Step 1 - Linear Slide Bearings
This tutorial is dated, if you are considering a CNC for your personal use, we would highly recommend purchasing a kit that is very stable from our wide range of machines available. If you are looking for great linear slide bearings, see here. Through much of my research on homemade CNC machines, I found that the mechanism to provide linear sliding is simply the use of an angle ("L" shaped piece of metal), bolts or screws (5/16" at 3/4" in length), nuts (5/16") and standard skate bearings (I use ABEC7/608Z). The design is actually very efficient and clutter free. When I say clutter free, I mean that the exhaust of sawdust that the CNC will produce will not clog up these bearings. Collar bearings, or bushing bearings I believe will have the tendency to receive material within the bearing housing creating a binding effect. If you are wondering what a bearing bushing is, imagine a cylindrical tube with little balls housed on the inside surface of the tube. The skate bearing method is like creating a new kind of hybrid inline skates and those skates you used in the 80's with the four wheels (coming back into style, why?!?).

Step 12: Gantry Linear Slide Bearings
This tutorial is dated, if you are considering a CNC for your personal use, we would highly recommend purchasing a kit that is very stable from our wide range of machines available. Hey, where did that day go?? Man, time is a passin' and I just can't keep up. Well, today you will see the slide bearings for the gantry. These are very long linear slide bearings. They are long for a good reason. First, the gantry is big. Second, the gantry is heavy. Third, the gantry is made of MDF. Fourth, the gantry is made by HAND! Oh, did I say that the gantry is heavy??

Step 9: Z-Axis Lead Screw and X-Axis Aluminum Angles
This tutorial is dated, if you are considering a CNC for your personal use, we would highly recommend purchasing a kit that is very stable from our wide range of machines available. Instead of using allthread for the lead screw and a standard nut, consider using a 5 start lead screw and anti-backlash nut. It will keep you from pulling out your hair by running much smoother and faster. Lead screws... hmmm... ok, let's talk concepts. The lead screw is the main component for the transmission of power in a linear form. Yes, a little like the transmission in the car, but much simpler. The screw yields a ratio of force to the linear motion, but conversely affects the speed and resolution of linear motion. To explain in more simpler terms, take a regular screw, and a nut. Hold the nut in one hand but don't turn it. Hold the screw in the other hand and screw it in the nut. Your hand is applying a force to the screw in a circular motion, hence the motor turning the shaft, and if the screw is turning at a stationary point in space, it will pull the nut toward the hand turning the screw. If the turning motion of the screw is reversed, the nut is pushed away from the hand turning the screw.