Posted by BillS on April 01, 2016 at 18:45:06:
In Reply to: Need ratio for Liebherr L 252 gear hobber posted by Aditya Patel on March 26, 2016 at 09:49:38:
I collected this differential formula and posted it into the FAQ page:
9.375 x NDP x sin(HA)
Gear Ratio = --------------------------------
25.4 x PI x Hob Starts
Also I would suggest looking at Hobbing topics in the FAQ page that might be of use to you.