Laser / PenPlotter / CNC from Salvaged Ender 3

thingiverse

This DIY project transforms salvaged Ender 3 3D Printers into functional laser engravers. The working machine is showcased in the following videos: https://www.youtube.com/watch?v=nJvaOsaJ-oE and https://www.youtube.com/watch?v=TFX5HxUCd7c. I refurbish printers for a living, and I had an abundance of spare parts from fixed Ender 3s. The heated bed died, base frame screws were loose, and a board with a blown stepper driver was among the discarded components. I decided to repurpose these parts into something new. Here's what I used from the Ender 3: * Both side base profiles are repurposed as front and back bases * Both Z profiles serve as left and right bases * The X-axis profile is now the X profile * Six count Z-axis wheels function as Y-axis wheels * Three count tool wheels operate as tool wheels * A modified control board with firmware adjustments * LCD display * Existing PSU can be powered using a 12v 3A Buck convertor for laser use * Most screws remain intact * Peeled off magnetic sticker from bed New parts purchased include: * 12v power supply (if existing PSU is not used) * Printing baseplate - a 12x18 steel sheet from Home Depot (any other surface can be used) * Pin 27 adapter for pen plotter (optional) * Spare M3 and M5 screws * Four-core stepper wire * JST connectors (optional for heat shrink or electrical tape) * Magnets for paper holder (if desired) Board modifications: * The PWM on most laser models, such as the NEJE 20w and Chinese brand 7w, accepts 3.3v - 5v. I repurposed the print cooling fan connection but it's a 12v PWM that doesn't work with these lasers. A wire is soldered to an input of FAN mosfat for laser PWM. * To use pen plotter, pin 27 can be used as a servo to move the pen. Strip the last wire of LCD cable or use the Pin 27 adapter. Firmware changes: * The Y Motor now moves in a different direction; set INVERT_Y_DIR true * The X end stop is in a different place; set X_HOME_DIR 1 * Increase bed area by changing X_BED_SIZE to 210 and Y_BED_SIZE to 295 * Set NUM_SERVO 1 for pen plotter * For laser-specific functions: + Uncomment #define SPINDLE_LASER_ENABLE + Set SPINDLE_LASER_PWM_PIN FAN_PIN + Set SPINDLE_DIR_CHANGE false * If a board has blown X or Y drivers, remap pins and use another (Z or E1) port. Find variables like X_STEP_PIN, swap pin numbers with E0, and connect X motor to E0 Port. Todo: * Fix the temperature table of the laser (I'm struggling to find one for Neje laser) * Disable heated bed option * Remove Bed temperature from status screen * Extend Z to make laser focusable via Z stepper * Add smoke extractor * Add a cable chain Coming Soon: * Pen Plotter design * Stepper-controlled Laser focus