How to: Digital Fabrication with Blender / MakerBot

How to use Blender to make models for 3D printing on the MakerBot Replicator Dual


First steps with Blender

Invoke Blender. Click anywhere to get rid of the intro picture.

Note that there are many windows and that focus follows mouse so be careful where you click or hit letters. Normally your mouse will be in the 3D View window.


  • File User preferences File Auto Save Temporary File
  • File User preferences Input Emulate Numpad

Modes and Models

<TAB> toggles between Edit Mode and Object Mode. You can tell which mode you’re in by looking at the 3D View window header near the bottom.

Z toggles between Solid Model and Wireframe Model. You can tell which model you’ve selected by looking at the picture next to the Mode indicator. You’ll also notice a difference in how any objects in the 3D View are represented.

Deforming the Default Cube: Moving vertices, edges, and faces

  1. <TAB> to get into Edit mode
  2. Click and hold Right Mouse Button (RMB) to select point and move it around
    1. Note that once you start moving you can release the RMB
  3. LMB to leave the point where you want it
  4. Note that this behaves the same regardless of Solid or Wireframe model
  5. Shift RMB to select additional points: Click and release RMB on one point, move to another point <SHIFT> and click and hold RMB; now you have two points selected and so both of then will move
  6. Note that by default you are in Vertex Select mode. You can switch to Edge or Face select modes in the 3D View window header, and now you can select edges or faces respectively.
  7. Play around with this for awhile until you gain some confidence.


Follow the steps above to select a face, but this time, before you click the RMB, press and hold E to extrude.

Note that you can extrude an edge or a vertex, but don’t do this as it creates a zero thickness element that confuses the 3D printer

A few other keys

A toggles select/unselect everything

X deletes whatever is selected: vertices, edges, faces, objects.

Adding Objects

Add Mesh Sphere  or other objects

Objects are placed wherever the cursor is. Move the cursor with the LMB

Practice deforming and extruding these objects

Moving Objects

  1. RMB to select object(s) as always
  2. Press and release R, S, or G to Rotate, Scale, or Grab (to move). Once object is selected simply move mouse.
  3. LMB leaves object where you placed it.

Moving point of view

SCROLL zooms in and out

SHIFT and SCROLL to dolly up and down

CTRL and SCROLL to dolly left and right

SHIFT ALT SCROLL to rotate vertically

CTRL ALT SCROLL to rotate horizontally

Intermediate Blender

How to scale along one axis but not the others

  1. <TAB> to get into object mode
  2. S to scale but before you move the mouse
  3. X, Y, or Z to scale along the X, Y, or Z axis only, respectively
  4. A line appears showing the selected axis for scaling
  5. Move mouse to scale desired amount
  6. Stop with LMB (or <Enter>)

Setting units to Metric or Imperial

  1. On the right hand side of the 3D view are two windows that say “Scene”. The lower one has a picture of a camera and 7 other objects
  2. Hover over the second icon. It should say “Scene”. Click on this.
  3. A bunch of new options appear. The first should say “Scene”, the second “Units”.
  4. Notice that the Units selected is “None”. Change this to “Metric” or “Imperial” as you prefer.
  5. Notice that the units are displayed in the top left corner of the 3D View window. This is also the spacing between grid lines.

Precise Movement and Placement

Method 1: Using the “View Properties” tool panel

  1. Set units to metric or imperial as above
  2. Press N to toggle the “View Properties” tool panel
  3. <TAB> to get into object mode
  4. Select an object. Note that the “View Properties” tool panel gives you the location, rotation, and dimensions of the object selected. You can rotate, scale, or move an object and watch these numbers change.
  5. You can also type a number in any of these boxes in the appropriate box to precisely rotate, scale, or move an object. For instance, to make a cube precisely 2m x 3m x 4m simply enter 2, 3, and 4 in the appropriate boxes in the “Dimensions” section.

Method 2: Using precise translation:

  1. <TAB> to get into object mode
  2. Select an object
  3. As before, G to grab object, but don’t move mouse:
  4. Y to specify motion along the Y axis only (or X or Z)
  5. 10 to specify movement of 10 units (or any other number)
  6. LMB or <ENTER> to fix
  7. Works for R (rotate) and S (scale) as well

This allows you to scale a model to fit the 3D printer.

Joining two meshes to make one objects

  1. Be in object mode
  2. RMB to select one mesh then SHIFT + RMB to select next mesh
  3. In the Properties window, select Object Modifies (the wrench)
  4. Click on Add Modifiers and select Boolean (in the Generate column)
  5. In the Operation box select Union
  6. Select Union
  7. Click on Objects, and select the other mesh object
  8. Click on Apply
  9. Note that this adds a new object to the second object you selected, in the shape of the first object you selected. In other words, the first object is duplicated. In the next step you will Join these two objects.
  10. Press A to deselect all objects, then select both objects (you can use A if these are the only two objects)
  11. Press CTRL + J to join these two objects


    • Misc
      • Red for X, green for Y and blue for Z
      • Blender will not prompt you to save changes. If you forget, use File recover last session
      • Blender uses a “focus follows mouse” user interface model
      • Blender has lots of modes, many of which are explained here
    • Toggling between modes
      • Z in the 3D view toggles between Wire Frame and Solid views
      • TAB toggles between Object mode and Edit mode
    • Changing perspective
      • Zoom with scroll
      • Click and drag with  MMB  to orbit  around the center of the view
      • SHIFT and scroll to dolly up and down
      • CTRL and scroll to dolly left and right
      • To center the view on an object in the scene:
        1. Make sure Blender is in Object Mode.
        2. Zoom out until the object is in the viewport.
        3. If any objects are selected, use  A  (or Select → Select/Deselect All) to deselect them.
        4. Select the object of interest by clicking  RMB  on it.
        5. Press  Num.  to center the view.
      • Moving viewport in OBJECT mode:
        1. Zoom using one of:
          •  SCROLL
          • Click and drag vertically with  Ctrl + MMB
          •  Num+  and  NUM−  (only if NUMLOCK)
        2. Orbit around the center of view view with either:
          • Click and drag with  MMB
          • View -> Navigate -> Orbit
          • use NUMLOCK and NUMPAD (4, 6, 8, 2)
        3. SHIFT and SCROLL to dolly up and down
        4. CTRL and SCROLL to dolly left and right
    • Manipulating an entire object in OBJECT mode
      • A toggles selecting ALL or NONE
      • Select individual object with RMB
      • Select multiple objects with SHIFT and RMB
      • Select object and then G to Grab; mouse moves object; ENTER ends
      • Select object and then R to Rotate; mouse rotates object; ENTER ends
      • Select object and then S to Scale; mouse scales object; ENTER ends
    • In EDIT mode:
      • Choose Vertices, Edges, and Faces mode
      • Select them with RMB; multiple with SHIFT
      • G to Grab; R to Rotate; S to Scale
      • ENTER ends
      • DEL or X to delete (Vertices, Edges, or Faces)
      • Adding Vertices
        • Choose Vertex  mode
        • Select an existing vertex
        • CTRL + LMB  to add a new vertex and a new edge to the selected vertex
      • Adding a face
        • Select all the vertices in the chain, and press F; this will add another edge joining the first and last vertex, and will fill in the loop with a new face. VERY IMPORTANT
      • Extruding
        • Choose Edge or Face mode
        • Select an edge or face
        • CTRL + LMB  to add a new vertex and a new edge to the selected vertex

Check and possibly repair your model before printing

  1. In Blender, fix non-manifolds
    1. Make sure you’re in edit mode
    2. select none
  2. Export your model as file type STL
  3. Analyze, check and repair your STL by running it through NetFabb’s online service. Visit the link to upload your file.
  4. You will receive email when the process is done (minutes); visit the link in the email to view the results. Check the dimensions (Outbox is probably the most useful) and make sure your “Mesh is manifold and oriented”
  5. Download the fixed result
  6. Optional: netfab Studio Basic, a free download, allows you to view your object layer by layer, as it would print.

Working with the Replicator Dual

Using MakerWare to prepare your file for printing

  1. Invoke Makerware and open your file
  2. Open the Makerbots pull-down menu and select Type of MakerBot. Select The Replicator (Dual)
  3. Make sure your object will only the left extruder:
    1. Click on the Object button in the lower left. Click again to open the Object Information box
    2. Click on Select All in the Object Information box
    3. In the middle of the Object Information box select the Left extruder
  4. Click the Make button near the top middle. This will open a new window with various making options:
    1. Make sure Export to a File is selected
    2. Make sure Export For is set to The Replicator (Dual)
    3. Set the Left extruder material to MakerBot PLA
    4. Since we aren’t using the Right extruder, it doesn’t matter what it’s set to
    5. Select Standard Resolution
    6. If you want a Raft, set it to Left Extruder; otherwise set it to Off
    7. If you want Supports, set it to Left Extruder; otherwise set it to Off
    8. You can leave the Advanced Options as they are
    9. Click the Export! button. A new window will open.
    10. In the new window:
      1. Make sure you have selected X3g, SD print for firmware 7.0 or later in the lower right of this window
      2. Change the file name and folder if you wish
      3. Click on Save
  5. Wait while MakerWare slices, verifies, and prints-to-file your object
  6. Copy the resulting x3g file to the SD card and take it to the printer

Preparing the printer

While MakerWare prepares your file, prepare the printer:

  • For best results, before printing, level the build platform. Use the LCD display and the M control panel to find the Level Build Platform option that walks you through the steps.
  • Clean the blue tape with alcohol to help your object stick. Use new tape if the current tape is torn.


  • Use the LCD display and the M control panel to find the Print from SD card option
  • Select your file and print

If the filament doesn’t come out when printing

Usually this is accompanied by a clicking or grinding sound.

  • Use the LCD display and the M control panel
  • Go to Utilities -> Load Filament
  • Unload the filament, cut off a few inches, and the Load it again



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