Been so long loosing all my math so need help. On a drill press to use a 1725 RPM motor driving a 12" diameter pully connected to a 22 tooth sprocket on same shaft driving a 45 tooth sprocket into a 30 tooth sprocket that turns the shaft the chuck is mounted on what size motor pully do I need to get the bit speed down to a hundred RPM or 150 RPM. Only plan on using this press for 5/8" up to 1" bits so I need a slow speed. My supposedly good drill press from TSC 15+ years ago on the slowest speed is faster than I would like (think around 600 rpn) for 1/2" bits and I run it on that slowest speed all the time for all bits, think they call it a 16 speed and it is only fast, extra fast and out of this world fast. This one that I want to get going is one that you could either put a motor on or use a hand crank.