Laser cutter / engraver accessory – How to engrave on a Wanhao Duplicator i3

Step by step Instruction
How to engrave on a Wanhao Duplicator i3 a raster picture (ClipArt)


To convert a raster image into a vector one you will need the following software: Insсape, patch to SCAD, OpenSCAD, and also Repeater-Host for a 3D printer.

  1. Download the necessary programs and supplements.
  2. In Inscape menu choose File -> Open -> Image and click OK.
  3. Select the image, in the Menu click the LOCK icon and enter parameters of the picture at the left side of the LOCK icon.
  4. To convert a raster image into a vector one go to Menu -> Contour (Outline)-> Vectorize raster. In the opened window select two colors. To diminish brightness click Upgrade to preview changes.
  5. Move the image and delete the one, which remained unmovable.
  6. Select the image by means of the tool “Edit levers of outlines and joints” (second item at the top in the left column of the menu).
  7. Then patch the image to OpenSCAD. Enter Menu-> Extension -> Contouring -> Patch to OpenSCAD.
  8. Open the saved file in OpenSCAD and click F6.
  9. Save file as stl. File -> Export -> Export as stl.
  10. In Repetier-Host open the STL model. Tab -> , Place the object (размещение объекта) -> Add the object (добавить объект).
  11. Feed numeric values of the axes XYZ into the ScaleObject Menu so that the model was within the frames of the printer working area and the material. The bigger Z is, the more passes are needed, the deeper and darker is engraving. One layer = 0.07 cm. To change the number of passes unlock the locker.
  12. To change the laser beam diameter at 0,2 mm for denser passes of the laser go to Menu -> Configuration ->Printer Settings -> Tab.
  13. To set the necessary speed of passes go to Slicer -> Menu Configuration -> Speed And Quality. Different materials require different speed. To speed up the transition between letters set TRAVEL to 150. Other parameters set at 10 when you engrave plywood or cardboard. Click Slicing in CuraEngine.
  14. To save the model go to Menu-> Preview-> GCode Editing -> DISKETTE icon.
  15. Open the saved file in Notepade++ and change the code down to the 13th line “Layer count” at the beginning of the code, as seen on the screenshot (a) and up to M107 at the end of the code (screenshot b).
    a)

    ;Generated with Cura_SteamEngine 14.12
    ;Default start code
    G28 ;Home extruder

    M107 ;Turn off fan
    ;Absolute positioning
    ;Extruder in absolute mode
    ;Activate all used extruder

    G92 E50 ;Reset extruder position
    ;Wait for all used extruders to reach temperature

    b)

    G1 F2400 E633.50589
    G0 F9000 X143.040 Y107.202 Z20
    ;Default end code

    M107 ;Turn off fan
    ;Disable all extruder
    G91 ;Relative positioning
    T0

    G90 ;Absolute positioning
    G92 E0 ;Reset extruder position

    The more layers are the deeper and darker is engraving. Normally, 2 layers are enough. In this case the code after LAYER 2 is deleted.

  16. Z coordinate (the height, on which the laser focus depends) is to be set by yourself. To set it open Change by clicking Ctrl + F.
  17. Insert SD-card into the printer, set the coordinate axes to 0 (home state) and enjoy engraving.