What exactly is CNC programming?

fando

I would like to learn to 'operate' CNC machines. But what exactly 'programming' of CNCs consist of? Isn't it like you have a model done in CAD and than its automatically translated into G-code? Or maybe the process differ on different machines ('by hand' input of the code etc)?

I am unemployed now, and I thought I would start from the bottom up, doing an internship/course in machine tool operating. Then eventually progress to machine setting/CNC programming. Is this a good path or would I need engineering degree somewhere along?

CatFromHue

I've never done it but try looking on Google Books for CNC, you mightn't get the full book but enough to give you an introduction. Wikipedia is also handy for things like this.

http://books.google.ie/books?id=JNnQ8r5merMC&printsec=frontcover&dq=CNC+programming&hl=en&sa=X&ei=ZftYT7i-JsfO8QOig-jsDg&ved=0CEgQ6AEwAA#v=onepage&q=CNC%20programming&f=false

http://en.wikipedia.org/wiki/CNC

Turbulent Bill

fando wrote: »

I would like to learn to 'operate' CNC machines. But what exactly 'programming' of CNCs consist of? Isn't it like you have a model done in CAD and than its automatically translated into G-code? Or maybe the process differ on different machines ('by hand' input of the code etc)?

I am unemployed now, and I thought I would start from the bottom up, doing an internship/course in machine tool operating. Then eventually progress to machine setting/CNC programming. Is this a good path or would I need engineering degree somewhere along?

CNC covers the whole spectrum of automation, from line-by-line input of code (basically an automated version of manual machining) right through to fully-automatic part creation of parts. In my (very limited) experience of CNC there's always some level of manual intervention to check/correct paths etc. before production starts. It also helps a lot if the designer has an understanding of the machining process, so the part is manufacturable.

In general I'd advise going for the highest qualification you can get, but there are many degree-holding engineers out of work at the moment - you'd be joining a long queue for jobs. No harm starting a basic course in machining and seeing if you like it.

Stained Class

Turbulent Bill wrote: »

CNC covers the whole spectrum of automation, from line-by-line input of code (basically an automated version of manual machining) right through to fully-automatic part creation of parts. In my (very limited) experience of CNC there's always some level of manual intervention to check/correct paths etc. before production starts. It also helps a lot if the designer has an understanding of the machining process, so the part is manufacturable.

That's a good description of it alright.

Non-CNC machines require buttons to be pressed or levers to be pulled for them to operate.

CNC machines operate by reading a program called Computer Numerical Code, hence CNC.



M codes are direct functions.

i.e. M8/M9 are coolant on/off
M3/4/5 are spindle forward/reverse/stop

G codes are preparitary functions. They prepare the machine to perform a specific machining function.

i.e. G76:thread cutting,G32 tapping,G71 turning cycle,etc

X,Y,Z are used for positioning tools.

A lathe will have 2 axes, X & Z, whereas a milling machine will have 3 axes, X,Y & Z.
The Z axis will follow the forward/reverse direction of the tool.

I always program using the keyboard & monitor on the machine.

In my experiance most CNC programmers tend to learn on the job, though there must be courses out there to learn about it .

EDIT; I think modern ZEUS books have a couple of pages in them dedicated to some of the more common codes, to give you an idea of it.

fando

Stained Class wrote: »

In my experiance most CNC programmers tend to learn on the job, (...).

Would they be familiar with Non-CNC machines prior to that, or not necessarily?

Stained Class

fando wrote: »

Would they be familiar with Non-CNC machines prior to that, or not necessarily?

These days, most production machines are CNC anyway, so not really.


In some places you can start off by operating a CNC machine by loading it pressing a button & unloading it.

This is the 'Green button man' phase.

Later on, if you show inititave & ask the right people the right questions, you will get to know how the system operates.

Then, you can start setting the machine for yourself.

Get good at it & you have a new skill & hopefully a payrise from your Boss.

fando

I used to work on flat-bed routers (signage business) and quite enjoyed the whole process involved. But that was rather straightforward, CAM software was doing the complicated bit. Now, while on the dole with time on my hands, I thought to up-skill.
Thanks for the info.

Stained Class

fando wrote: »

I used to work on flat-bed routers (signage business) and quite enjoyed the whole process involved. But that was rather straightforward, CAM software was doing the complicated bit. Now, while on the dole with time on my hands, I thought to up-skill.
Thanks for the info.

No prob.

I'm sure there's some good CNC courses out there to give you a head start.

I learned on the job, so I didn't do any courses on them at all really.

It's not rocket science TBH.

Even if you don't get employment locally thru it, it's a skill that travels well.

Good money to be made in the UK or the Continent if you're a capable CNC setter.

ZRelation

Stained Class wrote: »

These days, most production machines are CNC anyway, so not really.


In some places you can start off by operating a CNC machine by loading it pressing a button & unloading it.

This is the 'Green button man' phase.

Later on, if you show inititave & ask the right people the right questions, you will get to know how the system operates.

Then, you can start setting the machine for yourself.

Get good at it & you have a new skill & hopefully a payrise from your Boss.

I would have had a very similar experience to this. Day 1 starting out, press button, make part, check dimensions. After a while this moved to changing tool offsets etc. and then adding simple lines of code. Never stayed long enough to code up any full runs (was a part-time job to get through college) but that was the general progression for guys working there.

Stained Class

ZRelation wrote: »

I would have had a very similar experience to this. Day 1 starting out, press button, make part, check dimensions. After a while this moved to changing tool offsets etc. and then adding simple lines of code. Never stayed long enough to code up any full runs (was a part-time job to get through college) but that was the general progression for guys working there.

CNC programming is not Rocket Science, as I said before.

At the same time though, I know plenty of guys who've been working these machines for 20+ years & still don't know how to program them.

It's a skill that's more valuble in other countries though.

Ireland, unfortunately doesn't have an engineering heritage in the same way as Germany or the UK.


CNC manufacturing would have been the way to go here, but unfortunately the people calling the shots had their minds on other things, like how to get as much Brown Envelopes into their pockets as possible.:rolleyes:

Turbulent Bill

Stained Class wrote: »

CNC programming is not Rocket Science, as I said before.

At the same time though, I know plenty of guys who've been working these machines for 20+ years & still don't know how to program them.

I think the master-apprentice way of learning CNC is very long-winded; as you mentioned it's not that complicated. You definitely need someone with experience to demonstrate the basics, and your own knowledge of machining, engineering, GD&T etc., but it's not a craft in the way manual machining is.

For anyone starting from scratch I'd recommend combining CNC with lead manufacturing techniques or other efficiency approaches. From my experience machining companies have a huge focus on efficiency, waste reduction, increased throughput etc. - just making the items isn't enough. Anyone with good CNC skills and the knowledge to use them best would do much better than a basic machinist.

dave2pvd

To be a CNC operator may not be a huge challenge, but to be a qualified machinist is.

In the industry I work in, we have both types of individual.

The machinists are able to operate manual machines such as lathes and mills. They can also set up and manually program CNC lathes and mills. Some can create and/or modify basic SolidWorks models.

CNC operators generally load and unload CNC machines. Experienced operators may also do some set-up work.

Generally, you need an operator if you're making 100s or 1,000s or more; you need a machinist if you're making lower volume production runs.

Machinists get paid a lot more than operators.

Pall

Are any CNC operators / machinists on boards.ie?