Custom Supports in Meshmixer

Whilst makerbot automatically generates support material, it can be inefficient and hard to clean. This guide will show users how to create customized support material through meshmixer.

Download Meshmixer here : http://www.meshmixer.com/download.html

0.0 When to use Tree Supports

Support material is necessary to print overhanging elements within a model. Most FDM printers generate a lattice or grid support structure. These structures are beneficial because they are universal. However, if only points of a model are beneath the overhang threshold, tree supports can be used.

Tree supports are adjustable support structures which are most commonly found in SLA (resin) printing. Tree supports are point supports. This means they are most beneficial if only a small portion or point of the model is beneath the overhang threshold.

The potential advantages of using tree supports are:

  • More control over support placement

  • Possible shorter print times with less filament wastage.

Figure 0.0 - The Thinker Printed Using Tree Supports

* Tree supports may not be the best form of supports for long overhanging areas or bridges. These supports are intended for use as point supports.

1.0 Supports in Makerbot Print

Lattice Supports can easily be generated in slicing software such as Makerbot Print, simply by ticking [SUPPORT] under [PRINT SETTINGS].

As shown in Figure 1.0, these supports may be unnecessarily extensive.

Figure 1.0 - Supports in Makerbot Print

2.0 Generating Tree Supports in Autodesk Meshmixer

Autodesk Meshmixer is a free software which can be used to generate smart or tree supports. A model which has been exported from Rhino3d or a similar software as an .stl or .obj can be imported in to Meshmixer.

2.1 Importing a Model in to Meshmixer

In the main menu in Meshmixer, choose [import] and select your .stl.

Figure 2.1 - Import your Model in to MeshMixer

2.2 Analysing Overhangs

Go to Analysis > Overhangs.

To start, we recommend an angle threshold of 45°. This support angle refers to the degree a printer is capable of printing without generating supports.

Figure 2.2 - Analysing Overhangs

Angle Thresholds

In general, the larger the angle threshold, the more supports will be generated. An angle threshold of 0° will mean that no supports will be generated, whereas an angle threshold of 90° will mean a layer completely on top of the last will require supports.

2.3 Generate Supports

Generate supports by selecting [1] Generate Support. In our scenario, a singular support has been generated at the base of the Thinker's knuckles.

Figure 2.3 - A singular and minimum support has been generated at the base of the Thinker's knuckles

3.0 Comparison of Grid and Tree Supports

Printing with tree supports can result in significant reductions in print time and filament usage. In this case, filament usage was reduced by 12% (from 16.71g to 14.74g) and the print time was reduced by 18% (from 1h 32m to 1h 16m). These savings can add up for larger prints.

The tree supports also resulted in less scarring on the surface of the print.

Figure 3.0 - Grid vs Tree Supports: A Comparison

4.0 Other Resources

The following webpages may also be of use when considering smart supports.