Z axis system for CoreXY printer 5mm rod & lm12uu bearing

This is a my design for my new Core XY .. its using LM12UU bearing and 5mm Rod

also 20x20 sigma profile(extrusion) connector part for z table .. I will put more picture about it..

Q:Why there is 3 hole in Z-Axis-Corexy-5.STL file ?
A: Because if you wanna do 4 motor on Z axis ( each Linear Bearing Rail has own rod and motor ) you can cut this part from middle and can use also 4 pieces

new version for Lead Screw -
RepRap 3D Printer THSL-500-8D T-type stepper motor Lead Screw Dia 8MM Thread 8mm Length 500mm with Copper Nut Free Shipping

I bought a Lead screw ( this one:http://www.aliexpress.com/item/RepRap-3D-Printer-THSL-500-8D-T-type-stepper-motor-Lead-Screw-Dia-8MM-Thread-8mm/32465980465.html ) so maybe you can use it too..

Regards