Thanks Jeff and Frosty,
Frosty, the correct way as you pointed out may be for a later point, but might be achievable with just doubling the scale of everything and sourcing some larger bearings. Not sure how the motors would cope with lifting that extra weight. I plan on building a few iterations including one with geared steppers so that could end up in one of them.
Jeff, mesh levelling does seem the way to go to be absolutely certain with the cuts, I’ll look into it once the other half of my end stops arrive, will certainly help me with the finer details in carving.
Frosty in your link inside the post Jeff mentions, there’s a bit of confirmation for 2 ideas of reducing sag that I was thinking of implementing after a walk around the workshop.
Firstly, inside the tube, epoxy a length of 2-3mm flat bar vertically to act like an I beam, eliminating Z axis sag without much weight gain and still allowing for cable runs.
Secondly, the aluminium angle used for the vacuum hose, printing a second pair of supports a second channel can be fitted to stiffen the x and y axis to some degree. I found an aluminium 50x50x3 extrusion in the workshop today with ridges to increase rigidity but also reduces weight comparatively, a test bend of the 3.0m ( just under 10’ ) long stock I had showed about at 5-8mm deflection on the edge/angle and nothing noticeable when bending from the sides.
Sorry about all the metric I’d try convert to inches but I’m not sure what the standard fractions or equivalent stock is so the result would be laughably wrong no doubt.