How is a traditional hobbing machine set up to cut a spur gear?
All “traditional” gear hobbing machines have an Index Constant. This constant, along with the number of teeth to cut and the number of starts in the hob cutter determine the index gear ratio and the index change gears. Some typical Index Constants are: 36, 30, 24, 15, 12, 10, etc. Let’s take an example using a single start hob cutter.