i have created a herringbone gear. i would like to the finish to be highly polished - like ball burnishing
I assume that you mean that you have created a design. Is this the gear that you created the first pic. and do you want it to actually run with a mating gear? It won't, there is no root clearance. Is the tooth flank shape based on an involute? (needed if it is to run)


what kind of machines will this require? a 4-axis for the herringbone?
Helical gear teeth are normally produced by shaping or hobbing. Although a double helical (herringbone) gear can be cut complete without a central groove for cutter pass through, they are generally assembled from one right and one left hand gear as the pump rotor gears in the second picture.

Knowing the geometry of the teeth in picture two, I cannot imagine that it (the complete gear) can be produced by milling. If it is not for running and you take a few liberties, then it might be possible.

In theory with a fourth axis, it should be possible to mill a single helical helical gear having a true involute flank and the correct root form.


i want the edges of the herringbone gear to be sharp (like the original design) will ball burnishing wear down the edges?
I recon that the corners will suffer rounding, but as Nick says "ask the supplier"



Hope you're not being put off.....

Martin