I am going to machine splines in a shaft with gear hobbing machine. The design requires a missing spline tooth (a mating part align the missing spline tooth on shaft). How do you get the missing tooth? the area cannot be flat after the teeth is removed. Thanks

So, does the shaft have a wedge shaped key on the inner diameter of the shaft....man that does not seem to be the best way to align these 2 items....spline requires special machining as does the id of the shaft.

The spline teeth is on the OD of shaft, not ID.

was referring to the id of the mating part (not the shaft with the spline teeth with a missing tooth)...assumed it was a hollow shaft or the hub of a gear.

you are right. The mating part is like a gear. Thanks

I know you can mill splines acurately because I believe the offroad industry does this with axle shafts (saw an artical in 4wheel mag with currie Ent doing this). But I beleive all of the manufacturers do something like this. Some probabably use a gear machine but others use the old school milling.

so the spot with the missing tooth on the male piece has to be the same radius as the minor dia? yuk. if a design change is not possible, or it really can't be flat then 1) facet it either by rocking the lathe carriage or in the mill and then finish with a find file, or 2) with an slot drill smaller than 2x the width of the space between splines (at the bottom) in a vertical mill and the work held in an index head, centre the work, bring the cutter down and cut the radius by rotating the head back and forth. Technically it should be a slot drill cuz its going to be like a plunge cut as you rotate - ie the last little bit gets taken out by the centre of the cutter. (At least that’s how I remember it when I did something similar)

Thanks, Mcgyver, your ideas are really helpful. Another way I am thinking is to use woodruff cutter in a vertical mill, and hold the part in the index head. But the cutter need to be formed to match the minor dia.