This tutorial explains how to design and model a simple 3D-printable coffee mug, by using basic 3d shapes. The intention with this tutorial is to introduce 3D-Modelling to new users, and walking them through modelling their first 3D-object. Software used in this example is Siemens NX, but modelling approach and method are applicable to all available 3D-Modelling software. Also check out Coffee mug design part 2 and part 3 which introduces more advanced tools like sketching, extrude and revolve to be able to control and refine the shape of your design.

Basic steps

  1. Create a new part file
  2. Insert a cylinder with main dimensions for the mug
  3. Shell – Using shell to create basic shape for the mug
  4. Blend – Use blend to round sharp edges
  5. Chamfer – Use chamfer to create angled edges
  6. Color – Use Edit Object Display to change appearance of objects
  7. 3D-Print – Export geometry for 3D-Printing
  8. Modifying design by changing parameters of objects and design features in model history
  9. Draft – Use Draft to create a conical shape of the mug.

For instructions on 3D-Printing, check out this post. For more advanced control of the shape, and creating a handle. Part 2 are introducing sketch and extrude to give you more control on the shape and add a handle. Part 3 are introducing revolve and sweep to give you even more control on the shape and some smart tools further to optimize the model for 3D-Printing. Before starting this tutorial make sure to activate the NTNU Basic role to get the customized and simplified menus.

Activating NTNU_Basic menus

Create new part file

  1. Create a new part file by clicking the New-file icon (Ctrl+N)
  2. Select Model as part template
  3. Give the model an explaining name
  4. Set save location to something smart like your home folder so you are able to fine your files again.
  5. Click ok to enter the 3D-Modelling interface.
  6. If menus looks unfamiliar, make sure to set the NTNU Basic role as explained above.
Creating new part file
3D-Modelling interface

Cylinder – Main body

  1. Select Cylinder on the top menu
  2. Here you can specify direction vector and insertion point for the cylinder. Usually Z-vector and origo [0,0,0] are selected by default.
  3. Specify main dimensions. Set diameter to 75 mm and height to 100 mm.
  4. Click Ok or Apply to create the object.

Shell

With the main body (cylinder) created, you can now start to add design features.

  1. Select Shell on the top menu
  2. Select the top surface on the cylinder
  3. Enter 5 mm shell thickness
  4. Click Ok add the design feature to your model
Shell

Blend

Edge blend can be used to round sharp edges.

  1. Select Edge Blend on the top menu.
  2. Select edges as shown in picture.
  3. Set radius to 2 mm
  4. Click Apply to update your model and keep the Edge Blend menu open
  5. Rotate your model and select edge inside your mug at the bottom. Set radius to 5 mm and click Ok to update model and close the menu.
Rounding sharp edges
Rounding sharp edges

Chamfer

Similar to Edge Blend, Chamfer can be used to add an angle to edges.

  1. Select Chamfer on the top menu.
  2. Rotate your model and select edge on outside bottom of you mug and chamfer the edge 2.5 mm.
Section view of basic mug showing rounded and chamfered edges

Color

Modern design tools have several ways of visualizing models and objects. From simple colors to distinguish object from each other to advanced materials, lightning, shadows and photorealistic renderings and animations. To change color and visualization style of the mug Edict Object Display can be used.

  1. Select Edit Object Display (Ctrl+J) on the top menu.
  2. Select the mug and click Ok.
  3. Select a color from the palette and click Ok
  4. Click Ok or Apply to change color

3D-Print

The mug described in this tutorial is very well suited for 3D-Printing. To be able to 3D-print the mug, the 3D-geometry has to be converted to machine code (Gcode) with slicer software and sent to the 3D-printer.

  1. Select stl Export available in the Manufacturing menu.
  2. Select geometry to export and click Ok. Geometry will exported and placed in the C:\Temp\ folder by default.
  3. Start the slicing software. In this case PrusaSlicer and import the file.
  4. For instructions on 3D Printing, check out ***this post*** for 3D Printing on Manulab.

Modifying the design

3D-Printing can take some time. While waiting, time can be spent on developing and refining your 3D-Model. You may already have noticed the Part Navigator on the left side of your menu bar. All objects and design features created in your model will be added to this list. Cylinder, shell, edge blend and chamfer are all present in the model history. To modify size of your mug it is most convenient to modify the base geometry. In this case the cylinder dimensions.

To modify cylinder dimensions:

  1. Right click (or double click) on the Cylinder object in Part Navigator and select Edit Parameters
  2. You will now enter the Cylinder dialogue box again and be able to modify dimensions.
  3. Modify dimensions and click ok to make changes effective.
Modyfing main dimensions

Similar to modifying the cylinder dimensions, the thickness of the mug can be changed by editing the shell design feature. Edit the shell design feature and change thickness to 20mm. As you may have noticed, object and design features in the model history are dependent on each other. when shell thickness is changed, rounded and chamfered edges are automatically adapts to the new base geometry. The model history is a timeline of your model and as a general rule changes to one object only affect the object itself and object added below/later in the timeline.

Further design refinenment

Roll back to the initial design dimensions. Cylinder diameter 75mm, cylinder height 100mm and shell thickness 10mm. You can do this by modifying the values again or press undo (Ctrl+Z) to roll back. Now you are going to give the mug a conical shape by modifying the cylinder with the draft command.

  1. Right click the Cylinder object and click make current feature.
  2. All objects below cylinder now turn grayish and cylinder is the only visible object. This means all new design features will affect the cylinder directly and will appear right below the cylinder.
  3. We are going to use Draft to give the cylinder a conical shape. Draft commando is not available on the menus, so search for Draft in the search window and start the commando.
  4. Select bottom of the cylinder as stationary face
  5. Select cylinder surface as draft face
  6. Enter draft angle. Start with a small angle like 10 degrees and modify later if you wish. To switch draft direction change to -10.
  7. Click ok
  8. You should have now a conical shape instead of a cylinder. Also note the Draft design feature directly below the cylinder object in your model history.
  9. To make the rest of the design features active again, right click on the last line and click make current feature.
Make Current Feature
Draft

Final results