Hi there, i'm new to CNC and i'm about to build one, for the electronics I'm going to use Arduino uno and cnc shield V3.0, for the motors, i cant use 17HS4401 stepper motors, work with 1.7A and 3.4V ? CNC shield work with 12V.
If this is the CNC shield you're describing then your motors will work fine with 12V. The higher voltage will allow more speed from the motors but you do need to ensure you adjust the drivers to stay under the 1.7A current limit of the motors (as well as whatever current maximum the drivers have). Typical stepper motors and drivers are fine up to ~35V.
Use your finger and check the temperature of the driver chips and the motors. If anything starts getting so hot that you can't hold your finger on it for more than two seconds then you need to reduce the current more. You should expect things to get hot -- the two second rule tells you when it's too hot.
You may find some useful info in Stepper Motor Basics
...R
thank you for all