In the summer of 2018, just for fun and a new challenge, I designed a mini LASER burner. It took me exactly 3 months to get there.

See my blog.
The basic idea was that he had to be able to engrave anything, in any position. That is to say, engraving on a t-shorts, the tapestry of the living room, the telephone, a book and as well placed on the wall as on the ceiling, on the hood of a car, etc ... So a device TOTALLY portable. I'm almost there. Today we can say that it can burn on walls, cars, etc ... but not on the ceiling. Internal mechanics do not allow it. It can also cut paper and even 5mm thick honeycomb in one pass (but at 1mm / s). The cutting speed is at most 3mm / s. The drawing file formats used are in GCODE or PNG, JPG, BMP. Yes, you read correctly. It can burn images .... but it's very long. To get a GCODE file, I go through INKSCAPE and GCODE generation extensions. The site J-Tech Photonics explains the steps of creation. A small graphical interface makes it possible to use the burner in a simple and fast way.

Caracteristics:

Power supply: 220Vac / 12Vdc
Laser power: 500mW - 405nm - 12V (can be adapted up to 1.5W)
Max etching / cutting speed: 3 mm / s
Effective area: 95 x 95 mm
Accepted files: GCODE, JPG, BMP, PNG
Overall dimensions: 203 x 185 x 66.5 mm
Interface: Backlit LCD display 26 x 40 mm
Port: USB 2.0
Filter: activated carbon
Resolution: 1750 nm
Accuracy: ~ 50 μm

Step 1: LASER 500mw / 12V - 405 Nm

I use a LASER 500mw / 12V - 405 nm, bought on Aliexpress.

I removed the radiator for space issues.

The LASER is however cooled by the original fan, positioned on the side.

Step 2: The Stepper Motor

The choice of drive motor X and Y axes I have some concerns. I wanted to use floppy drives (small stepper motor) but their power and use was not meeting my expectations. I decided to buy two more standard stepper motors. A type NEMA 8, type 8HS11-0204S.The motor is mounted with 4 screws on the structure of the machine.

The coupling between the M4 threaded rod and the motor is made by a piece of compressed air pipe 1 cm long. To have a perfect centering, I widened the air hose with successively rods diameter 3, 3.5 and 4mm in diameter. Each time, I heated the pipe so that it widens. Then I waited for him to cool down before removing the rod.

Step 3: The Controler

To control the machine, I use a Raspberry Pi Zero equipped with Wifi. He is small and powerful enough to do what I want. See my blog on the subject.
I designed the program in python 3.x under Eclipse IDE on my PC and debuged by ssh link (Wifi) between my PC and the Raspberry Pi Zero .... I know, for novices in computer science, it's gibberish.
The Raspberry Pi works under Rasbian. I optimized its startup so that it is done in 20 seconds instead of almost 1 minute.

Find here all schematics, firmware,...

Send me an email if you want printed parts or PCB.

I adapted a small screen LCD 128x64 pixels.

Three buttons control the machine. The three buttons are soldered on a mini PCB and connected to the Raspberry PI.

The menu is quite simple.The menu consists of three functions: Burn, Configure and Test.