How difficult was building the CNC machine?If you have basic woodworking and technical skills, you can build a CNC machine. My first machine was build from parts obtained at the local hardware/home goods store. Second one was a bit more involved, but again, parts can be obtained from on-line suppliers. Visit some forums, and you will see people are building machines in garages and basements. If you are really serious about CNC, you can also purchase a CNC machine (from places like ShopBot or K2CNC) but they are NOT cheap!
Seems expensive to get started, why the trouble? Yes, when you consider the cost of the software, hardware, CNC router etc, it will be quite expensive to put a system like this together. You can buy a quality guitar these days for much, much less. However, this is not about being easy, but about learning CNC, and then building an instrument(s) that you will have for the rest of your life, and you can say "I build it!" I can not describe the feeling to you, when you see your CNC router carve out a guitar body or neck for the first time, after having "drawn" this body/neck inside a computer! This however, is ONLY the beginning! The possibilities for building "stuff" with a CNC machine are just about infinite!
What Screws/Rails Did you use? The machine has ground Ballscrews and Hiwin rails and cars. You can use cheaper ACME screws if desired, and different kinds of rails. Usually, there are a lot of GREAT bargains on ebay...just go do a search.
What are the speeds? The machine can rapid at about 400 IPM. Careful tunning of my x-axis screw was done, since at these speeds, the screw whips, and causes the motor to stall. I have just about reached the limit of this screw, and anything faster will require either a rack and pinion design, or the recent new rotating ball nuts which have surfaced. Maybe on the next one! :-) But I really do not need anything faster..not building rocketships, I am building guitars :-)
How about drivers and Motors? I am using drivers from Keling, and 550Oz/In steppers from them as well. Plenty of torque for that I am using the machine for. The keling drivers have been awesome! I am running the motors at 48V, with about 4Amps Per phase. I am running the motors in a Parallel configuration (wired). They also have new Digital Drivers!
What Spindle are you using? I am using a Teknomotor spindle, and I should have used one sooner! It is wisper quiet, and has almost no runout! It uses an ER20 collet with a Delta VFD to drive it. Just the fact that I can adjust to any cutting speed, makes it extremely versitile!