Step 4 - CNC Z-Axis Part 2

At the rate I'm going, I should be finished with the entire CNC router structure (not including the lead screws, motors, or electronics). Since all of the parts are so intrinsically related to each other, I have been bouncing around. The fourth video, which I will post later tonight, will contain the completion of the z-axis and a part of the y-axis. By the end of the weekend, maybe Monday, all of the videos pertaining to structure will be posted. All of the axes will be sliding and you will start to get a greater understanding of the final product.

UPDATE: The back of the z-axis in the third video was measured 5.5"; however, since I chamfered the corners of the rail section of the z-axis to secure the aluminum angles, the length of the z-axis back was shortened. In the fourth video all of this is explained, and a convenient way to measure the correct length yourself since everyone's widths will vary.

The missing component that wasn't covered in the part 1 of this step was the z-axis rail (using aluminum angles instead of round bars) and the z-axis rail support. In addition, the back of the z-axis was re measured in a more logical way.

This is my first use of an aluminum angle instead of round bars along which the axes glide. I have to say that it was a good decision. The key is that the board had to be chamfered so that the aluminum angles are supported. Around the rail and support are the z-axis linear slide bearings and back. After testing the slide, even through many mistakes and imperfect cuts and drills, the slide feels perfect and smooth, much smoother and solid than the previous CNC router I made a while back that use round bars.

The rail support dictates the measurement of the back as well as how much space you will have for the router. I am using a 3" wide rail support, which including the linear slide rails, will allow me sufficient room for the router that I use. Measure the width of your router to see if you will have enough room. If not, use the 4" wide piece.

There is no need to fasten the rail to the rail support since the z-axis linear slide bearings and back provide a compressive force, squeezing, the rails against the rail support piece. It's a very efficient method of attachment and forgives many imperfections.

The router is used for the first time. Part 1, I recommended to purchase a router. Make the right choice and go with a variable speed with at least 2 hp if you can. The router that I purchased is single speed 23,000 rpm. With this impediment, I may have difficulties fabricating metals such as aluminum, or plastics. These materials will get gummy at that speed. When I complete the build, I may purchase a variable speed Dewalt or Kress.