Tapping Guide (M5) for OpenBuilds V-slot

I'm building a D-Bot printer; This one: http://www.thingiverse.com/thing:1001065. I'm using V-Slot extrusions from OpenBuilds for the frame.

When it came time to tap the extrusions for M5 screws, I needed something to help me keep my non-self-guiding taps perpendicular. This was my solution and it worked very well: a guide for an M5 tap. It slips onto the end of the V-Slot extrusion and you put in your tap and start. I generally let it get going, then pull the tap, remove the guide, and finish without it - you need to back out a bit every couple of turns to clear the waste and keep the tap from jamming. Once you get the tap started, you don't need the guide anymore.

I used the profile http://www.thingiverse.com/thing:884966 created by SanderSae for the extrusion shape. I re-worked some of the values so I could difference() the shapes to get the correct profile for the slot inserts. Thank you SanderSae.