Fixed Gantry Design - Input Appreciated.

[A_Camera]

I think that the first, traditional design is the best. The second one will be too complicated and it must also lift not only the Z and the spindle, but also the whole gantry. I also think that squaring the second one, and also driving up and down, would be too complicated and difficult. So my vote definitely goes to the traditional design, which is similar to mine. Milling aluminum will not be a problem.

[Electroconducive]

I think that the first, traditional design is the best. The second one will be too complicated and it must also lift not only the Z and the spindle, but also the whole gantry. I also think that squaring the second one, and also driving up and down, would be too complicated and difficult. So my vote definitely goes to the traditional design, which is similar to mine. Milling aluminum will not be a problem.

Thanks for the reply :)

You're right, the second one with the moving steel box section would be harder to square. I'd be driving the z with two 1605 ballscrews a belt and either a nema23 or 34 to avoid racking. I was thinking, given that I would really like to maximise the Z height as much as possible.

Would the steel version be more rigid at max z extension? Or, would the additional distance of the spindle from the fixed gantry in the X direction negate any rigidity advantages?

I am willing to put up with a little bit more of a complicated build for a stronger Z at full extension.

Then again, maybe I am conceptualising this all wrong and it's pointless to even attempt the steel Z.