Instructions
operations like milling a large round part or drilling circular hole patterns easier to
program. It also allows you to do operations like milling threads or helical gears that
would not be possible without CNC because a rotary axis and a linear axis must move at
the same time and in the proper relationship to each other to create the desired tool path.
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Part 2
Programming Sherline CNC Machines
with EMC2
Although there is quite a bit of well-written instruction on how to program on the Linux
CNC site, I believe you should only go there to learn beyond the limits of my
instructions. Having too many instructors on a subject that you know nothing about isn’t
a good idea at this time. At the end of my instructions there are lists of the many words
and commands available to you taken from the Linux/EMC site; however, there’s no
reason to remember them now. I want you to learn them as you use them. The commands
and words that I’ll be using are so basic to writing code that they’ll soon become a new
language.
UPDATE —July, 2005: Note: I recently went back to the EMC website at
http://www.linuxcnc.org/ and was very pleased to find many improvements have been
made since I first wrote these instructions. It’s much better organized now, and I believe
after you get the basic concepts from my instructions about how CNC g-codes work, it
would be to your advantage to go there and learn about the addition of the many canned
cycles that are now available to EMC users. A complete list of g-codes is included in the
Ubuntu version of Linux (2009) and can be found under Applications>CNC in the main
menu or at www.sherline.com/gcode.htm . I take my hat off to the EMC group for
making these much needed improvements.
Print a copy of these instructions
Although you could jump between the control screen on your monitor and the
instructions, it would be a cumbersome way to work. You can print a copy of these
instructions from the CD using any computer with a printer hooked up to it, or you can
print a copy from your Linux computer by unplugging the servo driver connector from
the parallel port and plugging in a printer instead. In fact, most printers can now be
plugged into the USB port in the front of the computer.
To make it easier and to save paper, we have saved just the portion of the instructions that
refers to the programming as a separate file you can print out. You have your choice of
formats: They are called CNCprint.doc (MS Word) or CNCprint.pdf (Adobe Acrobat
Reader). You can also open the instructions on Sherline’s website at
www.sherline.com/CNCinstructions.htm and print only the pages starting at the
beginning of Part 2. (Note: Later editions of these files may include a version number in
the name; for example, CNCprint5.pdf.)
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