How Deep Can Laser Engraving Go
Laser Engraver Guide – All About Laser Engraving
Nowadays 3D printing isn't the only manufacturing technology found in the maker scene. Once strictly used by industrial manufacturers, laser engraving is increasingly adopted by small businesses, product designers, makers, and even hobbyists.
In some cases, a laser engraver might prove to be the most advantageous manufacturing technology for your specific application.
Here's everything you need to know about laser engravers before pulling out your wallet.
LASER ENGRAVING TECHNOLOGY
How does Laser Engraving work?
The high heat of the laser beam vaporizes the material thereby cutting into the part's surface and physically removing material. This process leaves a cavity in the surfaces that is not only visible with a high contrast but also noticeable by touch. There are noteworthy differences in the depth of this cavity that varies between 0.02″ in metals to 0.125″ in harder materials.
Usually, the engraved areas become black. Multi-layer materials offer an alternative, as they enable to engrave other colors than black. By removing the top layers the lower layers become visible.
Another variant of laser engraving is relief engraving. The laser creates a deep engraving with distinct heights. This variant is beyond any doubt the most impressive, since the overall effect is that of a wooden sculpture. If you want to create a relief engraving, you need a grayscale design and set your laser to translate the different values into different heights.
What are typical applications of Laser Engraving?
This process has become very popular for customizing parts made off metal, leather plastics, wood, glass, and acrylic. In particular, it is a great tool to add numbers, logos, images and serial numbers to parts.
Laser engraving is today a technology commonly used for producing promotional products like pens, signs, and displays.
Outside the maker scene, many consumers enjoy the possibilities of laser engraving to produce objects customized with their names. One of the most noticeably applications is engraved jewelry, like wedding rings.
How does Laser Engraving compare to traditional techniques?
In short, the idea of "one tool fits all" applies. Laser engraving is a universal tool that can be applied to a wide range of materials. Meaning that you don't need to buy dedicated tools for each of them.
Laser engraving is a money-saving technology. When parts are engraved using mechanical tools it is necessary to fasten them with clamps. This adds to the work hours and may damage the parts. Since laser engraving is a contactless technology that does not require fastening parts, you save not only time, but you also avoid the risk of damaging the parts.
Conversely, this also means that your tools like drills or cutters do not suffer from wear and need to be replaced saving you even more money.
Lasers engrave your designs with the highest precision onto the parts and can achieve an extremely high degree of detail. Moreover, since every design is saved as a file you can reproduce them at the same level of quality.
Traditional carpentry, wood-cutting and leather decorating are crafts that require long years of practical training to achieve mastery. Love it or hate it, but with laser engraving anyone can create items at a level of quality high enough to make a living! – Many people using laser engravings sell their goods on platforms like Etsy, Ponoko etc.
Compared to CNC engraving machines, laser engraving is not only faster, but you can draw on a larger number of font options and the end result is by far more legible.
HOW TO DESIGN FOR LASER ENGRAVING
For the short read, peruse our six-step guide. If you want to delve in deeper, consult our in-depth dossiers that will help your improve your laser engraving results.
- First, make yourself familiar with the distinct effects raster engraving and vector engraving create on different materials. This allows you to design your part in way that is aesthetically pleasing and cost-efficient. – Learn about the fundamental differences between these two techniques.
- Wood is not the same as stone. You should also be aware of the different ways materials react to laser engraving. – Read the laser engraving materials guide to learn how to achieve what effect on the desired material.
- Next, create the design in a graphics program like Gimp, or Photoshop for raster files and AutoCAD, Illustrator, or InkScape for vector files. – Learn more about the software used to create laser engraving graphics.
- Transfer the file into the laser engraver and fasten the part on the work platform. Depending on the design and materials, you may use tape, but some laser engravers offer mechanical solutions.
- Choose the laser engraving settings according to the specifications provided by the manufacturer. Use presets to speed up this step of the process. – Read about the Do's & Don'ts of how to maintain your laser engraver and achieve eye-catching effects.
- Run the laser engraver.
- Usually, it is not necessary to post-process laser engraving parts. If necessary assemble the part, i.e. attach chains, glue walls and components together. In short, work your magic.
Raster Engraving vs Vector Engraving
You can use both raster and vector files for laser marking, engraving and etching. However, depending on the intended use, you should choose which one you apply for your design.
Raster files (JPG, PNG etc.) are the go-to format for large engravings like fillet letters, images and stamps. If you want to engrave any image made with a camera, raster engraving is what you want to use. Just like on computer screens, the image is put together by gradually adding points to form any shape you can imagine. Sometimes this method is also called "area engraving". This method is especially well suited to materials like acrylic because it lends a beautiful frosted finish with a distinct contrast. Avoid raster engraving large glass, stone, and ceramic surfaces, since the end results may be visually uneven.
Vector files (SVG, EPS etc.) are composed of lines that are traced onto the surface sequentially. If your design consists of minute lines and curves, then vector engraving is the appropriate method. Professionals also call this approach "scoring", and sometimes it is also called "line engraving". Vector engraving lends itself well to wood because the burned outline creates a stunning contrast with the warm surface of the material. It is less suitable for materials like acrylic, since the melted outline is only faintly visible. The video above illustrates the strengths and weaknesses of both methods.
For the best effect, it may be worthwhile to combine both methods. The final parts feature the evenly engraved surface from raster engraving and also the crisp outline created by the vector engraving. This effect works especially well on wood.
The difference between both methods can be a substantial cost saver even when you order only one piece from an online service. But how do you decide? As a rule of thumb, if your surface details consist of large, relatively simple shapes you should opt for vector engraving, as this is the quicker and thus more economic laser engraving method. However, if the design covers a large area that contains many intricate details, you should choose raster engraving method. However, ultimately you should decide based on what works best for your design!
Guide to Laser Engraving Materials
Laser engraving is so much more than fastening any material in the work area and pushing a button. Every material has its own quirks and idiosyncrasies that will sometimes help you achieve your design goal and sometimes make it hard on you. The following list will guide you through the properties of the most common materials.
It is possible to laser engrave finished leather, producing a look similar to hot-branding. Avoid raster marking large surfaces, since the leather will turn powdery. Therefore, vector marking is recommended.
Since leather is a natural material, it may deform during laser engraving if too much power is applied.
Because of the many varieties of leather it is difficult to come up with a general rule for laser engraving it. Hence, there is no way around determining the optimal laser engraving settings for each kind separately. To this end test your machine with a grayscale matrix (see above).
Because of the many varieties of paper and cardboard it is advisable to determine the optimal laser engraving settings for each kind separately. To this end test your machine with a grayscale matrix (see above).
Besides natural woods there is also plywood, which has several advantages. This laser engraving material consists of several sheets of wood that are glued together. As a result, plywood boasts a raised mechanical resistance, water resistance and lightness. All these properties have made plywood a staple for builders, designers, artists, and craftsmen.
In terms of laser engraving, plywood has an additional advantage over natural wood. When cut into sheets, the latter reveals grains in alternating shades that stem from different kinds of growth during the seasons. These differences also translate into different laser engraved surfaces. Usually, the lighter areas will come out lighter and the dark areas will be darker.
As a rule of thumb, unless the desired look of your design is kind of zebra pattern, you will be better off using plywood that has a uniform surface.
In addition, you should always apply higher laser power when engraving hard wood. Only then will you smooth results.
To determine the optimal laser engraving settings, test your machine with a grayscale matrix (see above).
The effects the laser has onto the glass surface can be manipulated using a number of practical methods.
Apply a moist paper towel to achieve a smoother surface finish and a white engraving result. Take care that there are no air bubbles or overlaps, because this would distort the effect. Once the engraving is finished the paper towel can be wiped off easily.
An alternative to paper towels is application tape. Like moist paper towels, application tape is an excellent measure against surface roughening. The same caveat concerning air bubbles and overlaps apply. However, the final engraving color is not a bright white, but looks grey. Once the engraving is finished the tape residue can be removed off easily.
But what to do when your laser engraver has not enough power to engrave glass? Even then you can achieve designs with high-contrasts! Simply mask the glass surface with tape. Then you engrave the design into the tape. Next, cover the revealed area of the tape with a thin layer of paint using a brush. After the paint has dried, peel the tape and remove the tape residue carefully.
Experience shows that it can be piece of work to laser engrave stone. You will get the best results with polished stones. To avoid distortions of the laser engraving motif, try to use stones that have a flat surface. You can align natural stones with the laser by using modeling clay as a support. When you set the laser's focus, apply an average value to achieve a uniform result
If your results are poor, consider changing the Z-offset value. This simple trick can significantly improve the result of your engraving. Many professional laser engravers report that hard stones are easier to process if you choose a negative Z-offset value of 1mm or even more. The physics behind this workaround are simple. The closer the surface to be engraved is to the laser, the more energy enters.
But what to do when your laser engraver has not enough power to engrave stone? Or, when working with extremely hard stones that yield no satisfying results? Even then you can achieve designs with high-contrasts! Simply mask the glass surface with tape. Then you engrave the design into the tape. Next, cover the revealed area of the tape with a thin layer of paint using a brush. After the paint has dried, peel the tape and remove the tape residue carefully from the stone's surface.
Guide to Laser Engraving Materials
Raster Engraving
Files for use in raster engraving can be created in a many graphic programs. In fact, if you are reading this on a Windows, macOS or Linux PC, then you have a graphics program already installed with the operating system that will suffice for your basic needs.
Laser Engraver Software #1: Adobe Photoshop
Undoubtedly, Photoshop is the go-to raster image solution. Its mind boggling feature-set makes is not only popular among professionals, but a series of trimmed down versions for mobile devices are also suitable to consumers who wish to enhance their personal snapshots or make their feet wet in graphic design.
If you are looking for a free alternative to Photoshop, try GIMP.
Laser Engraver Software #2 GIMP
GIMP (GNU Image Manipulation Program) is a free raster graphics editor that is considered by many to be on par with Photoshop. It features comprehensive image editing tools, like as transformation, selection, layer and masking tools, but also filters and brushes. Hence, this free and open source graphics editor is superbly equipped for creating raster engraving files.
Vector Engraving
Vector engraving files are created in programs that offer support for vector formats like AI, DXF, EPS, PDF, and SVG. In general, these softwares come with different tools to generate the necessary files. Depending on the machine you are using, a different setup is required. For example, if you want to combine vector engraving and raster engraving in the same design, it may be necessary to create separate files or assign different colors for each technique.
Laser Engraver Software #3: AutoCAD
First published in 1982, AutoCAD is one of the most popular CAD software available today. It's large feature-set makes it a standard across a wide range of industries: architecture, engineering, graphic design, management, and others. Moreover, it saves its designs as vector files that can be used for laser engraving.
If you are looking for a free alternative to AutoCAD, try FreeCAD.
Laser Engraving Software #4: FreeCAD
Designed around parametric modeling, FreeCAD is a solid free CAD software. It offers a modular architecture that allows plugins to be mounted to the core application. This means FreeCAD can be used in widely different fields like architecture, engineering, robotics, and CAM.
Laser Engraving Software #5: Adobe Illustrator
Illustrator is Adobe's go-to vector graphic software. The range of tools that this program offers is probably unsurpassed. On the flip side, it takes extensive training until you can fully leverage on Illustrator's capabilities and make good on your investment.
If you are looking for a free alternative to Adobe Illustrator, try InkScape.
Laser Engraver Software #6: InkScape
InkScape is a free vector software that has been actively developed since 2003, so you safely say that is now a mature and reliable piece of vector software. It implements the complete SVG standard meaning your designs are not stuck in a proprietary format, but an open standard. Over the years the toolset of InkScape has grown substantially. Today, it includes handy tools like image tracing, i.e. you can convert a raster file into a vector file automatically. InkScape is available for free download.
Do's & Don'ts
So, you want to know how you can improve your laser engravings? Here are a few tricks that will help achieve that goal.
Calibrate your Laser
There are a few hacks that allow you to get you started in no time. However, if you are earnest about #laser engraving#, then there is no way around measuring the focal point of your laser. We suggest that you test 10 to 15 increment of 1mm in the Z-axis. Prepare a series of files that contain a straight line and the value you are testing. Once, your series of tests is complete, compare the results. You want the laser engraving with the thinnest solid line. Use this value for your future laser engravings.
The same applies to testing the intensity of colors. Modern laser engraving machines can achieve a broad spectrum of shades. However, the appearance of the final engraving cannot not always be deduced by looking at the raster file. By laser engraving a grayscale matrix onto the desired material is an easy way to achieve predictable results, as you can "read" the intensity of shades on a scale from 0 (white) to 100 (black). Ideally, you should run this test for every material you want to laser engrave for the best possible results.
Avoid Smoke Stains
Laser engraving on materials, like wood and leather, can sometimes stain the surface surrounding the engraved area. While some makers like this "branded" look, it can be easily avoided. Protect the surface of the part using masking tape. The tape is so thin that it will not diminish the power of the laser much. If you feel that may be an issue, just increase the laser power a few notches. After the laser engraver is done, peal the masking tape off your part.
Keep your Laser Engraver Clean
Tidiness at the workplace should be a non-brainer. However, with regard to laser engraving we're not merely talking about courtesy towards your co-workers. Materials like wood, plastics or rubber leave large amounts of dust that may cause unwanted results like discolorations, burnt debris or even distortions.
Install an exhaust system that has the necessary capacities. This will take a lot of weight of your shoulders. However, it will clean the entire machine.
Hence, you should clean the laser engraver regularly by hand. You can remove most of the dust with a simply kitchen-cloth.
You should also pay extra attention to the machine head and the laser lens. These components should be free from dust and smut at all times to avoid laser engraving mistakes.
In case your part is smaller than the work platform, cover the rest with paper. This simple trick will increase the efficiency of your exhaust system and save you a lot of manual cleaning.
Use Templates to Engrave Multiple Parts in One Session
Templates are safe and cost-effective way to laser engrave multiple parts in one process. They fasten the objects into fixed positions that are known to you and your laser engraving software. Hence, you are not bound to laser engrave objects one by one, but instead, you can process entire trays in one session.
Here are our tips for making your laser engraving process more efficient with templates:
Watch out for the volume of your workpieces. For thin objects flat templates are sufficient to keep them in place. However, thick objects like pens require thicker templates to keep them from rolling away.
In case you work with a large number of different template, make sure to write (or better laser engrave) the name of the graphics file in question on to the template. This will make it so much easier to match your tools in your daily work.
File small templates in folders to keep them save and organized. Simply laser cut holes and they will be quickly at hand.
HOW TO BUY A LASER ENGRAVER
These days laser engravers come in all shapes and sizes. You can even start out with a small desktop machine. But apart from the obvious difference in size, what do you need to look out for when choosing a laser engraving machine? Here is a list of criteria that will help you make up your mind.
Small Laser Engravers
Small laser engravers can be an excellent alternative to large industrial models. But this category of laser engravers has its own set of problems: the surface area that can be processed in these machines is much smaller – think a letter size part, although many machines offer only half that size.
Crowdfunding Laser Engravers
You should thinkt twice, in case you are eyeing a crowndfounding laser engraver. Laser beams can cause irreparable harm to your eyes and skin if they are not expertly contained within the casings. These kits cannot ensure the same level of safety as laser engravers that have been assembled by professionals and rigorously tested.
Our advice is that as a beginner you buy a machine that is already fully assembled. If you have already experience with laser engraving and know how to safely assemble technical devices then we hope that you are up to the task.
If the company behind your laser engraver should go bankrupt (not a rare event in the highly volatile crowdfunding world) you will be left without a supply of spare parts and expert knowledge for maintaining your machine.
Industrial Grade Laser Engravers
Industrial grade laser engravers are not only expensive to buy, they also entail high costs of maintenance. For example, the laser unit needs to be replaced every 5 to 6 years. In case you have bought an industrial grade machine, this is not a quick replacement that you can do by yourself with a screwdriver. No no, you have to send the entire device to the manufacturer.
The laser unit alone can cost up to 3000$, and on top of that you have to pay for the man hours it takes to install it. So, before you decide to invest thousands of dollars into an industrial grade laser engraver, make sure that you also have the money necessary for maintaining it.
Laser Safety
Watch out for laser safety! Class 4 lasers can cause serious damage when operated irresponsibly. Assess your needs carefully before you make a decision. you will sleep easier if you buy a machine that is less powerful, but still does what you need.
Each class of lasers requires better eye protection. Do your research and find out whether the laser engraver you have in mind, includes the necessary glasses. If not, any responsible manufacturer will proactively tell you what laser class is built into the machines to allow you buying the appropriate protective glasses in advance.
Power Supply
What kind of power connector does the machine require? Can you plug it into any socket in your office / workshop, or do you need a power line to operate it?
It's clear that the laser unit takes a lot of power. However, some people are not aware just how much power the other components consume. The cooling and air exhaustion modules will make themselves felt on your electricity bill. So do the math and try to calculate, if the benefit of setting up a laser engraver in your office or workshop is worth the costs.
Cooling
Strong lasers require constant cooling, but there are important differences between the different solutions. How does the cooling unit of the laser work? Tubes that are made from metal/ceramic use air, and can last up to 5.5 years. However, they are substantially more expensive that cooling tubes made from glass. The latter use water as a cooling agent. The downside of this method is a great deal of inconvenience, since you need to place a bucket next to the laser engraver to catch the waste water.
Exhaust Air
Laser engraving makes a lot of mess. Large amounts of dusts are produced that can be harmful when breathed in. Hence, it is necessary to install an exhaust pipe to maintain a healthy environment in your workshop. This pipe requires a diameter large enough to remove all of the dust. Otherwise, the engraver remains a health hazard.
In addition, you should take into account that air filters produce a lot of noise that may distract you in case you are thinking of setting up a laser engraver in your office.
How Deep Can Laser Engraving Go
Source: https://hymsonthailand.com/laser-engraver-guide/
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