Parent Category: Big Blue Saw Blog
Created: Wednesday, 12 October 2016 18:38
Written by Simon Arthur
"You have areas inside the part which cross each other."
You may have seen this error when uploading a design to Big Blue Saw's online quoting system. Let's take a closer look at what this error means and how we can correct the problem.
This message indicates that the online quoting system is able to find the outside outline of the part, but you have holes or other features within that outline that cross over each other.
If you're just beginning with Big Blue Saw, it's important to understand two things:
1. What kinds of parts you can make with Big Blue Saw. We can make parts using waterjet cutting or laser cutting. This means that all parts are cut from flat stock. The flat stock is cut completely through on every pass of the laser or waterjet.
2. Your uploaded design should contain only the outline of the part to be made, scaled 1:1. Read our guide to formatting CAD files.
With those 2 basics in mind, read on for help diagnosing and correcting common mistakes.
Where to click to get a diagnostic view.
When you get an error when uploading a design, you should begin diagnosing the problem by clicking the link for the Diagnostic View of the part. This will show incomplete lines and highlight problem areas.
If you haven't already, review the DXF or DWG file in software which is specifically intended for working with these files, like DraftSight, LibreCAD or QCAD. We have a list of free and low cost software for working with DXF files. Sometimes when you export from an application which is not specifically designed for DXF files, the export won't be completely clean. Zoom in on the areas where the online quoting system finds a problem. Sometimes you will need to zoom in quite closely to find the mistake.
Here are 5 common causes of the error "You have areas inside the part which cross each other."
1. The line in the drawing was intended as a cut line, not the outline of a part.
Drawing of a puzzle with common cut lines.
Box for laser cutting with common cut lines.
This is often the case for jigsaw puzzles and designs with pieces intended to fit together after laser cutting. Every part should be outlined individually to work with the online quoting system.
It can sometimes be practical for us to do this type of cut. Contact us if you really need this type of waterjet or laser cutting.
2. You have duplicate overlapping lines due to a 3D projection error.
3D part incorrectly projected into 2D
If you have created the original drawing with a 3D drawing tool (SolidWorks, Sketchup, OnShape, etc.), make sure that your export to a 2D drawing does not include any hidden lines. The drawing used with Big Blue Saw should be a single outline of the face to be cut.
Often lines from a 3D projection will be closely overlapped and may be hard to see without zooming in closely. You may have to try selecting lines and deleting them to find closely overlapped lines.
3. You have duplicate overlapping lines due to a stroke path.
Outline from a doubled stroke path.
When using a vector based illustration tool like Illustrator, Corel Draw, or Inkscape, make sure that the export procedure you used exports a single line for the outline of your part. These tools can sometimes export a stroked path as two separate lines: the inside of the stroked shape, and the outside of the stroked shape.
View the drawing in outline mode (View | Display Mode | Outline in Inkscape or View | Outline in Illustrator) to see the outlines which make up the shape.
Normal view on left in Inkscape of a shape with a complex stroke path, outline view on right.
Delete any outlines other than the ones which show the exact outside outline of your parts. Remove any lines or paths which cross over other lines or paths.
4. You have visible objects in the drawing which were not merged correctly.
Outline view of a part with incorrectly merged holes.
Like #4, this problem is also commonly seen when using drawing applications like Illustrator, Corel Draw, or Inkscape. You have multiple objects in your drawing which appear to be the a single object because they overlap and are the same color.
Again, view the drawing in outline mode (View | Display Mode | Outline in Inkscape or View | Outline in Illustrator) to see the outlines of the shapes in the drawing. Merging the shapes before exporting should fix this problem.
Normal view (left) and outline view (right) of a part with incorrectly merged holes.
5. Your drawing includes a sheet format or information other than the outline of the part to be cut.
Some CAD software will create a grid for you to enter information about the creator of the file, date, material, and so forth. The solution here is to delete everything in the drawing other than the outline of the part to be cut.
If you have gone through all of these steps and still can't find the problem with your file, please contact us and we'll do what we can to get your design working.