Introduction: Miniature Laser Engraving
If you've read my previous Instructables.com article, where I added a 2 Watt Laser to a Shapeoko 2 you know something about the many things that can be made with a CNC controlled laser. The larger Shapeoko 2 laser is powerful and can accomplish many things, but it isn't great with really small engravings. It also takes a fair amount of setup -- including to some degree restricting access to the room while the laser is running.
I recently learned about a new, very affordable Miniature Laser Engraver. This machine is a lot of fun! It currently costs less than $90 U.S. Unlike my Shapeoko 2 based laser, it takes almost no setup time, there is no need to generate and then manipulate gcode files, and it can be set on the dining room table where you can be engraving within minutes! The kit, available from gearbest.com, includes a set of safety goggles. You may want to obtain additional sets of goggles so that others can watch the engraving process, but this machine is also small enough that you could simply cover it with the shipping box while it runs -- or build a box out of laser-safety acrylic.
In this Instructable, I will demonstrate engraving on several different materials as well as show step-by-step what is involved in making and engraving and image.
Step 1: Capability...
The machine that I have is called a NEJE DK - 5. It can produce an image that is approximately 38mm square. The image above will give you a rough idea of what the machine can do. You'll notice that 38 square millimeters is not very large, but also notice that even the small print is engraved well enough to be readable (even if you do need a magnifying glass to see it!)
It is important to notice that a 72 point font is not 1" tall as it would be if printed from a desktop printer. Instead, it turns out to be about 7mm tall.
Despite not being able to produce large engraving, the engraver produces excellent results in small images -- something my Shapeoko 2 can't do without changing the belts.
Step 2: Engravable Materials...
The NEJE DK - 5 model includes a 500mW blue laser. It is capable of burning/engraving paper, wood, some plastics, chocolate, leather and other similar materials. It is not able to engrave in metal or stone.
Material is held to the acrylic base by two rubber bands. You will find that some materials will hold better with some double sided tape.
Step 3: Setup...
Setup involves two steps. The first is installation of the driver that ships with the device on a micro SD card or which can be downloaded from the manufacturer. After the driver is installed the engraver program can be run from the same media. I've tested it on two different Windows 10 machines.
CAVEAT: I had two initial problems. The first one was images not printing completely because I had left a small piece of the shipping foam under the acrylic base plate. Make sure you don't make the same mistake. The second problem that I had was also with images not printing to completion. This turned out to be a problem with my USB hub. When I replaced it with a new powered USB 2 hub, everything worked perfectly from there on out.
The second part of setting up to engrave is to generate an image. This is easy. Use a program like Microsoft Paint to create a 512 x 512 pixel image. Save the image as either a JPEG or a PNG file.
You can now drag and drop your image into the Laser Engraver program. Once there you can rotate the image if necessary. Then click "Send Image to Machine". Once the image is stored in the laser engraver, it will "draw" (not engrave) a rectangle around the area where the image will be engraved. The rectangle traced will only include those parts of your image with engraving (non-whitespace) in it.
Step 4: Engraving Chocolate...
As you can see from the images, chocolate can be engraved. Each of these engravings were done using only a single pass. The rose was done on a carmel filled Ghirardelli chocolate square (which had a slight crack prior to engraving). The other image is the back side of a Hershey bar segment. A second pass would produce a deeper image.
There was no change in the flavor/taste of the chocolate.
Many foods could be engraved. I tried a slice of cheddar cheese and was surprised to see that it really only sweat where the laser drew on it. I had hoped for burn marks, but it may have had too much moisture. I also had no luck engraving on a marshmallow. :)
Step 5: Engraving on a Bamboo Turner...
I picked up an in expensive ($1.47) bamboo turner at Walmart. As you can see from the photos, it engraves very well. Only a single pass was required to produce an image that still looks great after being washed in the dish washer.
Step 6: Engraving a Leather Cell Phone Case...
Leather (or maybe this is simulated leather) engraves very well and looks great. Even the small text shown in the images can be read clearly (though I need reading glasses to read the smaller print.) The results are crisp and clean.
Video of part of the engraving process is also included. Note that the full image took about 20 minutes to engrave.
Step 7: Engraving on a Plastic Cell Phone Case...
Some plastic material can also be engraved. The images here show a plastic iPhone case that was engraved with a single pass of the NEJE mini laser engraver.
A mini laser engraver opens up a whole new world of possibilities for personalizing small items.