Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

That is really something!

I think I understand the theory here, and both the video and the drawings for the fixture look pretty clear to me; however, I'm not at all sure about the gear cutter you used.

I'd like to try cutting gears (spur, helical, or both) for a variety of small engines, but don't know what cutter pitch, OD, and bore to choose as an all-around set of 8. Can you help with this? I ask because the size of your inline six seems to fit the relative size of things that I have in mind....

Hope this makes sense to you.