Wednesday, May 19, 2010

Pre-raquisite Software Skill for operating the BEAST

Building the CNC Router was a stressful but fulfilling experience. Inflated ego was the direct product of this memorable journey. BUT that is only the starting line of my CNC endeavour. Now that I have a machine at my disposal, I need to learn up how to drive this machine to churn out those beautiful artifact like we seen in the net.

In retrospect, running the machine is easy, but that is only after you actually operate the machine...

I totally over estimated my learning capacity, & underestimated the complexity of the software involvement in running a CNC machine. After over a month of tinkering with running the machine & many software packages, I come to this overly generalised summery.
You need a Drawing to convert to G-code, feed the G-code to the Motion Controller. To cut properly, one need to know the cutting tool characteristics, material properties & some machining procedure knowledge.

To make something with or without CNC machines, we need to provide specific specifications of what to do, so coming up with a drawing is the first step.
From my understanding, we can use 2 types of drawing files, namely Raster & Vector.
In raster, examples are bitmap such as jpg, png etc. With this, the cutter will transverse the whole area covered by the file, this is how most 3D cutting is done. With Vector file, the cutter only travels along the path where the cutting is required, saving lots of time. this is how profile cutting & 2.5D are done.

Drawing software
With different cutting strategies different software are used. In vector files, we direct the cutter in straight lines to cut the profile or contours, leaving the other space alone. In raster file, the cutter will transverse every mm of the file... example of raster files are bitmap. & the generally accepted vector file format is .DXF, other formats are SVG, AI, STL... etc etc
I'm fortunate enough to have worked with AutoCad in my junior career life & residue memory helps a lot when relearning. This is my preference for 2D & 3D rendering but there are others such as SolidWorks. You can also use CoralDraw, Win Paint, Adobe Inventor, SketchUp Pro,.... Open source CAD drawing are not quite up to the fee software but I find Blender is a promising, still crude but its getting somewhere.
I also learn that one doesn't need to draw a drawing from scratch everytime, especially when we are dealing with ornamental & art craft... We can "convert" raster files to vector files by tracing bitmap. I downloaded the open source INKSCAPE software which can do many capabilities of fee software such as the Coraldraw & Adobe AI.

One can write G-code from scratch if they feel they are up to it, BUT I'm too lazy for that... CAMBAM, UCANCAM, SHEETCAM, LAZYCAM... a whole library of CAM software which can translate vector file into G-code. I evenetually ended up with VCarve Pro for 2D & 2.5D works & Cut3D for 3D works..

At the end of the day, depending on requirement, all common or not so common software packages works, the difference are in the learning curve & the ingenuity of the user to utilise the available capabilities of each. Its a compromise of $, time & requirement.

No comments:

Post a Comment