[pippin88]

Larger ball screws do have higher axial rigidity

Longer and double ball nuts have higher axial rigidity

[CallumRD]

Larger ball screws do have higher axial rigidity

Longer and double ball nuts have higher axial rigidity

Yes, of course. The question was what performance issue was being attributed to a lack of ball screw rigidity? What evidence was being followed that lead to the conclusion that the ball screw rigidity was at issue?

Broadly speaking, I'm not a fan of upsizing everything because 'bigger must be better' and that kind of mindset in general. I like to understand the forces, components, and design parameters that make up the system so I can chose appropriate components for the design and intended application.