question about gear cutters

[G Jones]

I've been watching a ton of videos on gear cutting for watches/small clocks. it seems that a common way of doing it is to slot the gears first , and then instead of cutting them from a normal involute gear cutter, they use a special cutter with one tooth cut int the profile of the gear, followed by a sort of spiral to rotate the gear automatically to the next tooth, cut a bit out, and on and on etc, until it cuts full gear profile.

Is this corret? IT seems like a great way to minimize error, and cut very small gears rather quickly.


can anyone help explain this better? Cheers!
G Jones

 

[rgray]

Are you speaking of gear hobbing? That is done with both the blank and the gear rotating.
Many home brew worm gear builds involve gashing first for tooth number before hobbing, as starting out hobbing the blank may yield the wrong
number of teeth.

 

[G Jones]

yes, I'm talking about hobbing gears. From what I could see in the video, however, the gears were being cut very quickly, and it looked like the cutter had one leading cutting edge, and then the metal following the cutting edge angled away so that one revolution exactly stepped the gear being cut one tooth over, lining up the cutting edge for the next cut in the gear, and so on, and so on. It might help if I draw a picture, it seemed fairly unususal