Basic Model Preparation with Meshmixer
Digital Media Tutorial
Written by Trevor Williams
Opening your Mesh
After loading Meshmixer from the Start Menu, click on the
Import button. Select the STL you would like to prepare for
3d printing.
If, when you load your file, it is imported in the wrong orientation,
go to File > Preferences. In the File tab, make sure you’ve
checked the Flip Z-Y axis on Import-Export option.
Then reimport your object, selecting the option to Replace as
you do so.
Closing Holes
In the sidebar, click on the Analysis button,
then select Inspector from the submenu.
Select the type of fill based on the geometries of your
model. For most models, Flat will close all faces. For
high-curvature smooth models, Smooth Fill will work
best.
Set the Small Threshold to the smallest holes you want
to fill.
Press Auto Repair All and then Done to fill holes.
Ensuring a Solid or Watertight Mesh
In the sidebar, click on the Edit button, then in
the submenu, click on Make Solid.
NOTE: You must hit the Update button at the bottom of the
interface to see how the changes you’re specifying to your
model change it. Your model will not be changed though
until you hit Accept.
First, set your calculation method to Accurate. If your calculations are taking too long, or crashing, set the
method to Fast. If your calculations are still problematic, select Blocky.
Solid Accuracy sets the number of calculations done to the resulting mesh
to match it to the shape of the original mesh. NOTE: The accuracy increases
directly with this sliding scale. The number of calculations increases
exponentially. Be careful when increasing this number.
Mesh Density specifies the number of times to divide your current mesh faces
so that a smoother curvature can be achieved. Increasing this number will
result in a significant file-size increase, which will increase the amount of time
necessary to slice your model before printing it.
NOTE: 128 on this scale corresponds to your current density, i.e. it will not be
changed. If you drop it below 128, you will have a more jagged mesh. If you
raise it above128, you will have a smoother one.
Offset Distance will offset the resulting mesh by a set distance from the
original mesh. Positive numbers offset out from the mesh surface, and
negative numbers offset the mesh in.
NOTE: If you intend to make interlocking Makerbot parts, offset one of them by
-0.4mm or both by -0.2mm. This is not necessary when printing to the Taz,
Fortus, or Dimension printers.
Minimum Thickness will scan your model for structures below a given
thickness (e.g. columns or narrow walls) and will increase them to the set
minimum thickness. If you are unsure if any of the details in your model are too
small to print, use this option. Set it to 0.6mm for a Makerbot print, 0.3mm for a
Taz print, or 0.2mm for a Dimension or Fortus print.
Cull Edges Threshold reduces your mesh before applying the other
calculations. We recommend not using this, as the results can be
unpredictable.
In the Advanced breakout menu, make sure that Close Open Boundaries is
checked.
When you are happy with the updated results, click Accept to apply the
changes.
Rotating your model to minimize support
In the sidebar, click on the Analysis button, then in
the submenu, click on Orientation.
Set your Overhang Angle to 72.
Set your Strength Weight to 0.
Set your Support Volume Weight to 100.
Set your Support Area Weight to 50.
Press Update to see how these factors have
changed your model orientation.
NOTE: This system will orient your model to
minimize support. It may orient your model in
a way that will make it more difficult to print,
especially if your part is designed to print
without support.
Please only use this method if you intend to
print your model with support.
Rotating your model to
the ground plane
In the sidebar, click on the Edit button, then in the submenu, click on
Align.
Make sure your settings match this example:
Draw a “scribble” on a face or several faces on
the transparent “ghost” model. This will then
cause those faces to be snapped to the
ground plane on your actual model. Drawing
on the actual model will have no effect.
NOTE: If your scribble draws across faces that
are not co-planar, the model will snap to the
average plane between these faces. Make
sure you only draw on co-planar faces to
ensure your part snaps flat to the ground
plane.
Press Accept to apply the new orientation to your model.
Exporting your Repaired Model
Go to File > Export and select your preferred filetype for your repaired mesh, typically a Binary STL.
Keep in mind that your model’s file size will usually be larger than your original file. If your model is too
complex or large to be easily sliced at this point, you can reduce the mesh in Rhino using the ReduceMesh
command.
If you still see problems with your mesh, or the automated changes made by Meshmixer are not acceptable,
please refer to the Advanced Rhino Model Repair tutorial for further advice.