I was having a thunk the other night about making gear hobs, not cheesy ones but nice big stonking ones with 3/4" or 1" bore, 12 slots and machine relieved in HSS.
Read up on the commercial ones and also some articles from Model Engineer and Model Engineers Workshop.
Found some interesting points out and I may have found a way to do these easily on any centre lathe. Still neeeds a bit of work on the subject, I rang Ivan Law up, the guy who wrote the very good Gears and Gear Cutting book and he's also looking into it.
It looks like it's one of those things that's been around years but no one has latched onto it.
I regularly speak to Dr Giles Parkes on the phone at least once a week. He's the guy who did the hob relieving attachment in issue 56 or 57 of MEW.
Facinating guy, he's in his 80's but as bright as a button. He was one of the original engineers working on the Enigma decoding machines at Bletchley Park, or Station X in WWII.