This mini mill has been mounted to a square column mill .Also the driven pulley was modified on the spindle to less than 1:1 runs at 6300 rpm been running now with 26hrs on it so far with no brg breakdown .A 12 v puck fan was mounted to the rear opening were the guts used to be same voltage as the transfomer inside the speed controller.I have been cutting production runs that last 40 to 50 minutes at a time runnig 3/16 end mill 3 flute carbide doc .1 to final cut of .63 thru .625 aluminum 6061 cutting speed 28 inches per min.