Effect of Forces on Gantry Cross-Sections?

[Iwant1]

How about using components from my yellow and your green, tada.

I added a 60x45mm extrusion in between the top and bottom extrusions. These can all be bolted through from the top and also screwed into the 10mm back plate. Now your worry about the weaker wider section is dealt with, plus that extra piece for 800mm length is only £12, sweet.

[WandrinAndy]

How about using components from my yellow and your green, tada. I added a 60x45mm extrusion in between the top and bottom extrusions. These can all be bolted through from the top and also screwed into the 10mm back plate. Now your worry about the weaker wider section is dealt with, plus that extra piece for 800mm length is only £12, sweet.

Thanks Adil, that looks incredibly strong in all directions... my gutfeel is it's even stronger than GREEN!

Jazz's GREEN looks by far the simplest to build and has better accessability for changing belts and pulleys... certainly if this is to be done within the gantry ends... as my current limited space dictates a compact design. And it moves the ballscrew away from the mess of the cutting chips, but also away from the profile-rails.

Your YELLOW looks the strongest, and brings the ballscrew between the profile-rails, but also closer to the mess of the cutting chips.

Anyway, my beddy beckons and tomorrow is but another day to decide....