Ormerod1 Duet PowerPcb Combine

2015-08-29 update
now support “Duet Shield”, revision some hole


like jstck 's "Rear-mounted Duet enclosure for RepRapPro Ormerod 1" http://www.thingiverse.com/thing:478829.

and, that use Ormerod 1.0 's stl on github.com as a reference.Parameters more accurately.

Note:
(1)you need to upgrade Y-axis form Ormerod1 to Ormerod2.This is necessary to adjust the vertical distance between the aluminum and the back-end.
(2)Add four M3 flat head screws, four M3 nuts, two 15mm copper cylin