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.

Comments

[DenisA10]

what software do you use, I want to put names in mine, it is fun, software sucks.

I make wood pens and want to put names on them. [e-mail]

[PicEngraver]

Hi Andy,

Thank you for this Instructable. Mine just arrived today, and I will be converting it to run with GRBL and, of course, Pic software.
All the best,
John Champlain
www.picengrave.com

[sailorjohn34]

How do you plan to run GRBL on this machine? I have been thinking about replacing the board with an arduino uno so that I can add a cooling fan, a work light, and maybe even another axis. I have the arduino uno and the cnc shield. I've started building one from scratch but I threw that project out the window and replaced it with one that's built out of a flatbed scanner and a printer head drive assy. I haven't finished this yet, but when done it will be able to "engrave" 10" wide (X) by 14" long (Y)

[bball5]

Do you have build plans for using a scanner a printer head? I've been beating my head against a wall trying to figure out how to use my 2 old "all-in-one"s and this seems like a great idea

[PicEngraver]

Sorry, but I shelved this project for a while, and quite frankly, I forgot about it.

My intention was, however, to use an Arduino UNO and Sparkfun stepper drivers, and throwaway the electronics that came with the machine. I planned to use my own software, too. www.picengrave.com

John

[John T MacF Mood]

I've ordered a slightly larger base model, same 500 Mw output (bigger platen). I'm wondering how long your unit took to arrive? It seems interminabley long to me, but I did order around a week and a half before Chinese New Year! (Happy Year of The Monkey.)

Thanks,

John

[als_liahona]

Thanks John! That will be interesting! I still need to upgrade the belts and etc. on my Shapeoko 2 laser the way your Instructables.com article outlines!

For those reading this that don't know already, John has done amazing work. His PicEngrave software is great. You can see it featured in my Shapeoko 2 CNC Laser article (https://www.instructables.com/id/CNC-Laser-for-Printing-Images-and-Engraving-Shapeo/) as well as in this article by PicEngraveToo:

https://www.instructables.com/id/Shapeoko-2-Arduino-UNO-R3-grbl-9g-8bit-Raster-Phot/.

[qdogg]

What does one need to know & what kind of software needed to use the miniature laser engraver you mentioned? I'm thinking about getting one, but I need to be prepared since the poor instructions aren't going to be very helpful.

[sailorjohn34]

When I ordered mine, I didn't know anything about CNC of any kind other than I thought it was really fascinating. Now I've modified my carver so that it's got manual seek buttons. It took about a week of reading and watching youtube to figure out how exactly everything works.. but the day I pulled it out of the box, I printed off about 10 items. My wife and I used it this year to make christmas ornaments out of wood. I love it. It's as simple as... select an image, drag it to the carver software, send to printer, check alignment/ centering of item then select your desired burn time, and hit start... It's very easy.

[hplasm]

Note that despite what the advertising says- on ALL sites that sell these- there is NO MAC software included, nor available for download.

Despite this, I received mine within a week of ordering from Gearbest, and the build quality is just fine. Now I'll need to draw a pentagram and use Windoze... :( until I can figure something out.

[als_liahona]

Yes, it is very frustrating to have a severely overpriced computer that can't do what you need it to do... ;) Those macs are always just one byte short of a full fruit. But they make them look good. :)

It's not the world's best solution, but you might try VMware Fusion with a copy of Windows for things like this. But frankly, you can probably buy an old Windows PC (laptop) or even a new week but usable Windows Tablet (they have some that are less than $100 out there) that you could use for this special purpose. Just be sure what you get has a USB port. Some of the cheap tablets don't or else they only have a micro-USB port in which case you'll need an adapter.

Best Wishes.

[hplasm]

I bought this on the strength of the MAC drivers, but wouldn't spend an extra penny on MS software (sic). I'll try a copy of NT that I have lying around somewhere, else I'll have to get serious... ;)

[als_liahona]

Interesting. Having written software extensively for multiple platforms, I don't know why you would think MAC drivers are strong, but to each his own. Your attitude towards Windows was justified a decade ago, but not so much any more.

FWIW, the Windows driver appears to be similar to an FTDI usb-serial driver, providing a COM port for the software to open. I have a capture from the debugger of all of the reads and writes to/from the device when sending an image and kicking off the engraving. I was trying to debug the problem I had with the software early on. There does not appear to be much to it. Having said that, you could probably just as easily get the developer of the Windows software to write Mac software if they think it will help them sell more units.

[hplasm]

Ah- I see you misunderstand. I don't see the MAC drivers as 'stronger' than windows, whether they are or not, I see them as Missing.

The kit is advertised as Windows and Mac compatible, but there is no Mac software at all.

Think of it as a filling station advertising Petrol and Diesel, but when you arrive, it only has Petrol pumps. No use to say "Well, you could always buy another car just to use the fuel here."

I have asked the vendor about it, but have had no reply.

Perhaps you could publish your findings on the protocol? I'm sure there are lots of people on here who would like to write something to use this device, say on a Raspberry Pi or Beaglebone or some such device.

I can see the GUI if I run the .exe on Wine, but getting the USB connection may be a bit of a challenge... ;)

[als_liahona]

I see. I did misunderstand. And you are right that gearbest.com lists Mac, but the trusfer.com site where you get the software does NOT. That's not good.

I don't want to jump into potential legal issues from disclosing what I found as I tried to debug a particular problem, but I'd be happy to show someone how to capture the same output and they can worry about whether or not the software grants them the right to use what they find or not. (Generally speaking this type of reverse engineering is LEGAL as long as you are not producing a competing product, but find out for yourself from a lawyer -- which I am not -- as things may be different in your jurisdiction.)

USE AT YOUR OWN RISK: What follows will only make sense if you have a little bit of experience with debugging applications on Windows. If you don't, you will not want to try this.

The key is to connect windbg.exe (Debugging Tools for Windows) to the engraving program. Before clicking on the button that opens the selected COM port, set a breakpoint on CreateFileA (newer versions might be Unicode in which case use CreateFileW):

bp kernel32!CreateFileA "da poi(esp+4);g poi(esp);r"

Then let it run and when it breaks after opening the COM port, EAX will hold the HANDLE of the COM port.

At that point you can clear that breakpoint, or change it so it doesn't keep stopping there "bp kernel32!CreateFileA "da poi(esp+4); g". (This will display the name of the file being opened but then continue, where as the previous version of the breakpoint displayed the file name, continued until CreateFileA returned, and then stopped so that you could examine the return value in EAX.)

With the file handle known, you can know watch for and log reads and writes to the handle with breakpoints like the following. Change the "370" to whatever the handle value (value of EAX) from above was:

bp KERNEL32!WriteFile "r @$t1=poi(esp+4);r @$t2=poi(esp+8);r @$t3=poi(esp+c);.if(@$t1==370){.echo 'COM WRITE';db @$t2 @$t2 + @$t3};g"
bp KERNEL32!ReadFile "r @$t1=poi(esp+4);r @$t2=poi(esp+8);r @$t3=poi(esp+c);.if(@$t1==370){.echo 'COM READ';db @$t2 @$t2 + @$t3};g"

Those 2 breakpoints will check to see if the handle matches ($t1 == 370) the value from CreateFile on the COM port, and if so, it will spit out "COM READ" followed by the data read, for ReadFile, and similar for WriteFile.

After that, turn on logging to a file (look up the help for the .logo command, or use the option in the menus), and let the program continue. You will then capture all reads and writes to that file. Each time you execute a command in the program, like "Send to Machine" you can break into the debugger first, use .echo "About to click Send To Machine", and then continue and click the button. By so doing you can record all of the commands and then parse them to see what is happening.

So if you are programmer that should be fairly easy and you will have most of what you need. The other side will be the driver that opens the device, and I have NOT looked at how it works, and probably will not for lack of time. Hopefully they will rectify the issue with not having a Mac driver or at least remove it from the listing on the website.

What would be really cool is if they wrote the USB driver portion using the UMDF (User mode driver framework) and released it for ARM/IoT devices. Then you could use a Raspberry Pi running Windows 10, and set it up with a Web Interface, so you could design images on any device and submit them to the laser engraver. :)

[hplasm]

Thanks- that should make a good start :)

[als_liahona]

Step 3 cover most of it. The software comes with the device on a micro SD card and can also be downloaded from a website. You create a 512x512 pixel image in whatever paint type program, save it as a .jpeg or .png, and then drag and drop it into their software. From there you click the "Send" (image to the machine -- some language like that) button. And then click the Engrave (again something like that) button.

You do need to focus the laser but that is only a matter of turning the focus ring until you get the sharpest, smallest dot possible before you start engraving. Before you start the engraving make sure to put the safety goggles on.

[jimthree]

Does anyone know how these DVD/CD carriage based machines do end-stop detection?

[sailorjohn34]

They don't really use end stop. They tend to overrun bad if you move the axis prior to start up. They do a homing cycle upon start up, then once running they only move x steps in either direction. I hope this helps. I did manage to add 2 buttons on the empty ports of the board so that I can have manual seeking. This helps when loading and unloading material from the bed. The neje dk8 is enclosed with such small openings to reach thru.

[ejnmn]

Als, I have the same or similar NEJE cutter. Mine is 300mw. I agree, its a lot of fun. However, the LiteFire software that came with it has been found by Symantec to have a virus in it. May just be my copy, but I can't fine it anywhere else that is clean, nor can I get any response from the NEJE wiki, which is brand new. Do you have any alternative software that you have used, or do you know where I can get a clean copy of Lite Fire?