[kprzewodek]

I was able to broach a 3/8" hex and it appears to work quite well. I haven't put the motor through FRC type durability testing yet but so far that seems to be a good option.

Actually the rotary broach that I have goes about 3/4 of the way through the gear however I was able to carefully tap a hex shaft the remaining distance by making sure the gear was supported.

For those on the fence about investing in a linear or rotary broach I would highly recommend as we have used several times over the years. The nice thing about a rotary broach is that the main investment is the tool holder (~$300) and then you can add a wide range of cutting inserts for around $40 a piece.