Customizing Sick of Beige cases for laser cutting

From DP

Jump to: navigation , search

Contents

Overview

Sob-cases-v1.jpg

Laser cut acrylic cases are super popular because they look cool, they're easy to customize, and cheap to make. This tutorial shows how customize our simple Sick of Beige case design to fit your own project. If you start with our standard PCB templates you can get your project into a case with minimal hassle.

Not everyone has a laser cutter, but there's cheap online services and your local hackerspace might have one. We'll show you what we do to order laser cut acrylic from Seeed Studio.

Before you start

You'll need to have Google SketchUp installed. See our introduction to SketchUp.

Download and install the SVG export plugin

We'll use Seeed Studio's laser cutting service, they take SVG formatted files. Grab the SVG plugin for SketchUp to save in this format. Put it in the SketchUp plugins directory.

Download the case template

Download the Sick of Beige simple case template SketchUp project that fits the standard size PCB you used.

Didn't use a standard PCB template for your project? It's gonna be a little more work, but you can still follow along.

Position the PCB footprint at Eagle coordinate center

SoB LC TUT coorC.jpg

Open the PCB file in Eagle, and the case template in SketchUp .

The origin marker of the standard size PCB footprint in Eagle should be positioned at the Eagle coordinate center. Origin markers are something every Eagle footprint has, it is identifiable as a white + marker.

We positioned our SketchUp Template so the coordinate centers in Eagle and SketchUp match. Any location on the board relative to the Eagle coordinate center is should match the template in SkectchUp. The intersection of Red, Green, and Blue guidelines shows the corresponding SketchUp center point.

Adding hole shapes for extruding parts

Find the part's origin point location relative to the coordinate center

SoB LC TUT grid.jpg

Next we find the origins of parts that need cuts in the acrylic. Keep in mind that the origin coordinates in Eagle are relative to Eagle's coordinate center.

First change the grid in Eagle to millimeters, found in the 'View/Grid' menu.

SoB LC TUT relcc.jpg

Right click on the component and select 'properties':

  • The 'Position' attribute is the origin's location. We will use these values to design the cuts in SketchUp
  • The left panel is the X-axis, while the right is the Y-axis

Using guide lines in SketchUp

SoB LC TUT guidce21.jpg

Once you have the location of the component draw guide lines in SketchUp.

  1. For X-axis click on the 'Tape Measure tool'
  2. Click on any point on the 'Green' coordinate line
  3. Drag the guideline to any point on the template and left click on that point

SoB LC TUT guide2.jpg

Now we'll precisely position the guideline to match the X-coordinate in Eagle using the keyboard input method.

  1. Right after you click on the point, type in the numbers of the X coordinate
  2. For example, if the location is 51.5mm from the coordinate center in the X axis, just type in '51.5' and hit 'Enter'
  3. The guideline will be positioned at exactly 51.5mm

SoB LC TUT guide3.jpg

Once you're done with the X-axis guideline it's time to draw the Y-axis guideline.

  1. Use a point on the 'RED' axis line as the starting point and then enter the Y axis value
  2. Now you have guidelines pinpointing the exact location of the components center on the template

Draw the hole shape for the part

SoB LC TUT hole.jpg

Once you have the part's origin location on your template, simply draw the outline of the hole you want to cut out.

Draw additional guidelines as needed, and refer to the component's datasheet for precise dimensions. Be sure to leave 0.5-1m of clearance for manufacturing defects.

Repeat for all extruding parts

Repeat the above for all the holes you'd like to cut out on your case. We use the 'Tape Measure tool' (guidelines) often. It simplifies the sketching, and fully control the location and dimension of the line.

The Tape Measure tool is really easy to use, and after a couple of minutes you'll be a pro. Here is a manual for the 'Tape Measure tool' if you need some more help.

Export the shape to the SVG file

SoB LC TUT expSVG1.jpg

Now that our case design is done, we'll export the files for the laser cutting service.

  1. Double click on the template. All lines and the face surface should be highlighted
  2. Right click on any highlighted area, and select 'Export to SVG file'

SoB LC TUT expSVG3.jpg

  1. The Export Plugin menu will open up
  2. Fill it in as shown above
  3. Replace the output file name with the one you want it to export to

Once everything is setup click 'Ok'. The plugin will let you know the file has been exported.

Send for Laser Cutting at Seeed

Sob-cases-v1.jpg

There's several online laser cutting services. Some have an online interface for ordering, others need time to prepare a quote.

We send our designs to Seeed Studio's cheap Laser cutting service. It starts at $7 total for 5 copies of a design. Seeed's low-cost international shipping saves us $50 or more over an order with our previous favorite supplier.

You can find further instructions at Seeed's laser cutting service page, but this is roughly what's involved:

Select the quantity, material, and the dimension options that suit your project.

For job difficulty, you need to estimate the overall length of the laser cutting lines. These include the template lines, as well as the hole lines. You can get specific parameters from SketchUp:

  1. Double click on the model
  2. Hold shift and click once over the highlighted area to deselect it, while keeping all the lines selected
  3. Right-click on any highlighted line and select 'Entity info'

Under 'Length' is the over all laser cutting length.

  • Below 600mm is Easy
  • 600mm to 1800mm is Normal
  • over 1800mm is Hard

Once you buy the cuts you will receive a order number. Compress your SVG file into an archive called L<order number>.rar (e.g. L123456.rar) and email it to Seeed.

Tip: If you're on a budget or making your first prototype, just send the top custom panel and use one of the extras for the bottom too.

Feel free to ask for help

Stuck on something? Ask us in the forum.

Share your designs

Case templates are open source and licensed under Creative Commons 0. They are free to use in any way you like, including commercial projects.

If you make something new please share your designs with us in the forum.