I have looked into this previously, but never actually got around to trying it, as I've yet to find a real need for it.

IIRC, all you have to do is program for a thread, dwell for a few revolutions at the bottom, then rapid back out. I can't remember where I found the information (possibly PM forum..), and you need to do a little bit experimentation to get the timings right, as the tap won't always bite at the same point, so you have to allow for a thread or two variation.

Actually, tapmatic have suggested code in their CNC tapping head manual - http://tapmatic.com/product_line_ins...e_tapping.ydev
The only thing you'll need to allow for if using a non-cnc head, is the standard heads normally reverse out faster, whereas as the CNC heads reverse out at the same speed they go in.