Greetings- I have just finished a gear hobbing attachment for my non universal horizontal mill. The arbor is driven by a gear train, and I had to fabricate a small table to obtain the lead angle offset of 1.7 degrees.
I am using a 16 DP, 14-1/2 PA hob with straight rows of teeth. Hob is about6 cm. in dia and 7.5 cm. long. I am cutting spur gears.
I am having problems with gear tooth thinning. I also see rough machined surfaces .
I feed by hand, probably 1.0 mm. per revolution of a 40 tooth gear blank while the mill spindle is running at 375 RPM , cutting aluminum.
I get better results by not feeding continiously- just feed one mm, wait for the blank to revolve once then feed again.
Would appreciate any comments, suggestions as I am new to hobbing. My gears cut with single involute cutters look much better. Thanks, Jim.