Published on 18 Apr 2016. Written by Sushanth Ranjan
Designing and building any machine have a potential of being a good or bad experience. This is also the case when you are building an Arduino based CNC machine. In the past 5 years, there has been an increasing number of businesses and hobbyists invest in CNC machine. The concept of CNC machines are fairly straightforward, but one can quickly be overwhelmed by it. There are many advantages of owning a CNC Machine. Homemade CNC can cut and carve most of the materials. For any student, this opens many doors.
Projects plays a vital role in improving skill as well as in boosting career opportunities for an engineer. Building a project will expose the practical side of a student. Project based learning will lead to interactive education and create a deeper impact on the student. Most of the project involve teamwork or programs where students are required to work in a group. On the other hand, it also makes the learning part more fun as students are able to grasp more while learning it in a group.
When you start to build Arduino based CNC, there will be series of workflow to be followed in order to complete the project. Understanding the workflow will help you to start correctly.
One should choose the design based on the requirement of your machine. Basically, structural design can be categorized mainly, One with the mobile bed and other with the mobile gantry. Both has its own advantages and disadvantages.
With Mobile bed design one can build a strong gantry which will not flex under load. This is because the gantry is stationary and does not have to be light or conform to a certain size to fit your linear bearings.
Most of the CNC Machine are of mobile gantry type. It is tricky to design this as the gantry has to be lightweight as well as strong to carry weight. This design is very versatile.
Cutting area or the machining volume is also another important prerequisite to be known before we start building a machine. Once we decide the cutting area we can approximate the size of CNC Machine.
Machine size is basically the travel of X,Y, and Z axis. Machine size mainly depends on the design one choose and the machining area they select. You do not need to waste space in your CNC. Ideally, the travel should be equal to machining volume of your CNC.
The tools and materials can define your design almost as much as any other factor. Hobby CNC machine are constructed from all types of materials. One can see machines made out of plastic, wood, MDF, aluminum, steel, and others.
The material from which you construct your machine should be based on 3 criteria, budget, tools you have to work with, and materials available. It is hard to say which material is best as it varies with the design. We have seen machines made from MDF that hold better tolerances than those constructed of solid metal.
That is why it is crucial to choose your materials ahead of time. Of course, your hobby CNC router will probably integrate many materials. However, you will have a certain material that will make up the bulk of your machine. The right design for a wood machine is not the right design for an aluminum or steel machine.
The tools you have may also define the type of material you must use. If you do not have access to a milling machine or heavy metalworking equipment, then it may be hard to build your design correctly out of metal. This will eventually lead to a poor overall machine.
Controllers are the brain of the CNC machine. It connects the computer and the mechanical components. The controller receive conditioned signal from the computer or the indexer and interpret those signal into mechanical motion. Most frequently used controllers are Arduino Uno R3 with GRBL shield (Open source software) that takes G-Code commands from serial and turns the commands into motor signals.
There are many aspects of electronics which is very vital to the function of CNC machine. This should be checked before we buy them. Things like controller, stepper motors, motor wire, has to be inspected to build a reliable machine.
Before building an Arduino based CNC machine one should learn the basics of design, electronics, controllers, and materials. This can be done through Project-based learning which is primarily designed for such kind of learning. Check out this link to get a feel of Project-based learning on Arduino based CNC.