Low cost manufacturing of gears

[MattRR]

I am helping someone with a new project. He will have production volumes of 50-100 units at a time. The unit has 11 gears. 5 simple spur gears, 20 pitch, .5-1.5 inch diameter; 4 planet gears about 1 inch in diameter and 14 pitch, and a ring gear that is 3 inches in diameter. Of course it is desired to minimize tooling costs as well as production costs. I am asking for input: What is the lowest cost manufacturing method? Are there any recommended sources for individual gears, or for producing the entire unit? Pitch line velocities are very low, on the order of 700 fpm and less. I therefore think AGMA 8 gears are adequate. Stresses are fairly high, on the order of 40 ksi bending for the planet gears (no reverse bending), but number of cycles is low.
I was thinking of some sort of stamping or extrusion process. Any input is greatly appreciated.

 

[livingwater]

MATTRR, I used to work with the row units on the Case Cotton Picker. Most of the gears we had were forged plates with the teeth cut in after normalizing. They were heat treated after that to handle th required forces. We did have one gear that was about 2 inch diameter that was powdered metal. It didn't have big loads, though I don't remember what the exact numbers for loads were.

Not the lowest cost on tooling, but production runs were'nt too bad.

 

[involute]

if your quantities are low then powder mettalugy is out due to high tooling costs