Introduction: Build a CNC Router From Scratch (Part 1): Complete Video Tutorial
Completely build a CNC router from the ground up without plans, just your hands, some cheap materials and basic tools, and common sense. Did I mention you don't need plans? It's easy, and I guide you through a process of building that the measurements are derived through a logical approach, so all the pieces will fit and the structure will be solid. Moreover, you'll be able to build a CNC with almost any dimension.
And when you finish Part 1, don't forget to head on over to Part 2 where I detail the z-axis and y-axis and I start on the Gantry.
A while back, I built a very shabby machine and I knew there must be a better design. You will be able to take advantage of what I've learned from a great depth of research on the internet and personal building, testing and experimentation.
The instructable will be very long. I will probably take the cake on the length, so I'm separating the instructable into several parts. This is part 1 if you haven't already determined that. It is this long due to the amount of detail I will be providing. Since we are discussing detail, I will also provide almost all of the detail via video. Pictures say a thousand words, but video must be exponential. I really hope you enjoy this series and provide comments to help me improve and be more effective.
Even though there is another instructable on building a CNC router, it details a completely different approach and I feel that this video series will contribute to the understanding of mechanical components and unique building methods.
What is a CNC router you ask? I will define it as a computer controlled router, where the router will move on three axes and the computer controls the motion for these axes.
What you'll need:
95% of the structural components can be found at the local hardware store, like the MDF (Medium Density Fiberboard). Have the hardware store do most of the cutting, you'll mostly need 4" widths by various lengths (you don't know the lengths yet because in this build, you can make almost any size CNC router). Don't get particle board. Aluminum angle 3/4" and 1/8" thick.
A few basic tools like a screwdriver and a miter box saw. Both are pretty inexpensive and 4" width pieces usually fit into a miter box saw, especially if it plastic and the miter box can flex a bit. A circular saw would be helpful, but use the hardware store cutting service to your advantage.
A couple of links that you may find useful for these types of builds are cnczone.com. My official build of this machine is here at my site BuildYourCNC.com with almost all of the video step, but don't cheat and skip to a later step. The series is developed to follow a logical process to get measurements, etc.
Step 1: Linear Slide Bearings Video
The CNC router would be useless without a way to move the router on the axis without play. Linear slide bearings are the answer. They enable a very stable and smooth sliding motion without binding. this method of bearings has been used many times, so you can be sure they will work.
The slide bearings are one of the most important component to the CNC router, and it's good to get the concept down in the beginning. You will need about 6 of these in the CNC build at varying sizes (the gantry slide bearings will need to be much longer than the y and z axes.
You will need regular skate bearing (609zz), 5/16" nuts, 5/16" x 3/4" bolts, various drill bits and a 5/16" tap/drill bit set.
Step 2: Right Angle Joint Video
Another concept to get out of the way is the joint that is used throughout the build. I'm using 1/4" bolts and nuts. The bolts are 2.5" long to reach the nut. You simply drill a 3/4" hole to receive a nut and a transversal hole, the size of the 1/4" bolt. Since the screw is centered through the middle of the piece, the boards can be used to tension things like the slide bearings. You'll understand this concept better throughout the later video tutorials.
If cross dowels are desired, I give some instructions how to use these.
Step 3: Z-Axis: Two Videos
Now let's get started on the actual meat of the build. You will start with the z-axis. The z-axis is the axis that will move the router (or any other cutting/extruding/drawing/spraying/heating tool) up and down.
Two linear slide bearings will be needed here at approximately 3.5" long. You will also need a piece of MDF 4" wide and a length that you will be able to cut several pieces. You will also need a router for this step because the rails will be aluminum angles and the angles need 45 degree chamfers to be securely held in place. Who knows, maybe you can use this tool as the main cutting tool for the CNC, so it's justified.