Ultra-precision machining using the lathe with the on-machine measuring system

The linear collider is required to accelerate the electron and the positron more than the typical circular accelerators. The key parts of the linear collider is the oxygen-free copper disks called "Accelerator Cells". The precise dimensional tolerance (less than +/- 2 mu m), fine surface roughness (less than 0.1 mu mRZ) and a lot of cells (over 2 million) are needed in the manufacturing of the cells. So the ultra-precision and high efficient machining has to be achieved at the same time. Consequently, to achieve the required qualities, new ultra-precision lathe was developed. And the on-machine measuring system was installed on this lathe. This system can measure the diameter and the thickness of the cells without contact before machining. And the cells can be machined without loss of time and the error when the cell is remounted. From the measurement result of the cells by the coordinate measuring machine, it was confirmed that ultra-precision machining within the dimensional tolerance +/- 2 mu m. And 34 minutes in machining time became possible. Thus, it was proved that the on-machine measuring system could function effectively.