M A. Donmez

A defect-driven diagnostic method for machine tool spindles

Simple vibration-based metrics are, in many cases, insufficient to diagnose machine tool spindle condition. These metrics couple defect-based motion with spindle dynamics; diagnostics should be defect-driven. A new method and spindle condition estimation device (SCED) were developed to acquire data and to separate system dynamics from defect geometry. Based on this method, a spindle condition metric relying only on defect geometry is proposed. Application of the SCED on various milling and turning spindles shows that the new approach is robust for diagnosing the machine tool spindle condition.

Evaluation of an Inexpensive Method of stabilize the Temperature of Machine Tool Components

One of the best approaches for maintaining a uniform temperature across a machine tool structure and thus minimizing thermal deformations is removing the heat at the heat sources. This study evaluates the effectiveness of using inexpensive Personal Air Conditioner (PAC) tubing to remove heat from heat sources. The PAC tubing is a soft silicone extrusion with small, perforated slits through which cooling air is transferred. The PAC tubing increases heat dissipation from the heat sources through local forced convection and Coanda-effect cooling. The results of a series of tests conducted on a simulated motor showed that the motor shell temperature was reduced 28-fold compared to natural convection cooling. This leads to a conclusion that PAC tubing may be a viable alternative to cooling machine tool components to minimize thermal deformations.