DIY Coupling: A coupler for the motor and lead screw (from Marc K.)
This creative coupling solution comes from another generous user of the site. He has devised a way to couple the motor to the leadscrew with standard aluminum tubing. Marc has graciously allowed me to show you this creative idea.

Bill of Materials
Many of you have asked me to provide a list of materials and costs for the CNC Machine. Here, I will provide a list of the materials, costs and where they can be purchased. In the list, I will also include various alternatives for different types of applications. This may include types of cutting tools, types of motors for the axes, etc. I will keep this list alive and updated in the "stuff for sale" in lieu of a better place. Please write me with suggestions, and if you know of better prices and places to get these materials. This list is a work in progress, since I wanted to make it available immediately. Most prices are from memory, until I find my receipts somewhere in one of my packing boxes, so you may see numbers change, but it gives you a general idea.

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?!?).