Hello, we are a team of four engineering students at WPI (Worcester Polytechnic Institute) that are currently taking the Introduction to Engineering Design course remotely. A project we are working on is to design a face shield. Our goals for the design were security, adjustability and comfortability to the user.
One of our priorities was to make sure the gap between the user’s head and the guard was filled in, in order to eliminate the risk of bacteria flowing in from the top. In addition, we decided to have a wide front surface, so that the user is more comfortable rather than with a thin plastic rubbing on their head. In addition, the holes on its side allow for increased flexibility and less material to be consumed during manufacturing. Lastly, similarly to other designs, the bended arms allow for the apparatus to be used only with the use of an elastic band or strap. Furthermore, the multiple hooks (3) provide the ability to adjust in different head circumference.
We printed our design in PLA using a Monoprice Maker Select Plus (also known as a Wanhao Duplicator i3 Plus) and sliced it using Ultimaker Cura. This printer has a 200 mm x 200 mm build platform, which was not large enough to print two of the original designs given for the quiz, or our final design. In order to still get proper numbers on print time and material use, a new printer setting with a much larger build plate and similar settings to the Monoprice was created in Cura. This was only done in order to get the print time and material requirement for a full scale print.
We printed our design at 90% scale in order to fit on the build plate. The print was 10% infill and did not use a raft, however a skirt was printed around the part to get the filament flowing through the extruder. Supports were created in the six side holes to ensure the structural integrity of the print. The print head traveled at 100 mm/s, while the nozzle was at 210 degrees celsius, and the bed was at 60 degrees celsius. Heating the bed was not 100% necessary but through previous testing with the printer, it aids with first layer adhesion.
Print time on Monoprice Maker Select at 90% scale: 2hr 23 min at 21g
Print time on Sindoh 3DWOX DP200 3D Printer at 90% scale: 1hr 8min at 21.1g
*we found that 90% scale is still suitable for average head dimensions.
WHO :
Mary Decelles
Marc Wicky van Doyer
Eric Stultz
Angelos Makras
