I'm going to build my Z axis later.
I've been looking at various machine builds and getting some ideas.

There seems to be two ways to approach it.

1. Fix the bearings to the gantry carriage, and have the rails move up and down with the router.

2. fix the rails to the gantry carriage, and have the bearings ride the rails , up and down with the router.

as far as I can see. with the bearings fixed, and the rails moving, it makes for a more compact machine, only being tall when the router is fully up.


Are there any pros and cons to either method ?
Rigidity ?

Unless I hear otherwise, I'm moving towards the fixed bearings design.

TIA for any suggestions

Rich