Title: Ultrasonic air bearing spindle for micro cutting


Name: Sebastian Greco


Phone: 0631 – 205 - 5938


Project description:

Ultrasonic assisted cutting provides an excellent technological potential when machining difficult-to-machine materials such as titanium, ceramics, tungsten carbide, or glass. The superposition of the conventional cutting motion with an additional tool vibration in the ultrasonic range leads to improved material removal as well as to changed cutting conditions. These can increase the efficiency of the cutting process significantly. For rotating tools, the ultrasonic vibration is induced with ultrasonic excited main spindles. In order to exploit the potential of ultrasonic cutting for micro machining, new spindles are necessary. Today´s ultrasonic excited main spindles provide comparatively low rotational speeds and high run out errors. Consequently, the existing spindles are not able to achieve the required cutting speeds and accuracies for micro tools (d <50 μm).



1. Step: design of an ultrasonic stimulator for the use in air bearing spindles

2. Step: numerical design of air bearings for minimum run-out at high rotational speed

3. Step: design and construction of an ultrasonic excited air bearing spindle

4. Step: milling tests


Expected Results

It is expected to build an ultrasonic excited air bearing spindle that reaches sufficient rotational speeds to enable the use of micro tools with d < 50 µm at adequate cutting speeds. In order to observe high accuracy in micro machining the spindle operates at high concentricity. After the milling tests, a deeper insight of ultrasonic assisted cutting is expected.