Taken from the GitHub repo:

V2.4 Z-Drive Motor Tensioner Mod

Mod that replaces the motor tensioner assembly in the z drive to make it better braced and eliminates chance to rotate/twist when you tension and potentially when the drive operates. The stock motor tensioning had the tendency to flex if not tightened/installed carefully, causing the closed loop belt to easily rub against the pulley flanges. I prefer being able to lock down the entire z drive as a single unit, hence the design choices.

Unfortunately, the skirt geometry changes, so you will have to reprint the front skirts entirely. Besides that, you only need to reprint the motor bracket and the base plate for this mod.

For this reason, this mod is entirely OPTIONAL. Perhaps consider it if you are starting a new build or you wish to improve over the current z drives and are willing to print more plastic.

[Sic]

Extra parts that you will need (2x per drive, therefore 8x in total):

• 8x M3X12mm bolts
• 8x M3X5X4mm heatset inserts (the specced ones in Vorons)
• 8x 1mm M3 washers/shims (7mm OD max, optional)

The, above, parts, are included in the kit.