Simple 3D Gear design software recommendation

[Neale]

I think you'd get away with a standard tooth profile, tilted so it matches the correct cone angle.

I'd have to dig out the gear design/machining book I've got buried somewhere to confirm that though.

Trouble is, tooth needs to scale with distance along - tooth width and gap aren't constant. There are some standard ways of getting close using a dividing head and taking three cuts per tooth space but I'm not sure how you would fully automate that.

[Leadhead]

For clarity, I am aiming at a full 3D file to cut conventionally on a 3 axis CNC. With the axis vertical and if practical a radial toolpath.
I believe I am almost there with a bit of caddery-pokery. Makes one very respectful of Art Fernety and his Gearotic software.

[Neale]

Out of interest, what kind of size/tooth count are you looking at? Tool choice would be interesting as well - small enough to get into the bottom of the tooth but still giving a decent finish?

[Leadhead]

Currently adjusting tooth parameters to be able to rough with a 3mm and finish with a 2mm bullnose. That is, of course, the small end of the small pinion.
Not able to answer you until that is resolved. Will post a screenshot then.

[m_c]

Trouble is, tooth needs to scale with distance along - tooth width and gap aren't constant. There are some standard ways of getting close using a dividing head and taking three cuts per tooth space but I'm not sure how you would fully automate that.

Yeah, you need to take the standard form, then scale it to/from the disappearing point where the centre of the two shafts meets.
As Leadhead isn't hobbing, the variable tooth size doesn't really add to the complexity of the machining, just the designing.

Gear machining is something that fascinates me, especially when you see some of the setups and tools from pre-computer days.