Cherry Pi Delta 3D Printer

*** UPDATE 13 April 2014 ***
I have released details of Cherry Pi II with many improvements incorporated:-
http://www.thingiverse.com/thing:298168

This is my own variant of a variety of 3D printer designs available. I have used ideas from Kossel, Delta Pi, 3DR and, of course, Rostock. Many thanks to the designers of those machines for their brilliant ideas that I have shamelessly 'Cherry Picked' hence the name of my design!

The rods on my printer are 277mm from steel ball centre to centre. The towers are 800mm Bosch/Rexroth aluminium extrusion and the base frame extrusions are 250mm long as are, obviously, the top frame extrusions. You need nine in all.

The bearing carriers use 6 623 10mm x 4mm x 3mm bearings and slide directly on the extrusion. Nut traps for M3 nuts are included in the carrier. The rods connect to the carrier with a plate that fastens with 3 M3 bolts, again nut traps are included. The rod carriers and the effector plate hold 10mm x 5mm countersunk, cylind