Dui, ni shuo de dui
Well, that is still quite an aggressive setting, I’m impressed.
70% width is quite a lot, but if it works fine, then go for it. During my tests I’ve set it up to 50% or less.
Do you have a workshop air compressor? You could easily hook it up to the cnc, then just add a simple valve to set up the air flow, and a flexible tube to get it where you need. You could even add a solenoid valve to start/stop it whenever you want.
If you don’t have an air compressor, well… buy one! It is one of the most useful tools around the shop, a must have! Plus it doesn’t cost too much, a small 30 liters one should be enough.