The University of Alberta has a very exciting pilot project where they let students use 3D printers for free (this program is provided through the Shack, the Science Hardware Makerspace)! The last time I tried 3D printing, I made a replica of a carbon nanotube but this time I wanted to make a structure that was more rigid. I wanted to see how the 3D printer operates when producing thicker objects. Another difference from last time is that I am using CATIA V5 instead of SolidWorks software to create the 3D model.
A big thank you to the volunteer at the Shack, Tristan, for helping me with the print. I am happy to say that I was much more familiar around the machine this time compared to my first attempt. For a video of how to operate the 3D printers at the Shack, please see this very informative video. It is absolutely mesmerizing to see the printer in action! You might notice that the printer changes the direction in which it applies the plastic for each layer. This helps make the material properties of the part less anisotropic (meaning having different material properties along different directions of the part). It has been shown that changing the direction of printing produces a stronger part than printing in only one direction. The printer was set to print the part using a hexagonal pattern. Even though the 3D computer model is a solid part, there were void spaces in the actual 3D printed part. It is possible to control how much void space is in the part by setting the infill percentage. By increasing the infill percentage, the size of the hexagons are reduced and a greater number of hexagons are printed in each layer. A greater number of hexagons per layer reduces the amount of void space in the part. This website has a great picture showing the effect of changing infill percentage.
Unfortunately, the last portion of the print was completed overnight and no one was there to see what caused the finished product to have holes on the surface. However, I would use an educated guess and say that the infill percentage (which was set at 10%) was too low. The part had too much void space and there was not enough supporting material as the printer made its final pass. I looked through the holes to look inside and it is mostly hollow.
I would not consider this 3D printing session a failure though. I love hands on learning and it was great to see the printer work its magic! I’m now more comfortable with the process to setup the printer as well. I am very tempted to conduct another 3D printing session and increase the infill percentage to see if this solves the problem.