I will never use BK/BF blocks on my machine - yes they can work but they need a varying amount of TLC so I prefer to just make my own as then I know it will be accurate and can make it a better shape to fit the available space.


The BK blocks are just mild steel, but it's easier to machine aluminium so I use that. You need to bore the block to the width of two angular contact bearings, put a cover on the front to press on the outer ring of the bearings to retain them and if they're single row cheap bearings you'll need a shim between them. There are plenty of examples of bearing arrangements elsewhere on this forum / CNCzone.