I'm going to need some help.

[asbo]

Thanks for your input Jonathan.
Do you think the "significant deflection" would be a couple of millimetres or worse than that?
I wonder if I could make do with one ballscrew to start with and replace it with two later on? Moneys pretty tight at the moment.

As for the frame design, does having the rails directly under the gantry improve the rigidity, compared to other designs I have seen with tall gantry sides? like this:
(not an actual design, I just deleted some bits to show what I mean)
Building it like this would save money but would it compromise the strength of the design?