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

thingiverse

I had troubles getting the provided IR sensor to function properly so I made a change to the design by iamburny . A minor modification has been added to the one-piece fan/heatsink duct, making it possible to swap out the IR sensor for a microswitch. This change WORKS - ten consecutive prints have now run without problems. When homing z this mod causes the nozzle to crash into the bed until the duct pivots and activates the ms. Homing the x axis uses the bulb that is installed on the acrylic xrib. Kudos go to KimBrown (father of bigblue http://www.thingiverse.com/thing:448906) for providing inspiration to use a microswitch. Instructions This modification requires a series of adjustments. Firstly, the ms must be connected into the Duet as shown on the wiring diagram. Secondly, the homing gcodes have to be changed (found last in this note). This change could surely be made smarter than my initial approach since when homing x it causes the hotend to slam into the far end of the x axis if the starting point is not very close to x = 0. Doing so doesn't cause any harm - just isn't smooth. homez: M109 S195; Setting Extruder temp to 195 prevents plastic from freezing and getting in the way. G90 G1 X30 Y30 F1500 G1 Z-220 F200 S1 G1 Z2 F50 G1 Z-220 F5 S1 G92 Z-1.6 ; Change this value to match the nozzle height relative to the ms activation point G1 Z0 G90 homex: G91 G1 Z5 F200 G90 G1 X80 F2000 G1 X-240 F2000 S1 G92 X6 G1 X3 F200 G1 X-30 S1 G92 X-13.8; set to the relative position of the ms activation point G91 G1 Z-5 F200