I’ve been following Mike’s Models blog for some time now and Mike’s helped me out with silver soldering questions in the past. One of his current projects is to make some pinion wheels for a kids toy.
There are various techniques for cutting gear wheels, hobbing which uses a helical cutter with the work free to rotate and form tool cutting (gear milling, fly cutting of gears, single tooth cutting) which uses a shaped cutting tool and an indexing head to move the gear after cutting each tooth.
Mike has been trying out these different methods.
Mike also references John Stevenson’s article on Gear Cutting and I’ve found the following two references via google.