3D Printing – PB FAQ

Guided 3D Printing provides a quick and cost-effective way for students to create, iterate, play, and invent. Below are some common questions (and answers) for using the Guided 3D Printing service.

Frequently Asked Questions

The PrintrBot 3D printer uses a process known as Free Filament Fabrication (FFF) where a plastic filament is heated and selectively extruded from a print head nozzle to form layers of plastic. These layers of extruded plastic create a 3d object, much like building a stack of pancakes or a layer cake.
Come to the lab when a consultant is scheduled and bring your part (STL file) on your flash drive and we’ll help you through the rest. Printing is first-come-first-serve.
No. There are very few PrintBots available so it would not be fair for one person to use more than one at a time.
As long as the 3d print is started before the last consultant end of shift. You can come back the next day to pick up your parts.
If all the 3d printers are busy and none will finish before the end of the day, you will have to come back another day.

Guided 3D Printing  Hours

We do not queue parts beyond the end of the day. Each day is a new start.
No, PrintrBot 3d printers are first come first serve.
Yes. As long as all of the the parts fit on one build plate.
MLibrary PrintrBot Play 3d printers are loaded with PLA plastic.

Polylactic Acid (PLA) is a plant-based, biodegradable plastic. PLA has a low melting point, gives off fewer fumes than ABS plastic, and it tends to warp less. PLA  has a shinier appearance than ABS, which is typically more matte in appearance.

Unlike ABS, which bends under pressure, PLA tends to snap. (It is, however, quite a strong material!) For more information, the UM3D lab has Material Safety Data Sheets (MSDS) on all of the materials used in our lab.

The printing area is 4″ x 4″ x 5″ on the PrintrBot Play. For best printing, however, we suggest going a little smaller.
Yes– to an extent. Imagine a model of a person standing straight up with their arms to their side. The PrinterBot could print this without problem, layering plastic layers on top of each other. Now imagine a model of a person with their arms out to their sides. The PrintrBot could print this, too, but only if supports are turned “on” when preparing a model in the Cura software prior to printing.


The supports created by the PrintrBot will usually snap right off. Using a sharp X-Acto knife, needle nose pliers, or snips seems to work best to remove a raft from the bottom of your part. (Should you do this, work carefully and with caution!) Additional plastic can then be sanded or filed off.

If you want to print cleaner overhangs, consider using using the 3DLab’s Dimension Elite FDM printer; it prints supports using a separate material which dissolves after printing. (No trimming, cutting, or sanding required.)


There is a computer in the UM3D Lab near the middle of the lab that is delegated for PrintrBot use; it has the Cura software pre-loaded on it. This computer is available during UM3D Lab hours.
First, look at your CAD model and look at its edges– does it look “closed”? Are the edges showing the ‘interior’ of the object? (Imagine a smashed cardboard box where the edges don’t meet up.) If so, this will be a problem for printing: re-work your part to have closed edges, or consult your program’s help menu.

Some programs like Rhino allow you to see if your part is closed, or watertight– if it is, chances are it will print! For more information on how to fix or alter parts, check out the UM3D Lab’s Magics tutorials

Prepare your parts for 3D printing!