One-piece fan/heatsink duct with microswitch homing (x- and z-axis) for Ormerod 1

As I had difficulties getting the supplied IR sensor to function properly I made this modification to the design by iamburny

I've made a small alteration to the one-piece fan/heatsink duct, allowing swapping the IR sensor with a microswitch. And it WORKS - I've printed the last 10 prints or so without any problems.

When homing z this mod drives the nozzle into the bed until the duct pivots and activates the ms. Homing the x axis takes advantage of the bulb present on the acryllic xrib.