I've got two cyclones, one crap, the other not. One connected (in part), the other not. What I need URGENTLY to know is whether Bob L's No 2 option at the machine is preferred. I intend running from a 200mm main line to 150mm steel with a minimum of 150 mm flex. Isn't that enough? Otherwise, I will have to run 200mm down, then choke it down via a tapered reducer to 150mm. I am well into $10K on dust extraction and the sheet metal guy arrives tomorrow..... Pressure, pressure.