Search:

Well it looks good but there are a few things I would comment on.

3500mm is a mighty wide gantry, it would be better from a rigidity standpoint if you have could have the axis running the other...

I like to use this calculator to calculate the Tangential cutting force, that is how hard the machine is pushing the bit sideways through the material. In my experience you can bet any...

Maybe, try a few out. It depends on your steppers, drivers and how well they work together, there is probably a sweet spot. I would stay clear of the really high ones though, mircosteps aren't always...

The distance traveled per revolution with rack and pinion is the pitch circle of your pinion gear diameter * pi, for example 1inch 25.4mm pitch circle diameter pinion gear, 25.4*3.145 = 79.883mm...

The problem is at 3m long your going to need quite large screws so that they aren't flopping & wipping around. Large screws generally have a large thread pitch, plus you'd want to use a large thread...

Is this machine to be used only for marble? I would have thought the only way to machine marble would be very slowly. In which case the maximum speed of the machine would be of little importance. So...

Kinda hard to see whats going on but you definitely need a wider gantry with 2 carriges per rail like this
16857

Fixed a few little things and added a new feature, it's possible todo any number of down ups.