Originally Posted by
hanermo
It looks like a job for a T&C cutter grinder setup, with perhaps custom dressed wheels, wheels dressed to shape.
Corners may be a problem, or not.
If you can do the gears on a T&C, you could likewise burnish the surfaces using a same shape wheel of maybe carbide.
Or maybe get a steel wheel coated via PVD or similar.
Carbide blanks are not too expensive, coating tools is not too expensive, both under 100$ afaik.
Burnishing the herringbone would be quite slow, via homebrew cnc.
This makes the gear somewhat expensive.
If it takes 10 minutes, your cost to produce is about 5-10$, each.
You would need to pay off the wheels, burnishers, cnc kit, in some reasonable time, and 30-50$ / work hour to pay off everything else.