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Old 04-04-2015, 07:26 PM
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allessence allessence is offline
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Default What to learn for CNC programing?

Hi guys.. I am assuming This is a fairly hard question to answer.

But, I am interested in learning how to program CNC..

Where do I start.. basically a CNC Milling machine is the main interest..

The good the bad and of course..

If I defend myself I am attacked.

My meaningless thoughts are showing me a meaningless world.

My attack thoughts are attacking my invulnerability.

I'd like to think of something smart, but I don't want to hurt myself.

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Old 04-04-2015, 08:02 PM
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GWIZ GWIZ is offline
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Down load LinuxCNC. about 500MB
Run Shureline 3Axis_inch

It only runs with Linux Ubuntu 10.04 that comes with it.
I did not load the program on the computer but run it off the CD so I can not save things, best load it on a dedicated computer.

At least it ran for me without having the machine. its a good start.

Maybe this link.
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The factory of the future will have only two employees, a man and a dog. The man will be there to feed the dog. The dog will be there to keep the man from touching the equipment. ~Warren G. Bennis

Last edited by GWIZ; 04-04-2015 at 08:18 PM.
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Old 04-04-2015, 08:26 PM
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Lu47Dan Lu47Dan is offline
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I had looked at various CNC programs, I liked a few different ones. I actually programed on one that was what is called "Conversational" programing. It does away with having to understand G-Code. I do not remember the programs name.
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Old 04-04-2015, 08:44 PM
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LKeithR LKeithR is online now there a prize?
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CNC programming is a huge field; it's very complicated and, in general, it's not getting any simpler. I think the first question you need to answer is what machine--or family of machines--do you want to program? What level of programming do you want to reach? Do you want to program a small machine of your own for fun--and possibly a little profit? Or are you looking at this as a career step with a job as a programmer in your future?

G code is the base on which most programming languages are built. If you had anything to do with computers in the early years you might have run across what are called "assembler" programs. G code is similar in nature. On the one hand it's "relatively" simple because each line of code executes one single step in the program. On the other hand it can be quite complex because it can take "many" lines of code to complete one operation.

Probably the most common "developed" program is Fanuc which has become a bit of a standard. There are, however, many other languages and, when you throw in all the proprietary stuff that individual manufacturers have created there are a lot of things to consider...

Measure twice and cut once...or...wait, was that the other way around?
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Old 04-05-2015, 05:05 AM
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GWIZ GWIZ is offline
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In the olden days if you wanted to cut a circle you would have to input each X, Y increment movement say .001 until you completed the circle
that could end up with a thousand increments (lines) just to cut a circle.

There is more then one way to use a G code for cutting a circle
Just entering G02 J-1.0 F10.0, would cut a 2" circle 10 ipm.
The machine figures out the math for each X Y increment so you don't have too, also allows the operator to change the circle size without alot on math.

Using G codes for drilling allows you to drill a thousand equally spaced holes with one line of information.

Some pc programs CAM that make CNC machine programs don't output G codes very well And will increment each X Y movement, in that case you have to go back to the PC to make corrections and reload the new machine program.
The factory of the future will have only two employees, a man and a dog. The man will be there to feed the dog. The dog will be there to keep the man from touching the equipment. ~Warren G. Bennis
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Old 04-05-2015, 10:15 AM
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dubby dubby is offline
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Learning G-code is likely the best starting point, but you really don't start to grasp it well until you're well underway. It's not difficult to figure out the simple stuff, but there's lots of simple stuff that adds up to make it complex.

You can get programs that will do all the coding for you, more or less. You still have to understand the basic processes in milling and then learn how the computer guys have translated them. It took me/us about 3 months to get efficient enough with one program to be able to make the machine do anything. Each program is different and still has a pretty steep learning curve. I do wish that I could find a simple, effective, cheap program that'd translate drawings to toolpaths.

What kind of machine (brand) are you considering? That makes a huge difference in what will work, and the manufacturer may already have a package deal that includes everything you need--software wise--to get you going. I'm still trying to find the money to buy a Tormach PCNC1100. The price has gone up from about $26k to closer to $32k fully loaded out in the two years that I've been dreaming. But, it'd come with all new software which really wouldn't work on my existing machines. That means I'd have to go back and learn a whole new system, which means more time, and more knowledge about CNC as a whole.

I currently run the LinuxCNC and have pretty decent result on my little Sherline. It will allow you to use the machine manually through the keyboard, as well as G-code. It doesn't write anything for you, so you're back to that again.

My one, absolute warning about looking at CNC. You've probably already come across the ads for them by now if you've googled the process any. A company called BobCAD exists, and they will absolutely suck the soul from your once dream filled body and spit it out on the floor, and leave you with a wasted, empty wallet. Their program works, sort of, it's cheap initially, sort of, but they'll be back for more and their license agreement is harsh. If I could go back in time to do one thing over, it would have been to never click on their website link.
I've always had more time than money.

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Old 04-05-2015, 11:27 AM
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Roundrocktom Roundrocktom is offline
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To really get your feet wet, a super simple CNC machine (dremel tool / pen plotter) will work. Best if you can make it from as much scrap as possible (keep cost down). Even derlin bushings.

John over at NYC CNC did just that:

You then have something that can be driven by GCode. Idea is to learn the basics of G Code -- so you can move the plotter around.

You can download something like this (just grabbed at random)

For me until I actually could sit at the machine and start typing in line items
to move my machine... well, it was too boring! Start making something, and it is a lot more fun!


Snipped of some G-Code, video shows what it was doing (note snippet is just peck drilling.... made some 1" thick, video shows 1/2" thick 6061 being cut)

( Milling_Machine_Clamp_1_inch )
( File created: Sunday, March 23, 2014 - 01:13 PM)
( for Mach2/3 from Vectric )
( Material Size)
( X= 8.000, Y= 10.000, Z= 1.000)
(Toolpaths used in this file
(Drill 1)
(Profile 2)
(Tools used in this file: )
(1 = V-Bit {90 deg 0.25"} Merlin Carbide)
N140 (Tool: V-Bit {90 deg 0.25"} Merlin Carbide)
N170(Toolpath:- Drill 1)
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Old 04-05-2015, 12:44 PM
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Spend some time reading over on
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Old 04-05-2015, 03:34 PM
PixMan PixMan is offline
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I can teach you just about anything you need to know, from 2-axis conversational (which I have in my shop) to just shy of 5-axis milling.
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Old 04-05-2015, 03:43 PM
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Early 70's Go-Code:

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