Rear-mounted Duet enclosure for RepRapPro Ormerod 1

This is an enclusore for the Duet controller board, to be mounted on the rear of the printer atop the power PCB (which also goes into the same enclosure). This is similar to where it is mounted on the Ormerod 2. Parametric design where most dimensions on the enclosure are easily customisable.
Based on existing work by bobtidey and dc42, see sources for links.