Frequently asked questions about 3D printing

What is 3D printing?

Image of 3D printed dinosaur skull

3D printers use digital models to fabricate three-dimensional objects one layer at a time. The process has been used in engineering and commercial settings for almost 30 years. Low cost 3D printers, do-it-yourself kits, and open source software are bringing the technology into broader use.

What is 3D printing (3D Hubs)

Zortrax Knowledge Base

Why is the library offering this service?

We endeavor to provide the latest technology and tools to enhance research and experiential learning.
3D printers are already starting to be used in departments and programs on campus (such as architecture, engineering, entrepreneurship, information science), but many students and disciplines do not have access to this technology.  

How do I find a model to print?

See our 3D modeling resources page for links to websites where you can search for free 3D models to print or modify.

How do I create my own model to print?

You can design your object in any 3D modeling software, such as AutoCAD (free for students and faculty through the UA Software Licensing program). There are also many free software programs available.

3D modeling for beginners (Shapeways)

How do I make a solid model (Rhino)

How to fix and repair your 3D files (Shapeways)

Tips for designing 3D printed parts (UT Austin Innovation Station)

Printing tips from Zortrax

Can I meet with someone?

Unfortunately we are not able to make in-person appointments. Our 3D printing service is managed by a team of staff and students, so if you send your questions to 3d@lib.arizona.edu we will make sure to answer them within two business days. For in-person help, you can visit the OSCR Multimedia Zone on the first floor of the Main Library (see link for hours).

File format

Export your model as a stereolithography file, with an STL extension (.stl).

Dimensions

Maximum build volume is 200 x 200 x 180 mm. Layers must be at least 0.1 mm thick.

Units

We recommend you build your model in millimeters. Or convert to millimeters before submitting the final file.

Resolution

The standard resolution is .19 mm per layer, with "Low" infill. We are also able to accommodate .14 mm resolution and .09 mm resolution prints. You can specify a different resolution level by making a note under "Special Instructions" on the submission form

Infill

Our standard infill is "Low", which saves in material cost for the customer. We are also able to accommodate prints in "Medium", "High", and "Maximum" infill. You can specify a different infill level by making a note under "Special Instructions" on the submission form

Multiple parts

If your model includes multiple parts, make each as a separate STL file. You can submit each model as part of the same print request.

Make a solid design

The surface of your 3D model must be watertight. This means all faces of the object must construct one or more closed volume entities. Gaps or holes in the model will cause it to print incorrectly.

See Rhino's How do I Make a Solid Model.

Delete 2D elements

Your final model should not contain any 2D elements, as they can cause naked edge problems. Delete any 2D elements that were used to create sweeps, lofts, or other complex shapes.

Geometry check

Check your design for holes, gaps, or other problems before submission. Numerous third party tools can help you fix geometry problems, including:

  • NetFabb - provides a cloud base service and free downloadable software that can check you files
  • MeshLab - open source software for checking files
  • MakePrintable – free browser-based software for repairing your 3d files and preparing them for
    printing.

Shapeways offers a tutorial for fixing and repairing 3D models using these services.

Common problems

Other things to be careful of when creating your model:

  • degenerate faces - Mesh faces that have 0 area
  • zero length edges - Edges with no length, created by degenerate faces
  • non manifold edges - Faces that have more than one face connected to a single edge
  • naked edges - A surface or polysurface edge that is not connected to another edge
  • duplicate faces - Identical faces in a single mesh
  • faces should be flipped - The faces in a mesh object should point in a consistent direction
  • disjoint pieces - Mesh objects that do not connect but are considered a single mesh

Submitting your model

Once your model is ready to go, make a 3D printing request and upload your STL file. We'll contact you within two business days with an estimate for the cost and turnaround time and also let you know if there are any problems with the file.