Cherry Pi III

Update 19/08/2014
Added improved filament spool holder and disc and also a wiring grommet for where the cable bundle from the hot end and extruder stepper pass through the Z tower extrusion. The hole in the extrusion should be drilled 180mm from the base of the Z tower stepper mount. This allows full travel on the Z carriage with the 225mm rods (tube length) that I use with the 8mm drilled ball bearing and spring/string retention system. I normally drill two 5mm holes adjacent to each other and file the bridge between them out to form an oval. I've also added some detailed assembly images and a drawing that shows where the T nuts in the lower base are required.
Update 08/08/2014
I've changed the design of the delta rods. Instead of using magnets I am now using 8mm stainless ball bearings drilled with a 4mm diameter, 4mm deep hole. They are sold for some sort of use in photography. Readily available on ebay. The effector and rod carrier designs have been changed so that they have