In this getting started project, you’ll learn how to use Inkscape, a free graphics application, to turn a hand drawing, clipart, or typed text into an SVG file you can engrave onto an anodized aluminum dog tag, using the Bantam Tools Desktop PCB Milling Machine. This project requires very little setup and milling time to achieve a finished product. Though we’re using Inkscape, if you have access to Adobe Illustrator, you can use a similar workflow.

Tools

• Bantam Tools Desktop PCB Milling Machine
• Computer with Bantam Tools Desktop PCB Milling Machine Software installed
• Inkscape
• Metal engraving bit, 80°, 0.005"
• Scraper
• Digital calipers

Materials

• Dog tag, anodized aluminum

• High-strength, double-sided tape

Files

• Bantam Tools rooster SVG file
• Good vibes design SVG file
• SVG dog tag template for your own design 
• Printable PDF to draw your design by hand 

Step 1: Create your design. 

If you’re new to Inkscape, check out their online tutorials. And to learn more about the nuances of turning an image into a vector path, check out their tutorial on tracing bitmaps.

Note: You can use Illustrator to design and create SVG files as well. 

There are three ways you can create your artwork. 

1. Find clipart online.
2. Design in Inkscape.
3. Draw your design by hand.

After you’ve located or created your design, save the artwork to your computer.

Step 2: Lay out your design in Inkscape.  

Open Inkscape. It will automatically create a new document. When you save this document, Inkscape’s default is to save it as an SVG file, which is great since this is the file type we want.

Before you start designing, you’ll want to set your canvas dimensions. You can manually set them by going to File  > Document Properties, and in the Custom Size window, change the units to inches (in). Set the width to 1.950” and the height to 1.125”, and then save your file. 

If you’re still getting used to working in Inkscape but you want to start milling, we recommend using the dog tag template (linked above). Download the file and open it. The dog tag outline will be there, ready for your design.

Once you’ve set your dimensions or opened the template, it’s time to pull in your artwork. If you’re using a photo of a drawing or clipart, bring your design into Inkscape by clicking File > Import. Use the Select and Transform tool to select, move, and scale objects, and use the Text Tool to add text.

Note: The dog tag has a hole. Make sure your design isn’t located over this hole.

Step 3: Turn your bitmap design into a vector path. 

You’ll need to turn your bitmap design into vector paths so that the Desktop PCB Milling Machine will be able to mill it. To convert photos of drawings or clipart into paths, click on the image, then select Path > Trace Bitmap.

In the pop-up window, check the box next to Live Preview and adjust the Threshold settings until the design contains the level of detail you’d like. Click OK and close the window to continue designing. 

Using the Edit Paths By Nodes tool, click on the vector path to confirm it’s now a collection of vector paths. You should see lots of little gray squares that represent nodes of the vector. If you don’t see these little gray squares, something went wrong, and you should go back and try using the Trace Bitmap option again. The vector path you just created with the Trace Bitmap feature will now be in front of the original image. Delete the original image. 

If your design contains text that you made in Inkscape, like ours, you’ll need to convert it to vector paths as well.

1. Highlight the text.
2. Click Text > Put on Path.
3. Click Path > Object to Path.

Step 4: Fine-tune your layout. 

Adjust the size and layout of your design until you like the way it looks. To adjust the size, click on the Select & Transform tool (the black arrow), then click on one of the arrows that surround the object you want to shrink or enlarge. If you hold the control key, the proportions will stay locked as you change the object’s size.

Once you’re satisfied with the design, hit Save, and your SVG file is ready to mill. 

Step 5: Set up your job. 

We’re going to run through this job setup quickly. If you need more guidance on prepping your material, loading your tool, and entering information into the Bantam Tools Software, refer to the Light-Up PCB Badge project. 

1. Hook up the Desktop PCB Milling Machine and open Bantam Tools Desktop Milling Machine Software.
2. Home the mill.
3. Select “Metal Engraving Bit 80º” and then load the metal engraving tool with the bit fan attached.
4. In Fixturing, click Remove.
5. In the Material dropdown menu, select Generic.
6. Measure your dog tag, enter dimensions in the X, Y, and Z values under Material. Then put high-strength, double-sided tape on one side of the dog tag and place it onto the spoilboard so it aligns with the edge as shown here.

Step 6: Import your SVG file.

Under Plans, click Open Files and select the SVG file you saved in Inkscape. 
Our software will render the last saved version of the file, so if the preview doesn’t look quite right, go back to Inkscape and save the file again. Then refresh or reload the file into the software.

When your file is opened, both Engraving and Cutout will automatically be selected. Click Cutout to deselect it. Now only Engraving should be selected––this is exactly what you want!

Set the Engraving Depth to 0.003” and make sure “Metal Engraving Bit (80º)” is selected under tooling. Note the estimated mill time is about 18 minutes. If you’re okay with this time, continue setting up your file. If you’d like to create a custom tool for this project to optimize your mill time, click File > Tool Library > Add. We recommend the following speeds and feeds recipe:

• Feed Rate: 15 in
• Plunge Rate: 15 in 
• Spindle Speed: 18,000 RPM
• Stepover: 50%
• Pass Depth: 0.003 in 

If you set the canvas dimensions manually, you’ll need to change the Scale From value from Document Content to Document Bounds under Advanced in your file so that your SVG design will align the way it did in Inkscape. You’ll now see a box outline appear in the preview, which is the outline of the canvas from your Inkscape design file.


Note: Anything covered in red will not be milled. These warnings indicate that the end mill selected is too large to mill that area.

Step 7: Mill your design. 

When you’re happy with how everything looks, place all four windows on the mill and click Start Milling. Your final product should look something like this if you used the Bantam Tools rooster file. 

Troubleshooting

The mill engraved too deep or too shallow. 
Most of the time when errors occur in this project, it’s because the thickness (Z) measurement is off. Read more in our Setting Up Your Material guide to ensure you’re prepping the material and entering measurements correctly. You may also want to change the Engraving Depth value.

The mill cut a hole through my dog tag outside my design. If you didn’t deselect the Cutout option in Step 6, the mill will cut all the way through the material. 

The mill won’t machine my line. Lines can only be milled if they’re as wide as the width of your tool. The metal engraving bit you used has a cutting diameter of 0.005”, and therefore it can only mill lines that have a stroke of 0.005” or wider. If your line isn’t being milled, red markings will show up in the preview. To ensure the line is milled, either make the stroke wider in your design or use a smaller tool. Once you make this change, look at the preview again. If the stroke is now wide enough for the engraving tool to mill, there won’t be any red lines in the preview.