The Technique of Lapping
Centerless Cylindrical Lapping
What is centerless cylindrical lapping?
It is a simple-to-use finishing method for round parts, permitting narrow tolerances, exact fits, and excellent surface finish quality. The use of centerless cylindrical lapping machines makes lapping rings or lapping stones unnecessary and produces superior quality in the shortest possible time.
As delivered ground for lapping or polishing, the parts comprise an allowance of 4-8 microns according to the surface roughness. The roundness can be improved somewhat by lapping. Best results are achieved with a pressing finger which has approximately the same radius as the workpiece.
The smaller drive roller turns the workpiece. The larger working or lapping roller removes material by means of a path or speed difference at the contact line (Figure 43) .
Special machines for diamond lapping, diamond polishing or chemical polishing already involve drive power values of 8-15 kW and pressure loads up to 5000 N per ring for a plate diameter of 500 mm.
Fully automatic machines with computer numeric control of the various
processes have been available since the beginning of the 80’s. Wear is compensated for automatically, and mass-produced parts can be manufactured at very low costs.