Steel Frame 8' x 5' CNC - Advice Sought

[routercnc]

Yes, that was the basic idea on the spacer approach. I was looking into this a while ago (been thinking about a gantry upgrade) and you can reduce the spacer offset further with:
Custom ballscrew AC bearing housing +
Custom floating bearing housing +
Removing part of the flange on the ballscrew nut

You'll have to decide if it is worth the effort for a few more millimeters.

The diagonal plate down the centre is not worth it if you only weld at the ends. Better would be a shear panel set into each end to blank off the section. You could set the stepper motor with slotted adjustment holes into one of the plates (i.e. motor inside the section) to keep it tidy.

[BrentonSpear]

Yes, that was the basic idea on the spacer approach. I was looking into this a while ago (been thinking about a gantry upgrade) and you can reduce the spacer offset further with:
Custom ballscrew AC bearing housing +
Custom floating bearing housing +
Removing part of the flange on the ballscrew nut

You'll have to decide if it is worth the effort for a few more millimeters.

The diagonal plate down the centre is not worth it if you only weld at the ends. Better would be a shear panel set into each end to blank off the section. You could set the stepper motor with slotted adjustment holes into one of the plates (i.e. motor inside the section) to keep it tidy.

I am planning to add the end plates to stiffen things up on the gantry.