Download and Install Ruby

You need to have downloaded and installed the Ruby interpreter from Ruby Windows installer or Linux users can get it from the Ruby Download page Most Linux distributions include Ruby by default.

For windows users Ruby is pretty much a standard install. For Linux users it must be built but this is a pretty easy step and if you have already built EMC2 then all the tools are already present.

For those who are not aware of Ruby it is a powerful scripting language that competes in the same space as Python and Perl. It was invented after both Python and Perl and it is more heavily influenced by Smalltalk and Simula which means that it is more of a True Object Oriented language. No programming language is perfect but Ruby is pretty nice and Python programmers can make the switch quickly. It is also easy for Visual Basic programmers to use. Even non programmers can use it for scripting quickly and easily.

Download and Unzip the cncutil.org CNC Utility Library

The CNCUtil library is composed of a series of Ruby script files which must be present on your computer before you can use them. You can download the cncutil.org CNC Utility Library from http://cncutil.org/download We are extending this library on a daily basis so you may want to stop back and download new versions periodically.

If you are using windows XP or Linux then the utility to unzip it is built in. If you are using older windows systems you will need a unzip tool such as Stuffit expander which can be obtained free from http://www.stuffit.com/win/expander/

• Notepad++ A high speed 32 bit text editor with ruby color syntax only runs on windows. Runs well on 64 bit vista and Windows 7
• The Crimson editor is fast, free provides the feature of tabs across the top like Visual Studio. It is not fully ruby syntax aware but it auto detects the language features and provides OK but not exceptional syntax coloring. One of these days I will make a ruby syntax file to improve it's coloring.
• Edit Plus A shareware editor that I have been using for years mostly due to it's simple syntax file. The version I am using does not have the tabs across the top which I really miss. optional download syntax file

Running the Programs

The ruby programs are all ran from either the Linux or the windows command prompt. If you are using Linux then you probably already know how to use shell windows. If you are using windows then you will find it under Start, Programs, Accessories or alternatively you can use START, RUN and type in CMD. Once you start the command console you should get a window that looks something like the following window.

The DOS command prompt is left over from the early micro computer days and in 1982 my first PC only had the command prompt and everything was done using it. The Graphic user interface provided by windows has eliminated much of the need for the command prompt so that many windows users don't even know it exists. I still find it helpful for many tasks and in a lot of situations I can do stuff faster from the command line than I can from windows

Once you have a command prompt running, The first thing you have to do is change to where you have the CNCUtil library stored which is also the same place you will save your scripts at least while you are getting started. On my machine that is on my C: drive in the \CNCUtil sub directory. You change directories as shown the next window.

Now you can run any of the programs stored in that directory. You can see a list of the available ruby programs by using the command DIR *.rb. You would normally only want to see part of them so you can filter this list with part of the name such as DIR *test*.rb as is shown in the next picture.

You run the ruby programs by typing ruby filename.rb as shown in the picture below which is running the program "test_rect.rb" which happens to be one of our examples which mills out pocket rectangles. The .rb extension is a convention since all ruby scripts end with .rb by convention.

You will notice that Ruby starts showing the GCODE on the console window which doesn't do us much good since we need to save it in a file that can be ran by our CNC driver such as EMC2. As it turns out both Linux and DOS use the same convention for saving the contents results of a run into a file. You use the same command ruby test_rect.rb but this time we add "> test_output.ngc" which will save the results in the file test_output.ngc as shown in the next picture. Note the .ngc file extension is what EMC2 expects by default but other CNC drivers use different extensions.
You can change the output name to any valid dos file name but we recomend that you avoid all punctuation other than - and avoid all spaces. The same thing applies to new programs that you may write.

Now that you have the output GCODE file stored such as we did in "test_output.ngc" the next step is to open up in the GCODE emulator and and run it as shown in the next picture. One important step is to make sure you tell the emulator how large your source material will be and to configure your bits for the correct diameter. My emulator defaults to 100 x 100 inches which is pretty much worthless for showing the 3 inch parts I normally work on.

I normally do everything above on my windows machine and then transer the .ngc files over to my Linux machine to run through EMC2 but sometimes I will do it all on my Linux machine. One of the great things about EMC2 is that it runs on Linux which has plenty of power left over to run a variety of nice editors and web browsers.

If you are doing a lot of editing it is worth looking into using CVS to keep track of your ruby source code and ngc files. CVS not only provides a good way to keep track of versions of your programs but it also makes it very easy to keep multiple computers up to date with the lattest versions of the programs. The CVS client and server is free on Linux so the EMC2 box can also perform this function. The CVS client is free on windows.