Hiwin linear blocks HGW 20 CC - what preload to spec?

Hello,

Please can anyone let me know what preload they have used on home build CNC router machines when using HIWIN 20 mm linear blocks. As I understand there are ZB, ZA and ZO, I have tried a ZB and a Z0 and a ZB has way too much friction for my Nema 23 3NM motors, so the choice seems to be either Z0 or ZA.

I plan to use the improved SW seals


Many thanks for your help
Rob

Ive always gone for the Z0 Light preload i think its just right for the home grown even some serious machine builds.