Why is it better to use a worm gear hob to process a gear than a gear shaper cutter?
The gear shaping and hobbing are fan forming, and the gear teeth of the machined gears are enveloped. Slotting, as long as the adjustment of feed, you can "meticulous" envelope; and hobbing, hob turn, enveloping a number of teeth only hob groove (blade) of the number, the envelope is better than the teeth.
Hob, because of processing, testing and other reasons, the basic worm is Archimedes worm, not involute worm, there is minimal principle error.
The shaper cutter is an ideal gear, and there is no principle error in processing the gear;
