During the turning process of a ring, the clamping force of the chuck causes circumferential deviations in the ring wall thickness and diameter. In order to minimise the wall thickness deviations, an experimental set-up for an inprocess control of the cutting depth during turning is being developed. The set-up comprises a Fast Tool unit, an ultrasonic measurement system and a global control unit. In preliminary tests, the ultrasonic measurement proved suitable to acquire the changes in wall thickness. First turning experiments show that the developed Fast Tool unit and the applied control strategy fulfil the requirements for an in-process compensation of wall thickness deviations during standard turning conditions.