What’s a lithophane? It’s basically a greyscale image carved into a material that shows translucency, displaying contrast when light is projected behind the image. While creating this sort of effect can be achieved a few different ways, one of the most satisfying results comes from creating this type of photographic variant with a CNC machine. A high-quality CNC machine and a ball-nose bit can create three-dimensional images that make great gifts.
For my very first lithophane, I had access to some sample pieces of countertop material that is very similar to Corian®, called HI-MACS® by LX Hausys. Being new to this type of project, it took three attempts to achieve the clarity I knew the ShopBot CNC machine could produce.
This next bit of info is a real gamechanger. If you haven’t checked out ShopBot Labs, now is the time! ShopBot has recently started developing simple, purpose-built apps to accomplish very specific tasks, without the need for traditional CAD software. One of these apps is the lithophane creator. And when I tell you this app makes it easy, I truly mean it. I am not an engineer or designer. I continue to learn as I go. Traditional CAD software is still the most versatile choice for professional use, however, certain projects simply no longer necessitate traditional CAD software to achieve professional results. The lithophane app in the Shopbot Labs collection has presets that work, right off the bat. All you have to do is upload an image, be sure your material width and height are appropriate for the size of the image, enter the thickness of your material and bit size, and click “generate tool path”. That’s it! Of course, there are ways to customize further within the app, but the presets work great as-is. With very little effort, you can now save the type of file you need and get right to cutting.
I wasn’t sure what sort of resolution to expect, so on my first attempt, I used a 1/4” ball-nose bit. The file took about one and a half hours, and it was just a bit too blurry. I saved a new version of the cut file with a 1/8” bit. This second attempt took a little over three hours and provided a step up in overall clarity. From a distance, it looked good enough, but I knew it could be better. I then saved a cut file from the app with a 1/16” bit selected. Can you guess how long it took on this third and final attempt? If you guessed 7hr 22min 44sec, you are scary smart! Every smaller bit accounted for about double the amount of time of the previous. And yes, over seven hours is a long time for a 5″x6″ 3D carving of a photo, but keep in mind that there were a lot of fine details in this image and many CNC professionals run much larger format lithophane projects that we’ve heard can take as long as 36 hours to complete. Seven doesn’t sound as bad, now, does it? And I could have cut down the total time for my file if I had applied a gradient around the boarder. It’s always a good idea to consider editing a photo prior to saving the tool path file.
I am very happy with the final version, as is my wife who I made this project for. This got me thinking – Wouldn’t it be great to machine a photo frame for this lithophane with the ShopBot? I’ll be sure to write about my experience creating my first CNC-made photo frame when that happens.