Big  Blue Saw


General Updates

Getting started is often the hardest part of creating a design for a custom part. I often have customers come to me looking for a particular mechanical part that they just want tweaked a little bit. I often tell them that their best bet is to find a CAD file that's similar to what they need, and make the changes that they require. My two favorite resources for CAD files for mechanical parts are McMaster-Carr and SDP/SI. In this article, I will show you how to use these incredible free resources to jump start your project.


SDI/SI is one of my favorite sources for parts for my robots. They sell a variety of mechanical drive components including bearings, gears, pulleys, and the like. Their online catalog also lets you download CAD files in a variety of formats for almost everything that they sell. From their home page, you can click the "BUY ONLINE" tab to get to their online store where the CAD drawings are located.


For example, let's suppose we want find the CAD drawing of a gear. Their online shop has an expandable list of items that they have for sale. First we can click on "Gears" to see the different types of gear.


Then under "Spur Gears", we can select "Metal".


On the right hand pane, a list of all the metal spur gears will appear. We can click on the part number to show the details of that item.


The product details will appear in a new window. There's a link that says "AutoCAD Drawing", but this link didn't work for me. However, I was able to get the drawing via the "3D CAD Models" link.


SDP/SI wants you to register before they will let you download any CAD files. You can use your existing SDP/SI login or click the "Click here" link to create a new account. The new user registration page (not shown) is easy to fill out and doesn't require you to jump through any hoops like a confirmation e-mail before allowing you access to the CAD models.


After you register, clicking the "3D CAD Models" link will now show you a download page like the one shown below. Before you download, you need to set the file format in the drop down list, as well as any dynamic attributes for the part.


For most of my CAD work involving waterjet or laser cutting, a simple 2D DXF file is quite sufficient to model my final parts. This is one of the formats that SDP/SI can provide.


SDP/SI can provide a simplified drawings using the "Dynamic Attributes" feature. This may help with rendering performance in your CAD tool. In this case, I want to get a model of the whole gear, so I enter 8 teeth for the "# of Teeth to Display on CAD Model".


After clicking the "Download 3D Model" button, the web page will indicate that the CAD model is being generated. When it is done, you will see a link that lets you download the CAD drawing. When you click the link, your web browser will begin downloading a ZIP archive file containing the CAD drawing.


Here's what the downloaded file looks like in QCad.



Mc-Master-Carr is legendary among makers. They carry nearly half a million products of every sort, including nuts and bolts, raw materials, hydraulic components, cleaning supplies, and tools, just to name a few things. If you haven't seen their website yet, take a look.


Their website does a good job helping you sort through the giant variety of stuff that they sell, but getting to a particular part might mean selecting 5 or 6 different parameters. For instance, for machine screws, you have to choose the material, head type, thread size, length, and so on. I'll spare you all of that and just choose a particular screw with McMaster-Carr part number 91241A083. To get to this part on the McMaster-Carr website, just enter the part number in the search box on the home page and click "Find".


This will bring up the product detail page for the part, a type of socket head cap screw. You will notice that this page has a link on the left-hand side for a "Technical Drawing". (Note: this link will not be present if McMaster-Carr doesn't have a CAD drawing for the item).


Clicking on the "Technical Drawing" link brings up a measured drawing in your browser. This is nice, but not quite a useful as a CAD file. You can click the "DOWNLOAD" link at the top of the page to select a CAD format file to download.


In this case, I want a 2D DXF file, so I will select that and click the "SAVE" button. This starts the download process.


Here is the drawing from McMaster-Carr as shown in QCad.


In this podcast, Big Blue Saw interviews Clay Benning of the Alliance Theatre in Atlanta, Georgia. Clay is a sound designer and recently worked with Big Blue Saw to build a portable sound console. In this interview he talks about his background and the experience of working with Big Blue Saw.

Listen to the MP3.

Clay says:

I was very pleased with the say everything came out. I think the anodizing... worked very well and really gives it a nice look to it. I was very happy with the waterjet cutting... I've seen the pre-manufactured ones that you can get from the manufacturer and I think [the custom waterjet brackets] hold up just as well.

I will be competing at Robot Battles on Monday, September 6, 2010 (Labor Day). The event will be held at Dragon*Con in the Hyatt hotel in downtown Atlanta, GA.

This is my robot for the event. It is called "Big Blue Saw Presents Jaws".


The custom parts on Jaws are made using Big Blue Saw's laser cutting, laser engraving, and waterjet cutting services. This includes the frame, the aluminum weapon gears, the gearbox, and the weapon forks.

Video of the machine in action.

Big Blue Saw's DXF Export For Inkscape

At Big Blue Saw, we get files from our customers in a variety or formats: from AI to ZIP. Our online quoting system and waterjet cutting machines really work best with DXF format files, though. Inkscape, the open source vector graphics editor has proven extremely useful in dealing with a variety of file types.

Ready to turn your DXF designs into real parts made from aluminum, stainless steel, or other materials? Try Big Blue Saw's online quoting and ordering system.

This Big Blue Saw DXF Export for Inkscape is based on Better DXF Export and Better Better DXF Export.

It has the following additional features:

  • Fixed Python version incompatibility crash on Linux.
  • Inches supported as the measurement units.
  • Curves are converted to smaller, more accurate line segments. This improves the final part quality.
  • Color output was supported.
  • Layer names have spaces converted to underscore for improved compatibility.
  • It has been tested on Linux as well as Windows.


To install:

On Linux or Windows:

  1. Close all open Inkscape windows.
  2. Download the ZIP file containing Big Blue Saw's DXF Export For Inkscape using the link at the bottom of this article.
  3. Unpack the ZIP file into your Inkscape extensions directory: typically C:\Program Files\Inkscape\share\extensions on Windows or /usr/share/inkscape/extensions on Linux. You will need to overwrite the file with the version included in the ZIP archive.
  4. Restart Inkscape.

  5. Hints for the Macintosh platform, courtesy of John Markham:

    The extensions folder is: /Applications/

    A dependency will be noted when attempting to save as DXF the first time:

    "The fantastic lxml wrapper for libxml2 is required by and therefore this extension. Please download and install the latest version from, or install it through your package manager by a command like: sudo apt-get install python-lxml"

    Which can be installed with pip.

To use after you've installed Blue Saw's DXF Export For Inkscape:

  1. Create your drawing as normal.
  2. Ungroup all items by selecting everything (Ctrl-A or Edit | Select All from the menu) and then ungrouping repeatedly (Shift-Ctrl-G or Object | Ungroup) until all groups are broken apart.
  3. Convert all objects to paths. You can do this items by selecting everything (Ctrl-A or Edit | Select All from the menu) and then pressing Shift-Ctrl-C or choosing Path | Object to Path from the menu.
  4. Choose File | Save As from the menu. In the dialog box that appears, choose "Big Blue Saw DXF Output" and click the Save button.



One more thing, for those reading this far. Most of the time when I, personally, want to get a DXF from a file loaded in Inkscape, I save it as an EPS, and convert to DXF using the pstoedit package. This preserves splines and curves, which is nice, but requires the use of a command-line tool, which isn't for everyone.

More information on using Inkscape with Big Blue Saw for laser or waterjet cutting. Turn your Inkscape drawings into real metal or plastic parts. Big Blue Saw offers instant quotes from your DXF file!

Ready to turn your Inkscape designs into real parts made of metal, plastic, or other materials? Sign up for our FREE e-mail course.

Learn about:

  • The easiest way to order parts based on your Inkscape designs
  • What kinds of metals and plastics to use in your project
  • Getting the best prices on waterjet and laser cutting

Update 0.2: Bug fix based upon report from commenter blackfox. Download the new version of Big Blue Saw's DXF Export For Inkscape Here.

Let Big Blue Saw turn your Inkscape designs into real parts made from aluminum, stainless steel, polycarbonate plastic, and more!

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