Hey dsc.

I wouldn't make the guide any taller due to M6 taps generally not being that long - in its current state I'm already losing 2cm of plunge off the taper tap - although for the depth I'm tapping it's not really an issue. Any deeper and it probably would be. The boss bores are a smidge over the diameters of the drills/taps so there really isn't that much flapping about.

Yep, in its current state the grub screw leaves a little crescent shaped mark on the plate, but I have some nylon tipped grubs on order to solve that problem!

Cheers.

Wal.