Abs plus (#411)

* Update materials.md

* Update materials.md

* Update materials.md

* Update materials.md

* Update materials.md

* Update materials.md

* Update sourcing_faq.md

materials.md

@@ -21,7 +21,10 @@ PETG has a glass temperature of around 85 ºC. It has moderate stiffness dependi
 
 ## ABS
 
-ABS has a glass temperature of around 90 ºC. It has moderate stiffness and moderate ductility.  It is the primary recommended material for Voron printers due to the high temperature rating and moderate ductility.  This allows for the parts to hold up in a higher temperature environment well yet endure some flex without cracking.  Both of the variants ASA and ABS+ are also fully supported.
+ABS has a glass temperature of around 90 ºC. It has moderate stiffness and moderate ductility.  It is the primary recommended material for Voron printers due to the high temperature rating and moderate ductility.  This allows for the parts to hold up in a higher temperature environment well yet endure some flex without cracking.  The variant ASA is also fully supported.
+
+Note on ABS+ and other blended ABS products:  
+ABS comes from a well-known basic chemical formula (Acrylonitrile Butadiene Styrene), however manufacturers of ABS+ filament don’t offer us much information on what makes their filaments “Plus”. Some brands claim reduced odor and toxic fumes, which may be related to a lower percentage of styrene. the variability in the chemical composition of ABS+ filaments means that consistency across brands cannot be guaranteed. As such, ABS+ is not recommended for new builds given the unknown mechanical properties.
 
 ## Nylon
 

sourcing_faq.md

@@ -43,7 +43,7 @@ No, you can substitute ball spring post-assembly nuts from Ali just as easily in
 
 ### Why do you recommend generic linear rails vs a Hiwin or THK genuine rail?
 
-- We are not imparting cutting forces onto the carriages on the rails (ie: side loads), so the low preload and ok tolerances are good for this application
+- We are not imparting cutting forces onto the carriages on the rails (ie: side loads), so a medium preload lieanr rail is fine. the most important aspect is to not have any "slop" or "play" between the rail and carriage.
 - A set of 7 V2 rails is the cost of one genuine mid-grade THK rail.
 - Clean all of your rails, then grease them (there are numerous videos on YouTube on how to do this). Pick your best rail for the X axis, then the Y, use the worst on the Z (if applicable).
 
@@ -76,7 +76,8 @@ Materials not supported, these are all not designed to take repeated heating and
 
 ### What lube should I use?
 
-The currently recommended lube for the linear rails is Mobilux EP1 or EP2, or the NLGI equivalents. Either Super Lube or EP1/2 is recommended for the extruder gears.
+The currently recommended lube for the linear rails is Mobilux EP1 or EP2, or the NLGI equivalents. Look for a lubrication with a synthetic base oil with a high viscosity (above 100mm^2/s) these will work best.
+Either Super Lube or EP1/2 is recommended for the extruder gears.
 
 ### What kind of bolts are what?