Machine-Care

The ball screw drives the feed axis on a deep hole drilling machine. It converts motor rotation into linear movement of the spindle carrier or workpiece. A worn ball screw causes inconsistent feed rate and poor hole quality. I have replaced enough ball screws to know that preventive maintenance is far cheaper than dealing with a failure during production. Ball Screw Inspection and Condition Assessment I check ball screw condition by measuring the backlash annually. Backlash is the play between the ball nut and the screw, and it indicates wear in the recirculating ball tracks. The measurement procedure is straightforward but requires careful technique to get consistent readings. ...

I have developed this maintenance schedule over years of running deep hole drilling machines. Regular maintenance prevents most unexpected downtime, and the cost of a skipped check is usually measured in broken tools and scrapped parts. The schedule divides into daily, weekly, monthly, quarterly, and annual tasks. Problem Description Deep hole drilling machines combine rotating spindles, high-pressure coolant systems, hydraulic feeds, and precision guide bushings in a single integrated system. A failure in any subsystem stops production. The most expensive downtime I have dealt with came from neglected items — a rotating union that failed because the seal was never inspected, a coolant hose that burst internally from age and pressure, and a spindle bearing that ran hot for weeks before it seized. ...