Can I purchase a computer off Amazon (I have a machine I want to use) and still use the USB interface to drive it with LinuxCNC?

You will need to build the table unit for your machine. There are instructions on how to do this at the bottom of the product page here, https://www.buildyourcnc.com/Item/cnc-machine-blackFoot-v4 There is no estimate on how much this will cost though, since there are too many variables involved to do this. - PC with parallel port and USB port - 20awg stranded wires for the motors - http://www.buildyourcnc.com/electronicscombo.aspx - 18awg stranded wires for power supply to drivers - 24awg stranded wires for breakout board to drivers (location and spacing of components varies from one person to another, so we do not provide cables/wires) - General purpose extension cord (cut the female end off) to provide power to power supply - USB cable to power breakout board - Parallel cable to communicate to breakout board - Router - (optional - instead of router) Spindle with power inverter http://www.buildyourcnc.com/SpindlesAndAccessories.aspx - (if purchasing spindle with inverter) General purpose extension cord (240v) (cut the female end off) to provide power to power inverter - End Mill(s) http://www.buildyourcnc.com/ProductsEndMills.aspx - CAD, and/or CAD-CAM software (to produce geometry, machine operations, and g-code) http://www.buildyourcnc.com/CNCsoftware.aspx - CNC control software (to read g-code and control machine) http://www.buildyourcnc.com/CNCsoftware.aspx This answer is applicable to most of our machines with the exception of the greenLean and the blueChick since those machines are equipped with a table structure. Additional Information: Additional Information: Additional Information: