Quote Originally Posted by silyavski View Post
Yes, i get it. I was suggesting a steel box section profile and 2x 30x30 or similar aluminum profiles fixed on one face so you can imitate your first design. Best would be your design made from steel box.

Looking at the design, what i see is that you try to make flat the z but at the same time the whole Z assembly seriously overhangs on the linear bearings. So making it same but from steel, you could fix the rails further in front up to the near end of the steel box, which you could not do with aluminum.

I have redrawn million times this and until now i couldn't find a real way to diminish overhang without placing the ball screw behind the gantry. For a better understanding is better to draw the spindle mount brackets, the spindle itself and the bit. On the 3d warehouse there is 2.2kw spindle with mounts. So you will have better picture what you gain and at what price and compare actual bit position.

-using flat wide rails 15 size on the Z will gain you 15mm versus 20 size square rails
I'll make a drawing to see what this is like, also estimate the weights. I've had a good play with the spreadsheet but it can't do the aluminium extrusion however there is another calculator for that.