Cloisonné Enamelled Metal Trinkets (Otherplan Classic)
Note: This tutorial requires Otherplan Classic, OMC’s legacy application for Mac OS X.
Cloisonné is an ancient and venerable art. Traditionally, it involves meticulous placement of tiny strips of wire on a metal surface, creating gaps that are then filled with cut stone, enamel powder, or paint. Cloisonné can be used to enrich almost anything, but it’s most commonly used for jewelry, decorative art pieces, and small useful things like boxes and vases. The end result is always gorgeous. Here’s a way you can create cloisonné on the Othermill desktop CNC mill, from scratch, with just a trip to the hobby store and a few spare hours.
Step 1: Tools and Materials
- Computer with Otherplan Classic installed
- Inkscape or other image-editing software package able to produce .svg files. You can also just use the turkey and snowflake we used by downloading the .svg files attached to this step.
- Flat end mills, 1/16" and 1/32" End mills come in a variety of sizes, and if you’re making your own image you’ll want tools that best fit the project (more on that in a moment)
- Calipers for measuring
- Millable craft metal Brass, 6061 aluminum, and bronze work great and look beautiful.
- Enamel paint available in forms that dry on their own or that require baking to set. For this tutorial, we used the classic Testors model enamel paint. It dries on its own and is a time-tested quality product. You’ll need to use it in a well-ventilated area, preferably with gloves and a vapor mask.
- Toothpicks for applying the enamel
- Double-sided tape for sticking the metal to the Othermill’s machining bed
- Cloisonne.zip (contains both Turkey and Snowflake)
Step 2: Edit Your File
While Otherplan Classic will import an .svg file natively, you may have to tweak your image file a little to make sure it will mill the way you want it to.
- Edit your image so that there are discrete parts that can be engraved into your material to form nice channels. Otherplan Classic will cut anything that is a stroke or fill. In the case of the turkey, the shapes inside the lines were what we cut out so they would make nice little wells for the paint to go into. For the snowflake, we instructed Otherplan Classic to cut everywhere the image had a fill (the black areas).
- Be sure your tools fit the drawing, or the Othermill won’t cut those areas. In other words, the size of your smallest stroke width should be just a little wider than the diameter of the smallest tool you use.
- Find the command that turns your object or strokes into paths. In Inkscape, click Path > Stroke to Path or Object > Path.
- Once you’ve turned your image into paths, click on File > Save As and select Plain SVG.
- Import your newly created .svg file into Otherplan Classic and see how it looks.
For more on .svg files, check out our guide.
Step 3: If the Image You Like Isn’t an SVG
Here’s how to convert it into one:
- First, open up your graphics software and import your file. Once again, we’re using Inkscape here.
- Open the Document Properties panel. Set the size of your page to the exact dimensions you want your finished project to be and save.
- Resize your image so it fits inside the page.
- Then, select the image and go to Path > Trace Bitmap. Trace Bitmap has a neat array of options to choose from that can make a difference in how your image looks when imported into Otherplan Classic. If you’ve never used this function before, see this really nice quick tutorial for a rundown on what everything in this panel does.
- Once your image has been traced, select and discard the original.
- Save the image as an .svg and import it into Otherplan Classic to see how it looks on the machining bed.
Step 4: Notes on Cutting Metal
Every material machines slightly differently and Otherplan Classic has many default values built in. Sometimes, the material you want to use isn’t in Otherplan Classic, and you’ll have to make a few changes so the Othermill cuts well.
For example, we used brass for the turkey, but brass is not a material listed in Otherplan Classic (yet!).
- Start by selecting “Anodized Aluminum” as the material.
- Then turn on BitBreaker Mode (Otherplan Classic > Preferences > check the BitBreaker Mode box). BitBreaker brings up the Advanced button on the plan panel. If you click it, you’ll see a new panel with a lot of useful options. On the bottom half, under the tool menu, you can adjust the feed rate, spindle speed, and the max pass depth.
The rule of thumb we use for cutting metal is that you want a very shallow pass depth, at a very high rate of spin.
- For the brass turkey, change the max pass depth to .003" (.0762 mm) for the large tool.
- Then go to the tool menu and select the smaller tool. Change that pass depth to .001" (.0254 mm).
- For each tool, make sure the spindle speed (RPM) is 12,000.
While we’re in this panel, change the view of the turkey so the negative space would be engraved, rather than the line art. To do this, go to the top of the panel to the Invert menu, and selected “Yes, within cutout.”
Step 5: Set Up Your Othermill and Otherplan Classic
Your image might need a little adjustment after you’ve seen what it looks like in Otherplan Classic. You can go back to your graphics editor, update your image, and just click on the Refresh icon in your imported plan window.
After it looks how you want:
- Power on the machine and run the homing sequence. If you need a refresher on how to set your mill up, have a look at our Getting Started guide.
- Set your tools in the window that pops up when you import your .svg file. We used a 1/32" end mill for the engraving and 1/16" for the cutout. You can use a 1/64" end mill for fine detail, if you like.
- Use calipers to measure your material. Enter the dimensions into the Setup Material panel.
- On the back side of your metal, apply one smooth layer of double-sided sticky tape that completely covers the surface. Don’t let the tape overlap — it’ll make your machining surface uneven and could damage your project.
- Lay your material down square to the lower left corner of the machine bed, and press it down firmly. If you want extra hold (always a good idea) you can also run a bead of hot glue around the edge of your material.
- Insert your first tool into the Othermill. If you don’t know which tool this will be, once you’ve set everything else up in your machine and software, you can click on Start Cutting in your plan window, and the machine will tell you which tool you’ll need. The machine and software will run the tool-locating sequence and tell you which tool to use.
Once the machine starts cutting, keep a close eye on it to make sure nothing goes south. Cutting metal can take a while, so have patience. Settle in because you should never leave a running mill unattended.
Step 6: Enamel Your Project and Enjoy!
Now you’re ready to add color to your piece:
- Get out your craft enamel paints in a well-ventilated area, and wear breathing protection and gloves.
- Use the toothpick to apply tiny amounts of paint where you like. Gently poke the paint puddles with a toothpick until capillary action fills in the space.
- If you color outside the lines, wait till the paint is tacky (not dry!), then use a clean toothpick to rub off the excess. This will also burnish the exposed metal and make it pop out in your enamel.
- Don’t use abrasives like sandpaper or Scotch-Brite on your project. They tend to darken your paint’s color and leave residue.
- Once you’re done and you’ve let the pieces dry for a few hours, you can add a layer of clear enamel over the top to protect your color.
- Once that’s dry, add jewelry findings to the project and turn them in to necklaces, earrings, pins, and other lovely things.
If you have any questions, send us a note at firstname.lastname@example.org. We’re here to help!