Parts!

We have parts. 

Ball screws, linear rails, bearings direct from China.

Mock up of the Z-axis

Marking out the aluminium extrusion for the first linear rail.  I used the extrusion itself for our "straight" reference.

Transfer punches were a fantastic purchase! Allowed us to easily mark the locations of all holes so we could use centre drills, pilot drills, final drill and chamfer while maintain hole accuracy.

I started with the drill press but with 240 something holes to drill for the linear rails, I started using the cordless drill and found it far quicker.

Using the drill press to guide the tap in was giving a good thread but was painfully slow.

I fabricated a simple jig with a 1/4" socket extension and a tap holder chuck (these are great) and a T-handle.  This was far quicker for tapping the holes.  (Also aluminium cutting fluid for drilling and tapping is a must, so much nicer) 

I soon found that I could reliably use a cordless drill to tap the holes.  As long as I cleaned the swarf each time.  Didn't break a single M5 tap.