature particularly when the pump is running. Hot air is bad as stated above because it is super-saturated and once that air hits your consumables it will release that moisture. And if you use PEX like I did, hot air will weaken the plumbing too.
Something like this: Dry Shop Air - Step 1 (Compressor After-Cooler) | The Hobby-Machinist
1 Like