BoltHobber - a tool for tapping hobbed bolts

I got inspired to this tool when trying to get [radus' bolt hobbing tool](http://www.thingiverse.com/thing:151669) to work with my assortment of M6 taps. The hobbing worked well, but I had troubles to get my tap through the bearings and once the bolt was finished, I had some difficulties removing the tap and the bolt without damaging the hobs...

This is when I thought that the hobbing tool should be such that the tap can be moved against the bolt, allowing this way to vary the cutting dept