How can I speed up travel on this Boxford router? What new stepper motors to get?

[magicniner]

Do you mean increase the supply voltage to the drivers so that the drivers send a higher voltage to the motors? I assumed that they were regulated internally so that a change in supply voltage does not effect the output voltage.

Here is the data sheet for the drivers
http://pdf.datasheetcatalog.com/data...onics/2666.pdf

I also don't know how it is possible to increase the voltage to the motors without increasing the current.

The drivers limit current, this does mean that they can limit voltage but the performance increase comes where higher voltages are required to deliver the rated current to the motor.
Your current drivers (no pun intended) will be delivering full available voltage on a regular basis without that being enough to deliver the full rated current through the steppers.

[Nicholas Collier]

See my edit on the previous post, I think I figured out why it will work.
You advice is very helpful, I was just trying to understand the details.