3D Printing: Prototyping and End-Use Parts
With FDM(Fused Deposition Modeling) printers becoming more readily available, the ability to create parts, for both modeling and prototyping, has never been more effortless. With a press of a button, anyone can produce complex shapes and bring their CAD designs to life. Thanks to FDM technology, 3D printing has been our primary source of custom parts since the beginning of AmadorUAVs due to our access to numerous 3D printers and its overall flexibility. Although this emerging technology has helped our team at AmadorUAVs throughout the development of our drones, the level of detail required for the printing of end-use parts has proven to be difficult for the team.
Slicing Software: Cura
Cura is an open-source slicing software designed by Ultimaker to provide an easy, user-friendly solution to 3D printing. It’s catered towards both professionals and hobbyists and provides AmadorUAVs with a simple and easy solution to work with. For the most part, Cura has served its purpose and allowed us to work with both our Ultimaker 3 and Ender 3, but its user-friendly UI has proven to be challenging to work with.
The first major hurdle in our experiences with Cura has been the various non-printable areas that limit print size for no apparent reason. While most of the limits are due to print settings and can often be minimized, but the advertised 215 x 215 mm print area has never been achieved. Most of the parameters that limit print area are often crucial for the print: Dual extrusion, Build plate adhesion, and numerous pre-print procedures. While the non-printable areas are there to ensure a good quality print, it has often proven to be problematic with our bigger, more straightforward prints.
End-Use Parts: Print Quality
When it comes down to prototyping and printing end-use parts, the model in mind has to feature near-perfect print quality with little to no errors. The most common material for this use case is nylon.
Nylon is one of the strongest conventional material available for FDM printing. It offers high tensile strengths and resistance to everyday wear including temperature and chemicals. Although nylon provides the best results, printing with it is difficult. Its ability to absorb water and its high melting temperature are just a few of the problems when printing with nylon. Its nature makes it difficult to print without stringing and releases toxic fumes into the air. And in our case, nylon has mostly been disregarded as the flexibility of the material had made it difficult for our thin drone parts.
PLA
By choosing to use PLA instead of Nylon,
Speed vs. Quality
The two major components in 3D printing are speed and quality. Both are equally important and trying to increase one can have devastating effects on the other. The team learned this the hard way after our Ultimaker suffered from a crash and refused to recover. Due to our tight schedule, we were forced to finish printing all of the components for our drone that day. In order to meet the deadline, our team had to rush the printing, running both the Ultimaker 3 and Ender 3 near its limit with a 0.3mm layer and 70mm/s print speed. with a .4mm nozzle, printing at these speeds lead to high pressures on the nozzle and often breaks cheap nozzles. But by taking this risk, we were able to bring down a 4-hour print down to 2-hour print, allowing for us to meet the deadline and get our drone assembled on time.
While the print on the Ultimaker was successful, the Ender 3’s print was a different story. The result seemed functional, but when tested, it was significantly lighter than the others and broke apart easily when stressed. This was due to the under-extrusion of the material, which caused the layers to bond poorly, resulting in a brittle, weak part. The under-extrusion was caused by the Ender 3 inability to melt and push the plastic through the small .4mm nozzle which was crucial in lowering print time. Although the printer was unable to print a good quality part, the fault was on our team for disregarding the specifications and public knowledge of the $200 printer and pushing it past its limits while assuming that it would function similarly to a $3000 printer.
