What is GCode?

-Code is the common name for the programming language of CNC Machines. Somewhat of a generic, catch-all type of term for CNC programming language. Very few machines adhere to this standard today. There are as many variations as there are manufacturers. This is how I think of G-Code. It is a simple language built off of the Cartesian Coordinate System for motion control. That is a mouthful.

I don't know if that is exactly right, but you will get my meaning in a second when we go through some code line by line. You will remember your High School Geometry soon enough. For the real pros out there, you know there is much more to G-Code then that, but it is a good place to start thinking about it.

You will see many variations of the G-Code name like:

Gcode
gcode
G-Code
g-code
G Code
G-Code

Are there other "Codes?"

In a word...Yes. We will get to that in a moment. G-code is also the name of any command in a CNC program that begins with the letter G. G-Codes generally tell the machine to perform an action. G-Codes can tell machines to move a certain distance in the X-Axis for example. Or, make a rapid move to another location. Or, move in an arcing fashion while milling. An on and on and on.

Here are some examples of G-Codes:

Remember these codes change to a certain degree between CAM Software packages and CNC Machine Manufacturers.

G00 Rapid positioning
G01 Linear interpolation
G02 CW circular interpolation
G03 CCW circular interpolation
G04 Dwell
G20 Programming in inches
G21 Programming in mm
G28 Return to home position
G40 Tool radius compensation off
G41 Tool radius compensation left
G42 Tool radius compensation right
G43 Tool offset compensation positive
G44 Tool offset compensation negative

Why does G-Code Change?

We humans like flexibility. We also like standards. G-Codes are standardized in a certain sense. Once you start to be able to read it, you can read just about any flavor of it. That is the standardized part. All machines are not created alike. Even identical machines are different to a certain degree. They may not have the same tools loaded or they have been slightly modified to produce a certain type of part. Interesting how people like to customize.

That is why G-Codes are not the same. You need some flexibility in the programming to accommodate all situations. Couple that with the fact that every manufacturer thinks their version is the best and you get a myriad of G-Codes out there.

Many manufacturers also try to force you to only use their code. For example, they give you a design interface to make parts and a CAM interface to produce code. They lock you into their "Black Box" so you can't go elsewhere for service and support. They lock you in their "Family." Sometimes they make up a completely different kind of G-Code language that no one can understand but them. They do that to keep your hands tied up.

What is an M-Code?

M-Codes are related to G-Codes. M-Codes control different machine functions. Some of these functions are turning the machine on and off. Turning the spindle on or off. Turning a plasma torch on or off. Turning coolant on or off. You get the idea. When programming your CNC machine you may need to perform these functions.

Like G-Code, M-Codes vary from manufacturer to manufacturer and from machine to machine. As you can imagine you would need an M-Code for turning a plasma torch on and off on a CNC Plasma Cutting Machine. You wouldn't need an M-Code to turn a spindle on and off though. Hey, the machine doesn't even have a spindle. It's a plasma cutter!

Ivan is active in Gcode and CNC Programming.

G-Code is one of his expertise.

CNC And CAD - Computer Aided Design

CAD stands for Computer Aided Design or Computer Aided Drafting. CAD was developed in the early 60s. Today it is the premier way to design, develop and optimized products. People use CAD every day to design virtually every product you see. Generally, designers use CAD to design a product, and then produce prints to manufacture that product. A print is a picture of a part or assembly that is very exact. It includes the dimensions and a parts list used to manufacture a product. CAD is the use of computer based software packages that assist engineers, architects and other design professionals in their designs. CAD is the part of the main designing process and involves both software and sometimes hardware. Current software packages range from 2D vector based drafting systems to 3D solid and surface modelers.

Computer Aided Drafting software packages can generally be broken into two groups. The groups are 2-D drafting packages or 3-D drafting packages. Most all software packages are moving to 3-D design. 3-D design is really the next generation of CAD. Utilizing 3-D design, engineers can make a model of their product. They can then look over this model for any apparent defects before it is ever made.

CAD is used to design, develop and optimize products. CAD is mainly used for the engineering of models and/or drawings of components. It is also used throughout the engineering process from concept to design of products. These products can be used by end consumers or used in other products. For example, you can design a bolt in CAD, and then use it in a Sub-Assembly in a planetary, which is a part of an earth-moving machine. CAD is also used in the design of tools and machinery. Finally, it is used in the design of all types of buildings from sheds to shopping malls.

Ivan Irons runs http://www.cncinformation.com/CNCBlog/ were you can get the latest on auto cad blocks, computers aided design, and CAD Blocks.

Guide To CNC Machines

 

CNC machines are used in a variety of industrial settings and in woodworking shops. Most are out of the price range for the individual user, but can be purchased used for about half the price. These machines increase speed and accuracy when doing large jobs or repetitive tasks.

How CNC Machines Work
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CNC machines are used in a variety of industry, manufacturing processes and woodworking shops. CNC routers are used for drilling holes. Some machines have the capability of holding several tools. This allows them to perform more than one operation at a time. They save time and improve accuracy.

CNC stands for Computer Numerated Control. This technology was first seen in the 1970s. The machines need to be programmed and set up properly before operation. Once the initial set up is completed, they are fairly easy to operate and keep running.

In CNC routers, they can be programmed to drill holes in an automatic fashion. This is faster and more accurate over several pieces than in manual drilling. The results are more uniform. This method is very beneficial for larger jobs that require a lot of drilling. Manual drilling can become tiring and when the operator becomes tired, the results can become inconsistent.
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Types of CNC Machines
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A CNC lathe is a good piece of equipment for cutting wood. These come in models ranging from fifteen to forty horsepower. The amount of power you need depends on the amount of wood you will use with the lathe. The best models operate in several different modes, from completely manual to all CNC. This allows you to tailor the machine?s operation for each project.

A Bridgeport mill is the best in milling technology. Mills are used in many industries, both large and small shops. They are efficient and reliable. Bridgeport mills are built to last a lifetime. However, they are very expensive. The price is out of the range that most people can afford.

The CNC mill is a specialty piece of equipment. It uses computer programming and robotics for accurate operation. The results are more accurate than any person could ever achieve. For this reason, Bridgeport mills are often used in the airline industry. Once the specs are entered, the CNC decides which tools need to be used and automatically changes the tools as needed.

Engraving equipment is made to engrave a variety of materials including glass, stone, metal, wood, composites and many others. The machines mark and engrave with more accuracy than could ever be achieved by hand. Everything from large signs to small lettering can be done, depending on your needs.
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Buying Used units
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CNC equipment is very expensive and out of the price range of most people. Buying used CNC electronics is an affordable option for some people. You can save nearly 50% or more on some equipment. Be careful when buying used, you want to be sure the equipment is in good condition.

A better option is to look for refurbished equipment. These machines have been inspected at the factory. Any broken or damaged components are replaced. In many cases, the machine is painted and new decals are applied. It?s like getting a new machine for a significantly reduced price. Often, you will get a one year warranty with reconditioned equipment. This gives you time to be sure it is working properly and if not, you can get it fixed for free. Charles Mahoney publishes many articles for the website http://www.inside-woodworking.com . He writes on topics from CNC technologies and other areas in this field.