Easy to Build Desk Top 3 Axis CNC Milling Machine





Introduction: Easy to Build Desk Top 3 Axis CNC Milling Machine

Here is a way to make a computer controlled milling machine. That puts the real power of a computer control machining into the hands of the average human. Small enough to set on the desk but scalable to any size. As inexpensive as possible without sacraficing accuracy (too much). All most all the parts can be purchased in local retail stores. And above all CHEAP you can be up and running for well under $200. With it you can do 2 Dimentional engraving and PC board etching and 3D milling and modeling in Foam, Wood, Plastic and other soft materials.
Also try watching the YouTube movie at the end (the last frame).

New information on the Motor Driver Circuit is (HERE).

Step 1: The Frame

The frame needs to be a flat base that you can mount everything on horizontally and a goose neck of some kind to hold the Z axis (the up and down part with the motor tool)firmly in place. I used one inch pipe just for fun but as it turned out it was pretty handy too. When I needed to make adjustments I could just tap it with a hammer. As you can see the post that holds the Z axis doesn't have to be in the center. It just needs to be firm and the water pipe does a good job of that. Later, after you are sure all the pipe joints are in the right place, you can add a drop of thread sealer to the joints and it will be a good solid structure.

Step 2: The X Stage Rails and Motor

Next its time to add the rails for the X axis stage. These rails are 3/4 inch U chanel aluminum that you can get from the hardware store. Put a washer under each end to space the rail off the pipe just a bit. Don't worry about the rails being perfectly parallel. You'll see why later. Now mount the stepper motor with a bracket like you see here. Connect a length of 1/4 by 20 threaded rod to the motor shaft with a short piece of rubber hose (1/4 inch fuel line). Now your ready to set the movable part of the X axis(the stage).

Step 3: X It Stage Right

Take a piece of plastic(I used Plexiglas) or metal, something strong and flat and mount a piece of the U channel to it. Now the tricky part. The round thing is a bearing. You can get them out of motors or buy them at a hardware store. Mount it to a short piece of aluminum like so. Then take a 1/4 in. coupling nut(a long nut) and wrap it with aluminum like so(see pic.) The bearing will hold the X stage to the X rail and the coupling nut will allow the motor to run the satge back and forth. It wouldn't hurt to grease the skids a little and the nut too.
Here's a video on making the bearing fixture.

Step 4: The Y Stage

The Y stage is just like the X stage but turned 90 degrees. Mount two rails and a motor on the X Stage and then take another piece of flat material and a U channel and make the moving Y stage. Make the little bearing thing and a coupling nut for it too. When your done it should look like this.

Step 5: Zee Z Axis

Again we are going to reproduce the X and Y Stage to create the Z axis stage. Take a flat piece, here I used a piece of white Plexiglas. Mount some rails and a Motor to it. Then make a moving stage piece with a u channel and a roller bearing. We'll do something a little different with the nut(see picture). The four posts you see on the stage will hold the motor tool. Now since this stage is going to move up and down the weight of the motor tool will make it want to come off of the rails so lets add a few more roller bearings to each side to keep it together.

Step 6: Get It Together

Now we slap the motor tool into the Z stage. Then its time to mount the stage to the frame. And there you have it. This is the mechanical structure. From here we will need to hook up the stepper motors to a controller and get some software running on the computer but I'm going to save that for future articals.

Step 7: What's It Do

If you were interested in this project it's likely you have already seen what can be done with an 3 axis(XYZ) computer controlled milling machine. What is suprising is what kind of accuracy you can get out of this thing after you tinker with it a little bit. Make sure all the rails are held firm and straight. Tighten the roller bearings so the stage doesn't shift.
I used it to make PC boards. It's real good for engraving name tags and signs. And it's pretty exciting to see it carve a 3D object out of a block of foam or plastic.
WARNING there's a lot to learn about the software. Some venders offer package deals of motors, drivers, and software. That makes it easier but you pay for it.
I'll add more to this later. Send me comments and questions.

Step 8: Easy Mill the Movie

If the literal instructions are confusing try watching the YouTube movie:

Also check out the follow up instructions on Stepper Motor Control: Easy Mill Stepper Motor Controller

Step 9: Engraving

Now that I got the machine back together after making the instructable and I did some engraving and made a PC board.
Cutting plastic is no problem but doing the PC board the bit went a little too deep on the left side of the board and took out all the finer traces. This is when you start tweeking on it. Just take some aluminum foil and put it under the rail of the Y axis. So as the stage travels left to right the height of the bit should stay the same.
Notice I'm just holding the material down with masking tape. What I like about this thing is, it's easy to fix these kinds of problems because it's all made from simple elements.
Here's the new video:

Also check out the follow up instructions on Stepper Motor Control: Easy Mill Stepper Motor Controller
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    965 Discussions

    Hey Tom, great project! I had a lot of fun building this and as soon as I can scavange a DB25 cable, i will be able to use it. Here are some of my pictures. The table is 9"x11". I added a simple fish tank pump to blow off the dust. The plexiglass extenders allow the router to utilize the full 9" x11". I will be posting pictures of my slightly modified circuit board.

    8 replies

    Hi crred

    What motors did you use for your build? IE: size, torque voltage...

    And what controler are you using?



    Hello I am a beginner, if you can be with you help I have stuck to trapezoidal Data do not know. Thank you.

    sir,will you please tell me the diameter of x-y axis shift and what is the size of thread on that shaft for e.g(1 mm, 2 mm or 5 mm)...please

    Considering you've finished yours, do you think that a machine with 10" x travel would have to have 20" x rails, or is my logic screwed up? Thanks, snow

    Wouldn't the extenders flex and cause the table to move? Either up/down flex due to the weight of the Stepper, or torsional flex as the motor moves the table?

    the weight of the table itself, the anchoring provided by the x axis motor provide stability and prevent wobbling of it.

     This is my version of Tom's CNC. It uses the stepper motor 3 Axis CNC Driver Kit from chromationsystems.com (Jeff from Chromation Systems was a ton of help and his instructable is here: https://www.instructables.com/id/Parallel-Port-3-Axis-CNC-Driver-Opto-Isolated/) and I am using KCAM for the software. I named my machine CNCme. You can also watch the Youtube at: http://www.youtube.com/watch?v=Uzli11WJeo4.  Thanks Tom, Jeff and Instructables. 

    2 replies

    The slides are off a network hardware cabinet.  I purchased them from a local surplus store.  They are very nice because they run on ball bearings.

    That looks like an excellent version of this instructable!  Is there a possibility of you doing an instructable of your panel?  Looks great!

    hi tom, i too was inspired by your simple design, and actually guided a high school project based on your designe, the hope was that it will enable students to make low cost pcb in school. after the project(wich was a bit diffrent from yours and didnt works all that well duo to my lack of technical skills and experience(im 18) and other things) ended i decided to make a V2 wich is almost the same as yours, and it dose work well,i manged to see it do very presice things with a pencil. the problem is i cant find a right drill for making the pcb's,(im pretty sure thats it) i got this 8 pcs kit from drill bit city but the drill that dose the routing dose not have a pointed tip in the very end and there for dosn't penetrate the circuit until much pressure is applied but then it goes in way to deep, im guessing its the drill bit but id like to hear what you say, and maybe recommend me a drill or a set from drill bit city or anywhere else(take in account i live in Israel ) my main goal is PCB's although i already did some name engraving and it came out very well! 1 more thing... is there a way to use lazycam with kcam? and what do u think about mach3 it look way more complicated is it any better?

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    3 replies

    Wow! I like the design of the machine in the last three pictures... Do you have any kind of build log for it? More pictures? What did you make the frame out of? Thanks, snow

    hi, yes sure there are plenty more pictures at my website (sefi.tk) the frame is made from U channels alone, it was a much much more stable design yet it requires precision with assembly cutting and the whole process, out of my experience, after building 3 models, its clear to me that the cost of a stable machine is it requires more precision in ever step of the way, if you have experience, tools, and two right hands then go for something stable, otherwise stick with the basic plans. btw i solved the whole pcb making thing by getting an endmill and made already a bunch of pcb's and many other thing, thanks alot tom. hopfully my next project will be my own instruct-able :P

    Regular Dremel engraving cutter (#105) works fine for me. It's 0.8mm wide and I use it for PCB Isolation Routing. You can find it in any hardware store (Ace\Home-Center\Rosenfeld) here in Israel.