Big  Blue Saw


Starting April 18, 2022, quoting and ordering will begin moving from Big Blue Saw to the Xometry website. You'll continue to be able to get fast service and instant quotes, in addition addition to a whole host of new materials and manufacturing processes!

General Updates

"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.

Diagnostic View

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.





CAD without CAD? No, it's not a Zen koan, it's maker.js, an open source project from Microsoft Garage that lets you create CAD designs by just tweaking a few settings. For example, the ring designer shown above lets you make rings or washers of any size by just entering an inner and outer diameter. Best of all, it outputs DXF files compatible with Big Blue Saw's online quoting system.

Here's another useful tool from maker.js: a sign creator with support for stencil fonts, rounded corners, and mounting holes.

There's also double pipe clamp builder. I'm told that this was inspired by the custom clamp from our articles on designing for waterjet.

Check out more things you can design on the maker.js demo page.

If you're ready to join two waterjet or laser cut parts together at 90 degrees to each other, you have a few good options.

Welding will work, but comes with its own difficulties, including the fact that it requires a welding machine and the skill to use it.

To join flat parts at right angles using only fasteners like nuts and bolts, read on.

The first technique is the t-nut techique, optionally using tab-and-slot for additional strength. Read more about it in our article on corner braces and the t-nut technique.

This technique can be done with common hardware store nuts and bolts. It occupies little space, except where the nut protrudes from the plate. The hardware is partially exposed, which can make assembly easier, but is less elegant looking than using nutstrip (described below) and leaves the hardware vulnerable to being bumped out of place.

Another popular option for joining plates at 90 degrees is to use nutstrip. This handy hardware is a square bar of aluminum with tapped holes at 90 degrees to make it easy to stick two parts together. You can cut it to length with a hacksaw to get just the right amount of hold.

One disadvantage of nutstrip is that it does occupy some space in the corners where your plates come together. On the other hand, it is very handy for lids and access panels, as you don't have to worry about the nutstrip falling out while you screw it in from the outside as it's held in place to the other panel. Read more about using nutstrip.

Got any other ideas for joining flat parts together at 90 degrees? Let us know!


From James T. Kilroy comes a video review of Big Blue Saw's waterjet cutting services. He uses Big Blue Saw to make custom panels for NEMA enclosures, among other things. In the video linked to below he talks about our services and shows you some of the parts he's made. His YouTube series Shop ADHD features discussions of a variety of machine shop and maker topics.

Mr. Kilroy also shared with us this lovely custom pulley he made a little while back with help from Big Blue Saw.

Ghost Robotics, one of our customers, has been in the news lately because of their Ghost Minitaur robot. What makes this robot special? It's the first first direct-drive, legged robot, and it's available for purchase!


Gavin Kenneally of Ghost Robotics told a little bit more about the Ghost Minitaur via e-mail:

The motors have custom motor drivers and a microcontroller to control them. The legs each work in a plane (2 degrees of freedom), but the body has a sprawl angle, so the left/right pair are not in the same plane.

There are lots of gaits that it can do, and this is ongoing work. So far, bound, pronk, trot, and crawl are possible.
You can see some of the details of the robot below, including waterjet cut parts from Big Blue Saw.

It can even open doors despite its small size.

The video shows more of Ghost Minitaur doing a variety of other tricks like jumping and climbing a fence!