Safety Alert!

In September of this year one of the CSRMA members had a drill press malfunction, sending shrapnel at velocities high enough to cause damage to the building where it was housed.  The purpose of this alert is to share the make and model number of this particular drill press so that you may inspect yours or take it out of service until the manufacturer determines the cause of the failure.

Drill Press Manufacturer: Wilton

Drill Press Model:  20" VSG Drill Press, model #2025

Incident Summary: The spindle pulley (part number 502731) on the drill press disintegrated, sending fragments through the protective shroud.  Pieces were still moving with enough force after punching through the shroud to break windows and chip surrounding walls.  Fortunately, no one was injured.

Current Status:  Wilton has taken this matter very seriously and is currently performing an investigation into the incident, including a metallurgical analysis of the fragments, to determine the cause.  They will notify CSRMA of the results and of any corrective action that needs to be taken when the investigation is complete.  This information will then be passed on to the CSRMA membership.

Current Recommendation:  The spindle pulley is precision balanced as part of the manufacturing process, thereby eliminating a significant source of dynamic loading.  The component is made of class 30 gray iron, which is widely used in the machine tool industry.  However, the pulley in question contained internal fractures that caused concentrated loading, which led to fatigue and then to failure.  Two likely sources of such fractures are:

1.  Incorrect casting process

2.  Damage incurred during "in-field" repairs

Therefore, I am recommending that any CSRMA member with one of these units have the spindle pulley inspected for signs of wear or incorrect casting by local qualified machine tool repair professionals.

If you need further assistance in this matter, please contact David Patzer at (415) 371-5430

or at dpatzer@rfdriver.com .