Introduction: Simple CNC Machine

About: Making Stuff since the 80's
What I'm going to try and show you in this instructable is how to build a simple CNC machine.

Now when I say Simple I mean you only require basic tools & materials to build the machine.

The machine is made out of Sawn Timber, drawer sliders, nema 17 Stepper motors, a TB6560 Driver Controller Board and a Dremel Trio as the milling/cutting tool

I started about year ago trying to build a CNC machine, I tried a few different designs but i struggled to get the building of them right. This was mainly down to the complexity of some of the designs and the lack of equipment I needed to build them and the money that they cost. So I went back to the drawing board and tried to build a machine that was easy to make and used readily available parts to keep the price down. The machine that i've produce seems a little ruff around the edges but the results of the stuff made have been ok

The Video Gives a quick overview of the Machine

Step 1: What You Need

CNC Driver and stepper motor kit
Ball Bearing Full Extension Drawer Slide
A computer to run Linux EMC2 software (the computer will need a parallel port)
A copy of Linux EMC2 (which is fully functional CNC control software)
Wood
Threaded Rods
Nuts
Bearings
A routing tool (I've used a Dremel trio)
Pulleys
Polymorph

A miter Saw
A hot glue gun
Drill
Screws and Screw driver

What you need video

Step 2: X Axis

The X Axis is easy to make if you think of it was square with a Drawer slider on each side and a threaded rod running down the middle.

First we need to cut 2 lengths 400mm long & 2 Lengths of 430mm

In to the 400mm lengths we need to drill a hole for the bearing to sit in. A hole will need to be drilled half way through one length and all the way through the other

The bearings now need to be placed in the holes and attached in to place with a bit of glue

Now the 4 sides need to be assemble in to a squared and screw together, ( I used 1 and half inch screws)

Attach the drawer slides to the to longer sides.

Add the threaded rod & nut in to the hole add a little bit of glue on either side of bearing to stop the threaded rod from coming in and out.

cut a sheet of mdf to go top of the A-Axis and attach it to the drawer slides.

Once done you need to cut to lumps of wood to clamp the nut from moving. These can be attached to the MDF Sheet

Once this is done you need to screw the A-axis to the base sheet.

You can at this point attach the motor but I found it easier to wait until all the axis where finished before doing so


The video give an overview of how the A-Axis was build

Step 3: Y Axis

First we need to cut some lengths of wood

2 x 400mm
1 x 500mm
4 x 300mm

The 2 lengths of 400mm long need holes drilling 100mm from the top for bearings (like the A-Axis)

The Drawer Sliders now need attaching to the 500mm length

After this is done the 2 400mm lengths need screwing to the 500mm length 

Attach 2 of the 300mm lengths to one side of the drawer sliders and the other 2 lengths of 300mm on the other side of the drawer sliders.

Add the threaded rod &  2 nuts. Add a little bit of glue on either side of the bearing to stop the threaded rod from coming in and out.

Cut 4 lengths of wood to go on the top and bottom of the nut attach these to the 300mm lengths which are attached to the drawer sliders. Glue the nut into place

Cut 2 more lengths to join the bottom of the 300mm lengths to each other

This is a quick video of overview of the Y-Axis Build

Step 4: Z Axis & Tool

 The drawer sliders need to be attached to the 300mm lengths of the Y-Axis

Cut one lump of wood to go In-between the 2 300mm lengths at the top in to this a hole needs to be cut for the bearing this hole needs to go all the way through the lump of wood. 

A Length of wood needs cutting to add to the bottom of 300mm lengths of the Y-Axis. A hole needs to be cut halfway through for the bearing.

Now add the threaded rod threw the 2 bearings. Its important to make sure the Threaded Rod & the Drawer Sliders are all level.

measure and cut a small sheet of MDF to fix the tool to. Once the tool is fixed in to place attach the MFD Sheet and tool to the drawer sliders.

I've used Polymorph to make a mounts for the mill tools

You now need a length of wood to go in between the  2 drawer sliders at the top you also need 2 lumps of wood to sandwich the nut. 

Attach the Y-Axis & Z-Axis to the base sheet. Next cut some lengths of wood to act has support struts it is important to make the Y-Axis level both vertically and horizontally

An overview of the finished Z-Axis

Step 5: Motors & Wire Up

The motors now need attaching to the machine. I've used Polymorph to make motor clips to keep the motors in place.

The pulleys need placing on to the threaded rods & the motors and then they need glueing in to place.

Once the motors are in place add extra wire so that the machine can move without the wire getting caught

Step 6: EMC2 & Google Setchup to G-gode

This is a quick intro on what software to use to make the CNC machine do something.

The software used to produce the DXF and g-code works on Windows Linux Or Mac.

The Software used to operate the stepper motors is EMC2 which, is a turnkey linux distro with EMC2 CNC application set up and ready to go.

You will need to read the getting started guide for EMC2 to help you with setting up the software.

EMC2 reads G-code which is then used to control the machine. To produce G-code, first you need to draw what you want to cut out in a package like Google SketchUp or AutoCad 123.

The program needs to be able to export a file type called DXF, If you are using google SketchUp then you'll need to install a this plugin

Once you have done the drawing (make sure you make it the right size) export it to DXF (select lines)

Now that its been exported you need to turn in in to g-code, this can be done using a program called "dxf2gcode"

All you need to do is open the DXF file in dxf2gcode and export it to g-code. The file that has been produced can now be opened on EMC2

Step 7: Test It Use It

Well that's it.

I won't pretend that once its build every thing will go smoothly all the time but it will let you try & build you cnc skills.

I think that the machine build is just the start of the learning experience

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