More robust belt paths for Voron Switchwire (#657)

* adding first version of the mod

* renaming the files to respect proper name

* fix formatting of readme

* add pics of install

* adding clarification in the readme

* readme formatting

* readme formatting

* better name and link to master readme

* table formatting fixes

Co-authored-by: Jan 'Yenda' Trmal <jtrmal@apptek.com>

printer_mods/README.md

@@ -347,6 +347,7 @@ like so:
 | | [V0 PiCam Mount](./xbst_/V0_Picam)| A Raspberry Pi Camera Mount For V0 | :heavy_check_mark: | :x: | :x: | :x: |
 | | [DuetZero](./xbst_/DuetZero) | Pi Zero mount over a Duet2 for space saving | :heavy_check_mark: |:heavy_check_mark: |:heavy_check_mark: |:x:|
 | Xceled | [Single Panel Magnet Mount](./xceled/Single_Panel_Magnet_Mount)| Mount your front panel using only magnets | :x: |:grey_question: |:heavy_check_mark: |:x:|
+| Yenda | [SW More Robust XZ Belt Paths](./yenda/vsw_more_robust_belt_paths)| Small mods to belt routing components to ensure a better/more robust alignment | :x: | :x: | :x: | :heavy_check_mark: | :x: |
 | Yeri | [V0 Magnetic Panels](./yeri/V0_Magnetic_Panels)| Mount V0 panels with magnets, removes need for hinges and lets you easily detach sides for access | :heavy_check_mark: | :x: | :x: | :x: |
 | | [V1 3Z](./yeri/V1_3Z)| 3Z mod for V1 | :x: | :heavy_check_mark: | :x: | :x: |
 | Zen3D | [V0 Handle](./Zen3D/V0_Handle)| Voron0 Handle for 3mm panels | :heavy_check_mark: |:x: |:x: |:x:|

printer_mods/yenda/vsw_more_robust_belt_paths/readme.md

@@ -0,0 +1,61 @@
+# More robust Voron Switchwire belt routing
+
+This mod was created because the original stock parts didn't work well for me. 
+The major part are the moded stepper cages. The stepper cages got tilted usually 
+during tensioning and leading to the axle of the stepper not being parallel 
+with the horizontal plane, which lead to yawning of the belt and increased wear 
+and tear of the belt. Additionaly, the cages parts a and b had the tendency 
+to open up in the bottom,  especially when the tensioning screw is one or two mm too long.
+
+The modded version has a through-screw in the bottom and additional screw slot
+on the top to attach it to the vertical extrusion, to help with proper leveling
+of the stepper axle. You'd probably be able to address these issues without
+if you were careful and knew about them. Using this design is just much faster.
+![Stepper cages](images/motor_cage.png)
+
+## Additional mods ##
+
+The **xz blocks** have a slot for M5 button head screw that can be used to fix
+tilting of the blocks w.r.t. the plane defined by the X gantry extrusion.
+The original blocks have already some measures to prevent this, but apparently
+those were not sufficient in my case (I was worried about tightening the screws
+too much, as the plastic already started to give and yet there was still a bit of
+tilting play). 
+![XZ Blocks](images/xz_blocks.png)
+
+
+The **upper xz** blocks/supports were modded just to help more carefuly define
+in what position and orientation the blocks should stay. These have the least effect, IMO.
+![Upper XZ blocks](images/upper_xz.png)
+
+With these, I had printed almost 400 hours without any belt-related issues and 
+the belts look still fresh, no signs of fraying.
+There exist also similar unofficial mods on Voron discord addressing similar issues
+but I think this is the most exhaustive version.
+
+## Print Instructions
+
+**Print Settings:** Standard Voron PIF sttings -- at least 40 percent infill, 4 perims, 5 solid layers top and bottom
+
+**Quantities:** Quantities are noted in the filenames -- each part needs to be printed only in single copy.
+
+## Installation
+Install should be fairly straightforward, the naming of the parts should follow the original naming,
+so you could follow the SW manual.
+Few pictures
+![Stepper cage 1](images/install_cage_a.jpg)
+![Stepper cage 2](images/install_cage_b.jpg)
+![Stepper cage 3 and XZ blocks](images/install_xz_blocks.jpg)
+![Upper XZ blocks](images/install_upper_xz_blocks.jpg)
+Please note that the last picture contains an old revision of the upper XZ block (that was
+reducing the Z travel), but the provided version installs the same way and does not 
+reduce the Z travel.
+Generally speaking, I suggest tightening the screw attaching the stepper to the vertical extrusion
+as a very last step. 
+
+### Overal BOM
+- 6x M5x10 BHCS
+- 6x M5 T-Nut for 3030
+- 2x M3x16 SHCS
+- 2x M3 Threaded Insert (standard "Voron")
+