Rules | Design | Check Your Design | Choose Your Color | Submit Your Design | Pick Up Your Print


Only Northbrook Residents with a Library card in good standing may submit designs for 3D printing, and only one job may be submitted at a time. View our complete list of rules.

Design Your Object

There are sites such as Thingiverse that both give away and sell the design used by the printer to build. You can either use the designs as you find them, or you can use programs to modify them. You can also use design software, much of it free, to create your own pieces.

Blender is very powerful free software, but takes a while to learn.
123D Design is much simpler to use while still being a robust system.
SketchUp is a simple application with a fast learning curve and good tools.
Tinkercad is an online tool that has great tutorials and is very easy to use.

Some Considerations When Designing

Design Specs: In most design software, it is prudent to work in millimeters rather than inches.

Scale: Be aware of the final size of the object you will be printing. Think about how large the final print will be. Don’t put too much geometry in a spot that will only be a few millimeters across.

We have a limited printing area (10.5” L X 5.7” W x 5.6” H, or 266.9 mm X 143 mm X 145.3 mm), so scale your work accordingly. In the email that you send in, give a size indication in millimeters of the dimensions of the object. Designs should be scaled to those dimensions. We are unable to print objects that take more than 10 hours.

Turn off smooth shading while modeling: Smooth shading is controlled by your software and hardware and changes the look of the geometry. Use a faceted shading method that allows you to see each polygon explicitly. This is how your model will look when printed.

Closed Geometry: All the objects that make up your model must be closed or “watertight”. Overlapping geometry works fine as long as there are no unattached edges. (We can easily Boolean a large amount of objects at once.)

Feature size: In general, long thin features are difficult to print. Use this rule of thumb: for every 1mm of length a feature should be .5mm thick. So, a 5mm long robot’s antenna would need to be about 2.5mm in diameter to survive once printed.

Structural integrity: Will your model be able to support itself? Beware of chicken-like proportions: a large body supported by thin legs. The legs could easily break during shipping or from the weight of the heavy body. Objects are built up in layers and thin pieces have better strength if they are printed horizontally rather than vertically.

We can’t print in air: The Replicator 2 is best at printing objects designed from the ground up. Objects that contain extreme overhangs — where large parts of the object are suspended in mid-air, or pieces that extend out at more than a 45° angle  — will not print as well as objects without overhangs.  Printed objects that have overhangs will need to be printed with supports which you will then need to break away from the piece. This may alter its look. You are responsible for removing the supports. Be aware that supports may alter the exterior texture of the object.

.STL Files Only: Our 3D printer only understands explicit geometry. All files that we use are in the .STL format.

Check Your Object

We strongly suggest that you use a program such as Netfabb to check and repair errors in your designs. It will catch problems that look ok to the eye, but will cause builds to fail. Once repaired, save the fixed file.

Choose a Color

We have a limited number of colors and the selection changes over time. If you want a specific color, ask when you submit your file. We won’t print a single piece in multiple colors, but some multiple piece projects can be printed in different colors.

Common color choices include: White, Clear, Black, Red, Gray, Green, Blue.

If you want a color that is not supplied by the Library, you can donate funds to have the Library purchase it.  Please indicate this in your email to us and we will contact you with further instructions.

Submit Your Design

Send an email with “3D Print” in the subject line to with the .STL file of the object attached, the desired dimensions of the completed object, your name, Northbrook Library card number, and your preference of color. Please be aware that:

The Library will endeavor to print quality objects for submitted files, but we cannot guarantee that the files will print the way you want. Use of the Makerbot 2 is meant to foster learning and imagination. If you need something to be exact, use a commercial printer.

Design Responsibility: Staff will make a cursory review of submitted designs before preparing them for printing. You are responsible for the quality control.

Failed Prints: Prints fail for a number of reasons which may, or may not, be dependent on your design. If your project is obviously failing we will cancel the print unless you specifically ask in your submission form that it continue to finish. This will count as a finished job and you will go to the end of the queue for the next print. We will stop the printing of any job that in our judgment might damage the R2 or won’t yield lessons to fix your next job.

Pick Up Your Print

If no changes are needed, your model will be printed and kept at the Circulation Desk on the first floor for pickup. You will receive an email letting you know it is ready. You can expect models to be printed in about a week but printing time can vary.