I am brand new to the use of g-code. I have my software and driver/steppers working. Building a cnc router and should have it ready in about a weeks work. I am looking for a g-code toutoral that teaches you proper ways to write it. I have found some that only give some of the code meanings. I am sure that most of my use of the router I will be inputing the code.  Is there a way to input more then one line of code at a time using Mach3? What does .TAP stand for? I also don't under stand I and J code. One more, will I have to use an editor program and then save it as a .tap and then load the code or is there a shorter way to get the code in mach3? Thanks for any info Carl

Yeah, what he said.  
Really, for now, I'm content with downloading freebies. Later on I'll need some special projects that may require converting CAD to G-code. Ideally I would like to convert Google sketch-up drawings to G-code with a free or extremely cheap program.
If anyone knows of something like this, would it be something you could use Carl?

Oh, and welcome to the forum from another newbie.

CWEBS,

MACH assigns the file extension   .TAP  for it's Gcode files. 
You can use any text editor  to make or edit the file ( ie; notepad, wordpad)

For an understanding of I & J mode or ARCS in general, go to the Members Docs Thread as there is a tutorial on ARC
motion. Altgough it is for the Lathe it is still has a lot of info which will be of value to you. In Mach Mill you can click on the GCODE button and it will give you all the definitons of the various Gcodes.

As far as code goes there are some wizards that are available in Mach Mill which you can use to generate the code for machining something. Try some of them based on simple stuff / figures and take a look at the generated Gcode.
You will learn a lot. scroll thru each line and associate it to the code.

There are numerous sites that provide tutorials on writing gcode. I would strongly recomend one of the books by
Peter Smid. Google the name and you find some places where you can take a look at the contents. I think Amazon
is one.

I think there is a free version of CamBam available for download. LazyCam comes with Mach and you can try that out.You will need a Pro License for it's advanced features.

Welcome to the world of CNC.

RICH

Thank you Rich for the very helpfull information. I do use Google a lot and have found some help there. My question about the file extension TAP is what do the T,A and P letters stand for? Not that it realy makes any differance just would like to know.  Thanks again Carl

Hi, Carl

Mach3 can load 4 different type of file extensions, TAP, NC, TXT, NCC, These are common extensions used by various programs for G code format's and other programs for there own special use.

Hope this helps, Chip

BINGO! Now it falls together fo me. TAP refers to tape. Before retirement I ran a TNC machine.  I was a machinest starting in 1966. Back in the 90s the machine shop only had one CNC and one TNC. I ran the TNC along with the other machines. It is a large machine shop at the local ship yard. Thanks CHip

You already can go from sketchup to Gcode.  First download a ruby script called skptostl and put it in your ruby scripts folder of sketchup.  Draw a small 3d object that you would like to mill, highlight it, and launch the skptostl ruby script. The script will ask if you want to export the item or the entire drawing.  Choose the item.  You will then find that you have a .stl file of your object that exactly matches the dimensions, cuts, and shape of your original 3d drawing.  STL stands for Stereo Lithography and it is a common format used in 3D printing.  Next you search the web for Freemill and download it.  You will have to register with the company that provides it, but that's just so they can call you and offer their non-free product once your hooked on CNC.  This free program will accept a .stl file and convert it to gcode for Mach 3.

Yeah, what he said.   
Really, for now, I'm content with downloading freebies. Later on I'll need some special projects that may require converting CAD to G-code. Ideally I would like to convert Google sketch-up drawings to G-code with a free or extremely cheap program.
If anyone knows of something like this, would it be something you could use Carl?

Oh, and welcome to the forum from another newbie.