Over the weekend I was trying to turn some steel and I found that even the lowest feed rate was too fast at .0036"/rev. I decided to dig through my box of gears and come up with a lower feed rate. I put a 30T on the shaft closest to the spindle. I mated it up with the 127T gear. Then I put a 66T on the gear box shaft and mated that to the 120T gear. That should reduce the feed to .429 of the normal rate. .0036 x .429 = .00154". That seems more reasonable.
I also noticed for the first time that the feed and threading charts say that the lead screw is 8TPI but the gearing shown seems to indicate that the leadscrew is actually metric. I've been threading imperial threads with the 40 x 120 x 40 gearset, but it looks like I should have been using the 40/120 x 127/40 transposition gearing.
According to the charts you need three completely different gear setups for normal feed, imperial threading and metric threading. WTH were they thinking?