Archive for October 4th, 2008

My personal CNC tale

Saturday, October 4th, 2008

cnc programming

One day I knew I had a problem.  I just spent 4 hours with my plasma cutter in my right hand.  I had been cutting out patterns I had traced onto a sheet of metal.These interesting shapes were going to become my coffee table.  Everyone complained to me that I didn’t have a coffee table.  I thought, “I’ll show them” and began to build one.
Why make a coffee table out of metal you ask?  The quick answer is that I wasn’t much of a woodworker at the time.  On the other hand, I used to weld professionally and knew I could make anything out of metal.  That is how it all began, making a coffee table out of metal.

Now if you knew me, you know that I can’t just make something normal.  My brain is the scheming type that has to do things differently then the norm.  I wanted to make a table that would knock people’s socks off.  I thought a funky looking table, made out of metal, with casters and lights would do the trick.  You know what?  It did. 
I really had a ball making this table.  I mean I had serious fun.  So much so that I started to design others.  I began showing photos of my work to everyone I knew.  On top of that, I was getting good feedback.I just came across a new hobby, it was furniture making.  Who would have ever thought I would pick up furniture making as a hobby.

While making this first table a problem arose.  It is the one I mentioned above with my right hand.After cutting out all those parts my wrist really began to hurt.  While welding professionally there was always the threat of Carpal Tunnel Syndrome.Human welders are continually afflicted by this injury and others because of repetitive motion tasks.
If you repeat something over and over and over and over, your body gives out at some point.  After cutting up these table parts, I knew I couldn’t go on doing this for a hobby.  I knew something would have to change or the new hobby would break my body.

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how can I learn more about G-Code

Saturday, October 4th, 2008

learn cnc

In a word, no.  You will probably need to know how to quickly scan your G-Code if you are having problems during your machining simulation.  Other then that G-Code and a CNC program are throwaway programs for the most part.  What do I mean by that?  Let me explain.

Let’s look at a specific design.  Let’s say a 12” by 12” square.  You build your model, run it through your CAM Software and create a CNC Program made up of G-Code instructions to your machine.  Say tomorrow the job requirements change to a 24” by 24” square.  Do you go into your G-Code line by line and change the code?  Most people wouldn’t.  They would go back into their CAD or CAM program and scale the square up to 24” by 24”.Then postprocess the job to get their new CNC Program.

There are some people that would do this editing line by line because the design is simple.  Now think of a complex shape and what scaling it up or down would entail.This would include changes to the G-Code and reviewing it line by line.  We are talking thousands of lines here vs. going back and quickly scaling the model and spitting out some new G-Code.  And that is why G-Code is throwaway.  Use it over and over when you can, but don’t fret over archiving it if something changes.  It is much better to make a copy of the design (CAD File) in its original state and save that somewhere.  That is much more useful.

Post Processing??? - Now you have me worried.  With all the variations in G-Codes and M-Codes, how will I ever keep it straight?

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