Mechanical Engineering - 3D Printing

Here are a few guidelines for better model designs.

• 3D printing using fused filament fabrication (FFF) cannot be made in empty space. An adequate support structure (scaffolding) must sometimes be added. Printers can calculate this scaffolding and build it, but this is not the most reliable method. Reposition your model so as to have it lay on the print bed. Hollow models must also be filled with a support structure or include a sufficiently thick double wall. Support structures are usually easy to remove, but more complex or highly detailed objects may be difficult to clean.

• Opt for simple shapes and right angles. An object that includes a projection at an angle greater than 45° from its base needs a support structure and risks becoming deformed during printing.
  

• Choose free or affordable professional software. This way you won’t have to learn a new, more complicated tool when you’ve reached the limits of the more basic tools. For your personal projects, avoid industrial software, even if you have access to these tools at Polytechnique or at your workplace. Such tools use exclusive file formats, which will prevent you from modifying your model once you no longer have access to the software.

• If parts are to fit or be printed together, adjust for a tolerance of at least 0.25 mm on either side.

• Find help from colleagues, forums or groups.

• Use a model repair software before printing, such as the one included in Autodesk Fusion 360. This will correct small design errors such as incomplete surfaces or crossing lines. Ultimaker and MakerBot software is also useful to assess the printing time and the object’s final weight.

• Get to know your printer: print various forms with different parameters and study the results.

• Don’t give up. Your first printed objects will probably not come out as planned. A lot of trial and error is required to understand and calibrate your printer.

• Read the manufacturer instructions for your printer and follow them.

• Some materials may be toxic or even release toxic vapors during printing. Choose one that is safe according to your object’s intended use and make sure the area around your printer is well ventilated.

• Study the characteristics of the material you plan to use, such as weight support or heat resistance. A part that breaks may cause injury or damage. You are responsible for the safety of the objects you create.

• Make sure to properly calibrate your printer and level its bed before each print job.

• When printing with plastic, cold may deform parts or prevent layers of plastic from fusing together. Avoid drafts around your machine and increase room temperature, especially if your printer does not come with a heated bed.

Did you know? Your library offers low-cost 3D printing services!

Loyal to our mission to support teaching and research, we want to make this innovative technology accessible for its high educational and social potential.

Visit the 3D Printing page for more information.