Advanced Adobe for Laser Design: Optimizing Layers, Smart Guides, and Kerf Testing

In digital fabrication and laser cutting, precision is key to turning your creative visions into reality. To dive into the intricacies of optimizing your laser design process, we sat down with Damond Barkley, the Manager of Digital Fabrication and Electronics at NextFab in South Philadephia. Damond specializes in prototyping for robotics, and he’s currently designing a class at NextFab where students can build their very own RC car. Check out the classes link to see when it goes live and sign up for all of our other exciting workshops!

Optimizing Layers for Laser Design

A fundamental aspect of laser design is optimizing layers, which will help keep things clean and organized.

Organizing by color

Damond recommends separating your design elements by colors. Utilize up to 8 color callouts – the maximum allowed by Universal Lasers –  including RGB red, RGB  black, 0 green, 0 blue, green, blue, magenta, and yellow. 

By segmenting layers based on these colors, it’s easier to stay organized and troubleshoot issues. For example, if a color is off when sending the file to the printer, it means it was not set correctly. When the layers are separated this way, you can bring up the toolbar, select the color that’s showing up incorrectly, and make sure it matches the hexadecimal color code of the color you’re using so that it’s picked up. Keep in mind that different laser brands have different settings that the file needs to meet (parameters). Trotech and Universal Lasers need them to match exactly or else the colors won’t show up.

Organizing by priority

Another option for organizing layers is by priority. Damond advocates for prioritizing layers based on etching or cutting, and then breaking down the layers into colors within both categories. This strategic approach allows for efficient troubleshooting and ensures optimal laser performance. For instance, if the etching needs to be redone, you can turn off all the other layers and just run the etching layer in the color needed.

Harnessing the Power of Smart Guides

Smart Guides, appearing in pink, act as visual aids for alignment and organization. They ensure your elements are impeccably positioned, contributing to a clean and professional finish. While not mandatory, Smart Guides optimize document design, enhancing accuracy and visual appeal, as everything will be placed using the guide measurements. 

Manual guides are non-printable lines that can be added to a document based on the designers’ specifications. Damond recommends using these guides when building a template with custom boundaries since they give the user more control.

Precision with Kerf Testing

Kerf testing is an essential practice for laser design enthusiasts. In his resource called Understanding Laser Kerf, Damond explains, “The laser vaporizes a certain amount of material when performing a cutting operation. The space left after a cut is called a kerf. Kerf is a common term used across vocations. In most cases, kerf is defined as the width of material that is removed by a cutting process. There is no way to get rid of kerf, you can only account for it.”

Understanding the kerf size relative to your material is crucial for achieving the desired dimensions. Damond recommends conducting kerf tests to determine the exact size variance and adjust your designs accordingly. This meticulous approach ensures a snug fit for interlocking pieces, eliminating the need for excessive glue or post-production adjustments.

He goes on to say, “For laser cutting, the kerf ranges based on material, materials thickness, lens focal length, air supply, cleanliness of mirrors and optics, and other environmental factors. Due to these factors, NextFab can only provide an approximation of kerf across all our lasers. As a sweeping generalization, about .013″ of kerf is a good place to start, but realize that it can range from 0.006″ to 0.016.” Individual results may vary. 

It is recommended to do a test cut before cutting large-scale, time-consuming, expensive materials or any work that involves using kerf. For operations where one piece of material needs to fit into another, like inlays or press fits, you’ll need to compensate for kerf by offsetting the linework.

The shape of the kerf also becomes a factor as it is larger at the top than at the bottom.

Note the shape of the kerf. You’ll need to do some other operations to account for this shape, namely mirroring the design.

In Adobe Illustrator, leveraging offset paths and adjusting sizes by millimeters allows you to accommodate kerf variations effortlessly. This precision engineering not only enhances the structural integrity of your designs but also opens up creative possibilities like finger joint boxes and intricate assemblies. 

Damond provided a step-by-step example of proper kerf testing.

A good way to test the kerf of a laser would be to make a measurable cut. A 10mm square cut works really well for this as you’ll get a measure at a very useful increment. In Illustrator, you can make a 10 x 10mm square and send it to the laser for cutting.

Once cut, you’ll notice there is space between the material and the cut you’ve made. That spacing is the loss from the laser vaporizing the material you are cutting.

Next, you’ll want to take that cut square and measure it. Here, I’m using a caliper to get my measurement of 9.7mm.

So, my 10mm square setting – 9.7mm actual cut = .3mm laser kerf. This is evident by the wiggle room the square has within the negative space.

It is a good idea to test out a few Offset cuts to determine what works for you. For objects like finger joints, accurate kerf measurements can help you to achieve the ideal spacing for a pressure-fit seal without the need of glue.

Here, I’ve made test keys. They may all look the same, but they are offset slightly to compensate for the kerf.

The 10mm block falls through, as we expected. The 10.3mm block also has just enough room to fall through as the .3mm kerf is on both sides. The 10.6mm has a firm fit, with very little wiggle room.

Knowing your kerf allows you to get accurate measurements and apply them to your laser files. This becomes incredibly important if your cuts need to be combined into a larger collection. For more information about how to account for kerf, try taking our Universal Lasers II class and learn about press fits and inlays.

Now that you’ve learned some advanced Adobe techniques, let your creativity flourish as you leverage these tools to craft impeccable laser-cut masterpieces!