Discussion on "Productivity in the manufacture of worm gear units" at the Halifax Section of the Institution

Mr. I. C. Hopkinson: I would like to ask if Mr. Everest has ever experimented with thread whirling for the production of the worm? Does the hob with th^ carbide teeth at the end come under that heading? Is it applied to a normal, conventional screw thread? Secondly, on the same subject, has centreless form grinding been applied for your finishing operations? Mr. Everest elaborated on the care taken in getting down to 30 micro-inches on the worm, but did not make any mention of the finish obtained on the wormwheel from the finish reaming operations. Is it not so important on the wheel as on the worm?