DIY Marble - Metal Machining 3 axis CNC Router

[Halbmond]

Regarding two rails per side, or three on the Y axis:
Have you seen any commercial machines do this?
Just go with bigger rails if you need the load rating capacity.
A second rail adds a lot of cost and hassle machining and aligning. (Though it appears you have access to machines for doing this).

What are the cutting forces in marble machining? How do they compare to metals?

For cutting marble you need higher speed spindle than required for metal and less kW.
Max spindle kW for marble in the market is 15-18 kW with minimum 12.000 rpm
Actually for marble machining 9-12 kW is just fine, 15 kW is required if you gonna use 800 mm diameter saw.
If you are going to have 5 axis, each axis must have min 500 Nm torque capacity.

Min spindle kW for metal machining in the market is 15-20 kW - 6.000 rpm


I have seen lots of commercial cnc machines having 2 linear rails on each side. Paralel or different directions.
We are going to buy a new gantry style machining center. I have seen lots of catalogs.

For marble 1 linear rail is enough, for steel it depends on your y axis length.

Actually I think 1 linear rail will do fine, because my y axis is not wide much.
Expanding the rail size is better option. At the moment X axis linear carriage model : RGW35HC (Width: 100 mm) I will replace it with RGW45CC (Width: 120 mm,same length)

In our workshop we have 2 8 meters Z axis capacity horizontal and vertical CNC. You can machine 100 tons of any piece.
I will need much smaller CNC.

This CNC is for my friend and will be started to welding a couple of weeks later.