Creating your own print ready 3D models needn’t be difficult. Here Alastair Jennings takes a look at how to get started with the basics of 3D modeling for print using blender.
What you’ll need
- OS: Windows / Mac or Linux computer
- Software: blender
What you’ll learn
- How to install blender
- How to get blender print ready
- How to create a model
- How to check that models ready for printing
What is blender?
blender is a free 3D modeling application and is part of the large Open Source community. The application is available for most modern operating systems for free, which makes it an ideal inexpensive platform for creating your own 3D models rather than downloading other people’s.
To download visit the applications web site at https://www.blender.org then just select your computer type; Windows, OSX or Linux from the list and start the download, once complete it’s pretty easy to install on all systems.
As a 3D application blender has several different workspaces and modeling options depending on the destination of the models that you’re creating. When you open up the interface for the first time you’ll see a variety of windows, menus and panels.
These different panels and screens are great for animation and screen modeling but ultimately for 3D Printing we don’t need them all.
Before we start on our project it’s a good idea to customise the interface so that it suits our needs as 3D Printers, rather than animators, game designers or architects!
The default user interface for blender shows six different windows:
- Information Window – Bar across the top of the screen
- 3D View Window – Main work area
- Time line – Area below the 3D Window
- Outliner Window – Top right and shows all the objects in the scene
- Properties Window – Below the Outliner Window, this is where we can adjust settings
- Tool Shelf – This is part of the 3D View Window and contains Tools (Press T to make it appear and disappear)
3D View Window – Preparing the interface
Working in 3D is a little different to 2D work and as such the interface that enables you to work with 3D models can initially be a little daunting. However spend a little time finding out what the different interface areas are and what they do and everything will slot into place surprisingly quickly.
If you choose to dive straight into the modelling then at the very least it’s worth knowing that using the following shortcut of ‘Ctrl, Alt Q’ will quickly enable you to switch between a single and a split screen view. Something that is exceptionally handy when working in a 3D environment.
This split view enables you to see the model you’re working on from a variety of angles at the same time. For instance a perspective, side, top and front view. The toggle view feature is quick and easy, and will usually surfice when you quickly want to check a different angle of your model, but if you do feel the need for a little more interface customisation then here’s how.
Customise the interface
If rather than the four way split you’d like to divide screen yourself then grab the small shaded tab in the top right of the 3D View Window and drag it to the left, as you do so you’ll see the Window divide. Now grab the shaded tab in the top right again and drag down to create a screen divided into three.
At the moment it’s all looking a bit crowded as we’re seeing the Tool Shelf appear in each of our window divides. Click into the top right window and hit ‘T’ on your keyboard to hide the Tool Shelf, then click on the window below and repeat.
At the bottom of each of these new windows you’ve created is a menu bar, click on ‘View’ and then select the view that you want. A good starting option is ‘Perspective’ for the large View Window and then a ‘Right Side’ and ‘Top’ view for the other two.
If you want to get rid of any of the Windows just grab hold of the shaded tab in the Window that you want to keep and drag it over the Window you want to remove. As you do this an arrow will appear over the window that will be deleted.
At the bottom of the screen you’ll see the timeline taking up valuable space, as we don’t need the animation features for 3D Modeling we can quickly remove this. Move the cursor between the Timeline and 3D View Window so the icon changes and then right click and select ‘Join Area’. Hover the mouse over the Timeline and a large arrow will appear, click to remove the Time Line.
Getting blender Add-ons for 3D Printing.
As blender has a huge following there are plenty of extras and add-ons that will help you with your 3D modeling. It’s a good idea to get these installed now.
To get the Add-ons and activate, go to ‘File > User Preferences’ (Ctrl, Alt U), and then click Add-ons. The menu on the left shows a long list of options and quite a way down is ‘Mesh’, click and you’ll see the ‘Mesh: 3D Print Toolbox’ that we’re looking for. At the moment this will be greyed out with a small radio button positioned to the right, click into this box to tick. Click ‘Save User Settings’ then close the Window.
Real world measurements
3D modeling has many uses from real world design such as product prototyping to designing for screen. As such 3D applications use a variety of measurements that are handy depending on how you’re using the package. As our final output will be for 3D Printing we need to use a measurement that translates to the real world such as Metric.
Click onto the properties bar and select ‘Scene’. This is the third icon along with a small cube and cylinder, under units select Metric and degrees. Once clicked the units will change from blenders own measurement system to meters. You can at this point change the Measurement scale to cm or mm by typing in 0.01 or 0.001 into the scale box. If you do this you will also need to update the ‘Display settings’.
Display settings can be found by opening the Transform Panel (N) and scrolling down to the display settings and entering in the same details here as you put in the units section.
For simple modelling and if you’re new to blender leaving the unit’s in meters isn’t too much of an issue and will actually make it easier for you to work with the application. At the point where we export the model we can change the scale ready for print.
As default the mouse configuration of blender is a little odd so it’s worth getting this sorted out before you start. To change go to ‘File > User Preferences’ and then click on Input. Click Left under the ‘Select With’ title and then ‘Save User Preferences’ and close the window.
To save down all the changes that you have made to the interface go to ‘File > Save Startup File’. Now each time you load blender you’ll get these settings so you can go straight into modeling for printing.
In this project we’re going to make a temple that’s going to be mounted onto an Electric car that will be raced at Goodwood for the Goblin Challenge.
The model will be created in blender and will be based on the Sandroyd School Temple http://www.sandroyd.org/. Once modeling is complete we’ll then use the Cura software to prepare the model file ready for printing on the Ultimaker 2 Extended.
The Filament we’ll be using is the latest ABS Filament from Verbatim http://www.verbatim-europe.co.uk/en/3D/
We’ll get straight into the modelling by using ‘Shift A > Mesh > Cylinder’ to create the first object. Now change the X and Y dimensions to 5m and Z to 0.2m. Rotate the View so you can see the underside of the cylinder. Switch mode to ‘Edit Mode’ using the Dropdown option positioned at the bottom of the 3D View Window.
Click on the face on the bottom of the cylinder and click the Tools Tab in the Tool Shelf. Select ‘Extrude Region’ and then hit enter without actually extruding. Select ‘Push / Pull’ and give the face a little more width to create a step and click to confirm, for accuracy you can use the down cursor rather than the mouse to extend the step. Select ‘Extrude Region’ again and use the cursor to create a step. Repeat the process to create a series of steps for the temple. Once finished switch back to Object Mode.
Once complete switch the visibility of the steps to off using the small eye icon in the Outliner Window.
Click a new layer (The small box grid of 20 boxes at the bottom of the 3D View Window) and create another 5m cylinder with the same dimensions as before. Now create a Sphere and Cube, make the Sphere with a diameter just smaller than 5m, then make a cube just larger than 5m. Move the Cube so it intersects the Sphere in the middle.
Select the sphere and then from the ‘Modifier’ menu select ‘Boolean > Intersect’. You’ll see the Sphere disappear. Click the Cube and from the Tool Tab select delete. You’ll now see the half Sphere. In the Properties Window under ‘Objects’ restrict the ‘Transform Locks’ and rotate the Sphere 180 degrees and move it to align with the Cylinder. Use ‘Add Modifier > Boolean’ then ‘Operation > Union’ select cube from the object dropdown and click ‘Apply’ to bind the two objects together.
Click on a third layer and create a cube, Cylinder and an Empty. Adjust the size of the cube to make a platform for the cylinder by adjusting the Z axis to 2 and X, Y to 0.3.
Left click to select the cylinder and change the Z axis to 4 and X, Y to 0.6. Now move the cylinder so it slightly intersects the cube.
From the Properties Window select Modifiers ‘Add Modifier > Boolean’ then ‘Operation > Union’ select Cylinder from the object dropdown and click ‘Apply’ to bind the two objects together. From the 3D View Menu select ‘Right View’ and move the Column so it rests on the center line set the X and Y locations to 0.
Click on the ‘Empty’ in the Properties Window and set the Location so that X, Y and Z are all set to 0. Select a Top View so that you can see the next stage as we create the columns.
With the Cylinder selected click ‘Modifiers’ in the Properties Window and select ‘Array’. Increase the count to 10 and untick ‘Relative Offset’ and tick ‘Object Offset and select ‘Empty’.
As soon as you do this the array is created around the ‘Empty’ what you’ll find will happen is that each duplication of the Cylinder will vary in size. To set all to the same size in the 3D View Menu go to ‘Object > Apply > Scale’.
Now check the model from all views by using the screen toggle (Ctrl, Alt Q) before continuing. You may find that you need to adjust the Z position of the ‘Empty’ slightly so that all cylinders are sat on the base line.
In the ‘Properties Window’ select Object and ‘Transform Locks’ and make sure you lock the X and Y. Select rotate and rotate the cylinder to create a circle. To straighten the cylinder bases click the Original Cylinder and rotate on the Z axis.
Select the Y axis arrow to adjust the columns so that they’re evenly spaced and in a circle. Hold down Shift and switch the visibility of the steps model layer back on. You can use this as a guide to position the columns. Make sure the Columns rest on top of the steps. At the moment the size of the steps may be a little small, so use ‘Scale’ to adjust.
Switch on the visibility for all the layers. Select the steps and go to ‘Modifiers’ and create a ‘Boolean > Union’ between these and the columns. Then repeat for the columns and dome. Finally check the model for any objects that are left over from the Union process.
Finally click on the ‘3D Printing Tab’ in the ‘Tool Shelf’ and click ‘Check All’, scroll down to the bottom of the window and you’ll see if there are any issues. As this is a relatively simple model you shouldn’t have too many problems. The first time you click it will highlight some problems with ‘Manifold Edges’, so just click ‘Make Manifold’ and ‘Check All’ again.
If you’re model does show that it has Manifold edge first ensure that you have deselected your entire model by hitting ‘A’ on the keyboard. Once de-selected, hit ‘Ctrl, Shift, Alt and M’, some vertices will now be highlighted in orange. These highlights are non-manifold and need to be fixed before printing.
The easy way to fix these non manifold faces is to hit ‘F’ or click ‘Make Manifold’, if this doesn’t do the job then you’ll have to manually plug the holes by selecting the surrounding edges, holding down ‘Ctrl, F’ and selecting ‘Fill’.
At the moment we’ve created the model without paying too much attention to the dimensions so if we were to print it would measure well over 5 meters across. Change the dimensions to cm and then set the location of X, Y and Z to 0.
Now make sure that the model is saved and click Export, this will export your models as a STL file ready to open in Cura and print. If you haven’t already, download Cura here
finally… here is the final printed model!
In The Classroom
This tutorial makes a great starting point for introducing blender as a free 3D modelling tool. It provides a guided task allowing them to learn the key features of using this software.Simply provide a link to students, who can follow the step-by-step instructions in the tutorial at their own pace to make the temple model. Following on from this students should have all the basic skills required to start to design their own models using this software.