hello, the cooling system is designed to chill out the spindle especially for high rpms; maybe it also helps greasing the bearings ? newer models won't start if there isn't enough air pressure
there should be no problem if you cut at low rpms, for short times
try to use it in "low gears", pretty low, somehow just like how you would cut on a classical machine; less than 500 ... 1500 ?! consider also low doc, lower feeds, etc
if you were going, before, on hsm for 2 hours, now is verry probable to achieve overheat without cooling, maybe after 10 minutes ?I don't run it longer than 2 hours at a time
again, use the machine in short-runs, check periodically the temperature of the broach, by putting your hand on it ( or use a termometer, etc ) ?
at least, you will deliver things, a bit slower, but in the end maybe you will have some profit to fix the compresor
patience & low cutting specs
however, can't you find a compressor somewhere arround your neighbours ? a simple one, just to keep you moving for a while ? and use it togheter with your actual dryer, considering that you have one
i don't know man, i guess is hard for you, probably too many things in a short period of time ? all the bestbeing a one man shop