First, the spindle goes into an exhautive evaluation. We perform multiple tests on the shaft and taper such as vibration analysis, measure of the draw bar retention, inspection of the surface contact and the test bar at 30 to 300 mm. Then, we establish the grinding mesure requirements and start to grind the spindle with our mobile CNC. Once the process completed, we proceed final tests like verification of the drawbar retention and the test bar at 30 to 300 mm. In addition, we are measuring the angularity and the gauge point of the taper with the STOTZ system.