Three-dimensional printers can save you a lot of time and money, but if you are unaware of some of their complexities, you may not get exactly what you expected out of the machine when you pick up your models at the end of the day. From working with your original CAD file to making it suitable for 3D printing, importing it into the printer’s software preparing your digital file, to finishing off the part at the end of the process, the actions you take in each step can have a significant impact on your model.

Eliminating unnecessary geometry can help speed up the process. For example, consider leaving the engine under the hood of a car out of the file preparation when printing. The engine as well as items such as the screws inside of the car can slow down the system.

Guidelines
As a general rule, all geometries must be able to exist in the real world. All geometric parts have a minimum wall thickness. For functional walls that hold parts together, it must be at least 1 to 2 mm. Minimum feature size resolution can be as low as 0.1 mm for ornamental features such as raised text or a font size equal to four.

File preparation
As an option, remove unnecessary geometry. This helps the system operate faster because it shrinks the file size. For example, you might not need to visualize certain parts on the inside of your model, such as an engine under the hood of a car. Or, when you are only concerned with one area of the design, you might want to remove the detail on the backside or any other unnecessary external feature. Printing these parts can also consume additional system resources. However, this step is optional and depends on the application. Oftentimes removing the parts is more difficult than dealing with a slow system.

Once you export the file out of a CAD program, check it thoroughly and fix any problems. Make sure the file contains only solids and eliminate features that register only as surfaces. For example, tabletops may lack a thickness dimension, so a 3D printer will not print them. An object may look solid from afar, but as you zoom in, the sides may not be completely closed. Unless you check files before printing, you could end up with a model that is missing features that appeared on your screen and in your file, but did not print. For example, many tabletops in houses are one-dimensional; they do not have any thickness.

Because file checking can be complex as well as critical to a successful print job, some 3D printer manufacturers now offer software packages that execute this task. The ZEditTM Pro, for example, checks files automatically upon importation and fixes those that it can fix without your intervention.

Size your part appropriately. If necessary, split the model in half. Some printer systems will help you build orientation pins to accommodate this action. If you are using a process such as Z Corp’s, and the model is too big, our printers will let you create holes so as not to use too much material.

Know the capabilities of your printer. Z Corp’s printers not only add color; they print labels, dates, filenames, logos, and annotations.

Know your options
Our software lets you to add color to different parts of your assembly or color each part individually to help illustrate a point or to highlight an internal piece. In addition, the printer can apply a virtual sticker to the model. You can add labels, print a filename, date, owner, logo, or annotations on the part to help with traceability.

Print it
As you move your file from the preparation software into the printer driver, position it properly for the printer. The slowest direction is vertical. Lay things on their side for faster printing. Also, put multiple parts in one build.

Structural walls that hold the model together typically have higher tolerances than ornamental features, such as raised text.

Finishing your model
It is helpful to infiltrate parts as they come out of the machine. An infiltrant is another resin that will
impregnate the part to help strengthen, solidify, seal, and improve its appearance as well as enhance the color. It is important to pick the correct infiltrant. The choice depends on whether the models will be for visualization or as functional, end-use parts.

Z Corporation
www.zcorp.com

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