Quote Originally Posted by JAZZCNC View Post
Yes either works fine. Also consider attaching the motors to the screws with belts as it provides a few advatages. It Lowers resonance, allows a ratio and gives flexabilty in location so can turn motors inwards and keep width narrower.
Originally I was a bit hesitant to this idea (for sake of simplicity), but it grew on me as I considered my design from different angles.

Now, I don't want to go into to much detail before i break the 10 post threshold and can post pictures, but considering I'm planning to make the frame 1000x800mm (effective working area approx. 750x600mm), should I use 1605 ball screws on all axis, or is it better to use 1610 on X and Y (and possibly 1605 on Z)? With belts, I guess, it doesn't matter as much since I could always gear it to suit the purpose, but am I unnecessarily restricting myself if I choose one over the other? I'm thinking of using nema 23 2.4nm steppers (in case it's relevant info) and mainly work with wood (hard and soft) and occasionally soft alloys e.g. aluminium.

In relation to the above, I'm thinking of using base 30 60x120 extrusions for the long axis (for easy mounting of 20mm round linear rails) and 3 cross beams (along the short axis) of 60x60 extrusions mounted flat with the top side of the side extrusions. Essentially the frame would rest on the side extrusions and I'd have an even bed extending over the whole 1000x800 surface. I could also use 60x120 for the cross beams (which would undoubtedly make the frame more rigid), but that would force me to move the belt driving steppers outside the gantry plates (instead of hiding them under the table) which defeats the purpose of keeping a compact design. From your experience(s) would the 60x60 cross beam solution suffice or should I play it safe with 60x120 all around? Mind you, I'm constantly trying to balance performance with costs, hence, I'm inclined not to overbuild just because I can.