Driving a CNC mill from Arduino/ramps (3 replies)

Hi I'm building a cnc milling machine and I want to control the machine using a spare set of electronics I have to keep costs low.

I have a spare Arduino Mega 2560, ramps 1.4 & 5 Polou stepper drivers.

I already connected a couple of the nema 23's to my ramps board of my printer and drives them both fine will be looking at motors' around the 2.3 amp range as I know these drivers will only drive 2 amp. I have heat sinks fitted will actively cool with a decent pc fan.

I have a 24v power supply 350w I would like to use to give the motors more grunt, I read about modifying the ramps board for 24v. What I wonder is do I even need the ramps board can I interface 4 steppers to the arduino, power them with 24v (Whilst Arduino is still 5v) and still use them with grbl?

Also could I use an Arduino Uno instead of the Mega as I also have 2 of them?

All I want is 24v for the motor's I think there must be an easier way than modifying the whole ramps board as I won't use the heaters.

Thanks