I really like my air-cooled spindle as well. The air intake is at the top of the spindle - a very long way from where the cutting is going on. I always run dust collection - so dust at the top of the spindle is not a concern for me. Here’s the one I purchased - looks like it’s out of stock at the moment: High-Torque Stepper Motor, Stepper Motor, Driver, Stepper Motor kit, DC Servo Motor, DC Servo Motor kit, Stepper Motor Power Supply, CNC Router, Spindle, and other Components.