V2.4 MGN12 X-axis mod (#261)

printer_mods/README.md

@@ -35,6 +35,7 @@ like so:
 |albert|[IKEA Dioder Led Mount](./albert/IKEA_Dioder_Led_Mount)|A mount for the IKEA Dioder LED strip | :grey_question: | :grey_question: | :heavy_check_mark: |:x:|
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+| |[MGN12 X-axis](./arkeet/mgn12/)|Replaces the dual MGN9H rails with a single MGN12H. |:x:|:x:|:heavy_check_mark:|:x:|
 |claytono|[Voron 2.4 Extrusion Jig](./claytono/2.4-extrusion-jig)|A jig help align extrusions to get a properly square frame |:x:|:x:|:heavy_check_mark:|:x:|
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printer_mods/arkeet/mgn12/README.md

@@ -0,0 +1,60 @@
+MGN12 X axis
+============
+
+This replaces the dual MGN9H rails on the V2.4 X axis with a single MGN12H
+rail.  The belt is directly clamped to the MGN12 block by the carriage.
+
+The stock PL-08N probe is not supported as it is too long.  Use one of the
+alternatives listed below.
+
+Thanks to joshmurrah, hartk, and everyone else who helped out in one way or
+another.
+
+Required hardware
+-----------------
+
+In addition to things you can reuse from the stock build, these items are
+required:
+- 1x MGN12 linear rail with MGN12H carriage (same length as the original MGN9
+  rails)
+- 1x M3x40 SHCS
+- 4x M3x8 __BHCS__ (or 2x BHCS and 2x SHCS)
+
+Supported probes:
+- Omron TL-Q5MC2 (use M3x25 or M3x30 screws)
+- Panasonic GL-18HB/18HLB (use M3x25 or M3x30 screws)
+- Panasonic GX-H15B/HL15B (use the 9mm probe bracket and M3x16 screws)
+
+Instructions
+------------
+
+Assembly is similar to stock V2.4, see the assembly images below.
+
+The belts are clamped between the carriage and the MGN12H block.  This
+procedure worked for me:
+1. Loosely fasten the carriage to the MGN12H block using the M3x8 screws.
+2. Push the belts in on the left side, until they are just visible in the
+   middle.  Tighten the screws on the left side a little bit, to secure the
+   belt ends.
+3. Push the belts in on the right side as far as you can, and pull them out
+   through the middle.
+4. Tighten all screws, while making sure that all belts are firmly held in the
+   clamp teeth.
+5. You may wrap the extra length of belt around the probe cable, as in the
+   photo below.
+
+Please check the Z endstop position after assembly as it may have changed
+slightly.
+
+Images
+------
+
+![X-axis rendered](Images/x_axis.png)
+
+![Carriage rendered](Images/carriage.png)
+
+![Carriage assembly](Images/carriage_assembly.png)
+
+![Carriage mounting](Images/carriage_mounting.png)
+
+![Photo](Images/photo.jpg)