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TechHub: 3D Printing @ TechLab

3D Printing @ TechLab

two technicians working in 3D printing lab

3D Printing @ TechLab

The Caltech Library Techlab provides members of the Caltech community hands-on access to innovative rapid prototyping technologies to support the Institute's research and educational mission.

Students, faculty, postdocs, and staff can now register for open access to our 3D printing equipment. We provide new user training and materials needed to create prototypes of 3D models. Previous experience with the equipment is not required.


Register for new user training


Slicing Your Model

The general 3D printing workflow starts with a 3D model, exported as an .STL file, which is then put into software (Cura) that slices it into layers and outputs a GCODE file. GCODE is basically a set of instructions/toolpaths for the machines to follow.

​Cura is one of many applications (Simplify3D, Slic3r, MatterControl, etc) that slices your STL into layers and converts it to printer-specific GCODE. Cura is a free, open-source software which can be installed and downloaded here:

Installing Custom Printer Definitions

  1. Download 'crafbot.def.json' file here:
  2. Add our custom Cura definition file 'crafbot.def.json' to Cura's 'definitions' folder:
    • Windows: C:\Program Files\Ultimaker Cura <version #>\share\cura\resources\definitions
    • Mac:  Run Cura > Click "Help" on top left > Click “Show Configuration Folder”  > Browse to "definitions" > copy in definition file and close Cura
    • Linux: Copy [printername].def.json files into ~/.local/share/cura/4.9.1/definitions (In Terminal, cp -a [location saved]/definitions/. ~/.local/share/cura/4.9.1/definitions)restart AppImage
  3. Run Cura


Adding Printers to Cura

  1. Go to Settings > Printer > Add a non-networked printer...
  2. Scroll down to CraftUnique > CraftBot Plus
  3. Add Printer


Extruder Settings

  1. Go to Settings > Printer > Manage Printers
  2. Select CraftBot Plus > Machine Settings
  3. Go to Extruder tab on the right hand side
  4. Under Nozzle Settings > Compatible material diameter > Set to 1.75mm > Close


Using Cura

  1. Load your STL or OBJ file
  2. Manipulate your model as necessary (rotate, scale, etc)
    • NOTE: Our profiles have been preloaded with optimized settings designed to work well for most prints.  Please do not alter them until you familiarize yourself with how our printers operate.  
      • Recommended Default Settings:
        • Layer Height: 0.2mm
        • Wall Thickness: 0.8 mm
        • Infill Percentage: 20%
        • Print Temperature: 215° C
        • Bed Temperature: 60° C
        • Print Speed: 45 mm/s
  3. Click 'Prepare' (bottom right corner)
  4. 'Save to File/Save to Removable Drive' (save as GCODE)

For a more thorough overview, please refer to the in-depth guides located at the Ultimaker Cura website: