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SB 9C 116T Gear in place of 80T


Jul 19, 2022
I recently acquired a 1947 9C and found that there is a 116T screw gear that was used in conjunction with a 108/18 gear for fine feeds.
This is not listed on the thread/feed chart of the machine.

Calculating the feed rate when using the 116T, 108/18 and a 16T stud gear comes out to 0.0029"/rev if I did this correctly.
This is higher than using the 16T stud, 54/18. 72/18, and 80T screw gear which comes out to .0021"/rev but still close.

My question is can you use the 116T screw gear along with the 16T stud, 54/18, and 72/18 to produce a finer feed of .0014"/rev.
Will this combination fit using the standard 2 fork banjo.

I would like to know if this combination is possible before I try to purchase the 116T gear as I am not sure if there is sufficient room for this combination.