Newsletter // March 2013

Available Ultra-Precision Work-Holding Spindles are used to hold and position workpieces for turning or milling, but often lack robustness, load capacity, and thermal stability. With the introduction of their new Ultra-Precision Work-Holding Spindle, the ASD-Px, Levicron now offers a solution for all of these challenges. With a load capacity of 2,000 N (axial/radial), a stiffness of 200 N/µm (radial/axial), and a spindle warm-up time of less than 9 minutes, the ASD-Px is the most robust and thermally stable work-holding spindle available.

One topic raised by many customers is the sealing air function of our spindle products. To address this, Levicron has developed the “sushi” sealing air test.

The precision of a spindle, whether used for holding the workpiece or the tool, is defined by the so-called error-motion number. This number accounts for all asynchronous and synchronous spindle errors, excluding the fundamental error—run-out. When considering an electric motor driven by a PWM drive and a high-speed spindle, it’s important to note two challenges: the data required to directly measure a spindle error at high spindle speeds—such as above 50,000 rpm—and the influence of high-frequency vibrations from the motor, which cannot be recorded in real-time. While there are methods to reduce these data, Levicron has developed new FFT and multi-probe techniques to measure nanometer-level errors at high speed and to account for high-frequency influences from the motor.

In addition to the above topics, readers can find Levicron’s solution for a universal aerostatic bearing system for turbochargers. Please refer to the PDF for more information.

Newsletter Content:

• ASD-Px – Ultra-Precision Work-Holding Spindle with industry-leading performance and thermal stability
• An unusual Sealing Air Test – the so-called “Sushi Test”
• Spindle Error-Motion – New methods for high-speed spindles