When choosing compressor you need to consider if it will be able to constantly Air Compressor For Laser Cutting china provide desired pressure and volume of air. Small airbrush compressors little compressors boast amazing pressure figures but really poor flow rates adequate limited to airbrush pistols. Also if small compressor can push enough air it’ll likely overheat in 
short while.
Our laser cutter was included with small membrane pump (Smallest on the picture), I really do not know very well what specifications it has but stream of air was very weak. It is adequate if all you want to accomplish is engrave, although actually then we got considerable smoke traces around engraved picture.
it had been rated for level of ~2.4cfm and had a 1 gallon tank which may be filled to 58 PSI. It were able to give us continuous 1 bar (14 PSI) of pressure, nonetheless it had to operate at all times and overheat badly within five minutes.
Third and current compressor we got was 6cfm rated belt driven unit with 13 gallon tank which is filled to ~100psi. With this unit we are able to run at continuous ~2bar (31psi) without fear of overheating since compressor engine is not on at all times. Using reserve air flow in tank we can also drive up to 3.5bar (50psi) for short jobs.
The best setup for me would be compressor rated to >6cfm, huge 70+ gallons tank rated to 10bar (140psi) and software air control via solenoid valve.