I'd use belts....so how much are those ball screws going for???

No seriously like Ad's said if you plan to use it as a router as well then stick with the ball screws, they will be easier to setup, maintain and have better repeatability.


With regard to drive it boils down to speed and how much backlash you can tolerate. Ideally you would use a direct drive motor but again as stated you will need a powerful motor an if its a stepper then you will need a higher lead on the screw to keep the rapids up, but will effectively reduce the torque and you'll need an even bigger motor

Irving did a good motor calc sheet' so i suggest you look at that and get a feel for what you need. Don't know where it is tho.



also should i mount a screw on each side to stop the gantry crabbing?
If you have 2 screws available then i would use them but there are other solutions such as driving it from one side and then use belts (or cable) for the anti-racking system