Since we repair spindle tapers, we check drawbar force on every machine possible. I've seen machines that had a force of zero on the gage and they still are running, complaining of finish problems. It is one of the most overlooked specifications. We recommend checking force every 6 months, or whenever there is any other repair being made. THe clamp-rite is a decent gauge for the price. You are mainly looking for a change in clamping force. Get a baseline and watch for any significant changes. We use a Command adaptive dynamometer which let's us check any size taper from 30 to 50. Keep an eye on those forces and the condition of the taper. Bell mouthing will occur over time and with a weak unattended drawbar problem it will happen faster. A tight drawbar and properly ground taper can make a night and day difference in operation of the machine.
Spindle Grinding Service Inc