Update Bill-of-Materials.md (#110)

Author: dudewithan02

wiki/Bill-of-Materials.md

@@ -52,14 +52,22 @@ x1 per toolhead
 - [2] m3 heat inserts
 - [2] m3x8 BHCS (optional in v1.1)
 
-### Xol / A4T
+### Xol
 
-- [2] m3x45 SHCS **magnetic** (backplate lower mounting screws)
-- [2] m3x12 BHCS / SHCS (backplate upper mounting screws)
+- [2] m3x6 BHCS (backplate lower mounting screws. m3x8 will be too long)
+- [2] m3x20 BHCS (backplate upper mounting screws)
+- [2] m3x8 BHCS (extruder mount to backplate)
 - [2] m3x6 FHCS **magnetic** (preload screws. m3x8 will be too long)
 - You will **not be able** to use stock 2.4 Z joints with Xol or A4T.
 - Replacement of your Z joints with something with a lower profile such as [hartk123's GE5C Z Joint](https://github.com/VoronDesign/VoronUsers/tree/main/printer_mods/hartk1213/Voron2.4_GE5C) or [Ellis'Short Z Joints](https://github.com/VoronDesign/VoronUsers/tree/main/printer_mods/Ellis/Short_Z_Joints) is necessary to avoid bottoming out your Z carriage on the deck panel when using Xol or A4T.
 
+### A4T
+
+- [2] m3x45 SHCS **magnetic** (backplate lower mounting screws)
+- [2] m3x12 BHCS / SHCS (backplate upper mounting screws)
+- [2] m3x6 FHCS **magnetic** (preload screws. m3x8 will be too long)
+- You will **not be able** to use stock 2.4 Z joints with Xol or A4T. See links in Xol section above for links to alternative suggestions.
+
 
 ## Endstops