3d printing a cube inside a cube - shaftesbury graphics...the small cube in place in the centre, but...

We are going to do the CAD (Computer Aided Design) drawing for one of these hollow cubes with a small cube inside. The larger hollow cube is 25mm square and the smaller cube inside is 12mm square.

3D printing allows you to easily make something with one object inside another – it would be very difficult to make this using other traditional manufacturing methods. The next slide tells you how this is possible with 3D printing.

3D Printing a cube inside a cube

Diane Burton, STEM Outreach. [email protected] 1 of 6

You can see the hollowed out large cube with a hole through each face of the cube and the small cube sitting inside.

The small cube is place in the centre of the larger cube and when the object is 3D printed, the 3D printer builds special support material around the small cube to keep it in place in the centre.

You can see that the support material is an open lightweight mesh of material just strong enough to keep the small cube in place in the centre, but lightweight enough to be easily removed.

The support material is simply pulled away with a pair of long nosed pliers, leaving the small cube inside the large cube, as pictured above.

CAD drawing of the cube in a cube design

3D printed cube in a cube with the support material still in place

Finished cube in a cube – support material has been pulled away


Using Primitives Box tool draw a box Length 25mm Width 25mm Height 12.5mm

Use Modify Shell and hollow out the shape with a wall thickness of 2mm

Save your work now and remember to keep saving after each step

Below are written instructions to do the CAD drawing for the Cube in a Cube on Autodesk 123D Design CAD software.

Before using the written instructions, it is very helpful to watch this video screencast of the CAD drawing actually being done in the software. Click this link for the video instructions


http://www2.warwick.ac.uk/fac/sci/wmg/about/outreach/3d_design_printing/cad_tutorials/cube_in_cube_video_final_version.mp4

Left click the shape to select it On the keyboard do Ctrl C followed by Ctrl V to make a copy of the shape

Select this arrow on the ‘Move’ handle and drag the duplicate shape to the side

You now have 2 copies of the shelled out box as above

Use Combine Merge tool to make the snapped object into a single object

Select one part as Target Solid and the other as Source Solid – then press Enter and you will see that the shape has merged into a single combined shape as below


Select the Snap tool, then click on the top face of the first shape, then the second shape - watch them snap together so your shape looks like this

Use the ‘Primitives Cylinder’ tool to draw a cylinder with a diameter of 15mm – make sure you get the correct radius for your cylinder. In this case, the length doesn’t matter, as you will see in the next steps.

Click on ‘Snap tool’ then the end face of the cylinder, then one of the faces of the cube. The cylinder with snap onto the cube face - by default it snaps to the centre which is where you want it.

Firstly, ensure the ‘grid snapping is OFF’ - should be crossed through as here.

About grid snappingIf grid snapping is ON, when you snap one object to another they become one object, so you can’t move each object independently. In this case you need to be able to move the cylinder to push it through the cube to cut the hole, so grid snapping must be OFF.

Click Construct Extrude then on the drop down box ensure ‘Subtract’ is selected.

Select the end of the cylinder and push the cylinder right through the cube to cut the 15mm diameter hole

Repeat this process until you have a hole in each face of the cube


Use Primitives Box to draw the small cube 12mm square.

Use Snap tool to snap small cube to top of big cube –ensure Group Snapping is OFFso you will be able to move the small cube down into the big cube.

Select the top cube, and when the options bar appears below, select the Move tool.

Use the Up/Down arrow to move the cube down - it must be in the centre of the big cube so the support material builds evenly. See the diagram below to work how much to move it down by so it is exactly in the centre.

2mm wall thickness

2mm wall thickness

12mm height of small cube

25mmTotal height of big cube

How big will each of these gaps be?– remember the total height of the cube is 25mm

You need to move the small cube down this distance so it sits in the middle of the big cube Now use Modify Fillet or Modify Chamfer

to decorate the cube edges.


3d printing a cube inside a cube - shaftesbury graphics...the small cube in place in the centre, but...

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