Overview


To get the best results out of the FabLight machine, we recommend you use a CAD program to create .dxf (or .dwg) files that are imported into FabCreator. If you are using Adobe Illustrator, there is a 3rd-party plugin available (Windows only) that may “clean up” your geometry for better performance on the machine. The plugin costs $29 and there is a free trial available to see if it meets your needs before you purchase. The demo version is available at this link: http://illustrator.e-cut.ru/index.php?view=article&id=58


Disclaimer

The plugin is meant to convert geometry to arcs. It may or may not be effective with highly complex Illustrator files made of splines. 3D Fab Light does not support or maintain this plugin, but we are offering information here for the benefit of users that work in Illustrator.


Why use a plugin?


CAD programs can create files with arcs. Other drawing programs, such as Adobe Illustrator, do not support arcs and mostly use splines, which are converted into polylines in FabCreator. When the machine moves through an arc, it slows down depending on how small the radius of the arc is. This speed control is not available for polylines. At high feed rates, this can lead to irregular motion.


Using the eCut CNC plugin


There is a free trial for the plugin available at this link: http://illustrator.e-cut.ru/index.php?view=article&id=58


Scroll down to the “eCUT CNC” Demo version link. There are a few different versions available, each for a different version of Adobe Illustrator.


Installation instructions: http://illustrator.e-cut.ru/index.php?view=article&id=68


Usage instructions: http://illustrator.e-cut.ru/index.php?view=function&functionid=46


The basic instructions are to select all geometry, then go into the Effects menu. Select eCut at the bottom, and click DXF export. A window will pop up as shown below. Press the Parameters button.



The parameters button opens up more export options.



We have found that POLYLINE (Lines + ARCs) must be selected. Keep the ARC and LINE fitting tolerance between 0.002in and 0.0004in. You can experiment with these options as necessary. Press the “Export” button to open up a Save dialog and save your dxf file.


After you have verified the plugin works for your file, you can purchase the full version of the plugin at the following link for $29: http://illustrator.e-cut.ru/index.php?view=article&id=59


In more detail...


To understand why a plugin is needed to “clean up” Illustrator files, we need to talk about the geometry that makes up your .dxf drawing file. DXF files are made up of different geometry primitives, such as lines, arcs, and splines.


Lines are straight line segments. There are two endpoints.

Arcs are portions of a circle. There are two endpoints, a center point, and a “bulge” that can change the radius.

Splines are complex curves described by a mathematical equation. There are many control points.


Currently, the FabLight machine does not support splines; FabCreator splits up splines into straight line segments, called polylines. However, if the DXF file has arcs, the machine will recognize these and slow down around them if they are a small radius.


To see why using arcs is important, let’s take a look at a simple file, a rounded corner. In this file, there is a straight line, an arc, and another straight line. In this case, the machine will move at full speed through the straight line, slow down around the corner, and then move at full speed through the second line.



If this same file was made with a spline or polyline of small lines, the arc is no longer smooth. It would be converted into many small line segments (a polyline). The machine would move at full speed through the first line, attempt to move at full speed through each of the small line segments, and then move at full speed through the last longer line. Moving at full speed through each of these straight lines would cause jittery motion because the machine accelerates and decelerates at each of the points.



You can think of this similar to driving a car at 70mph around a bend. You would want to slow down to go around the corner in order to stay in your lane. Slowing down is only possible if you are able to look ahead and see the curve. With a series of line segments making up an arc (or other fine detail), the machine does not look ahead and realize it is moving along a curve. However, if the geometry is a true arc, then the machine recognizes it and slows down depending on how small the radius is.