Encapsulation of electronic hardware into FDM manufactured thermoplastic drone structures

• Main Author: Keane, Phillip
• Other Authors: Chua Chee Kai
• Format: Theses and Dissertations
• Language: English
• Published: 2017
• Subjects: DRNTU::Engineering::Aeronautical engineering; DRNTU::Engineering::Manufacturing::Polymers and plastics
• Online Access: http://hdl.handle.net/10356/72880
• Institution: Nanyang Technological University

FDM (Fused Deposition Modeling) additive manufacturing is allowing manufacturers to consolidate multiple complex assemblies into single printed parts, with minimal reduction in geometric complexity. This has the potential to reduce both manufacturing and assembly steps. This reduction in production stages can result in cost savings, reduction in assembly line components and also in fewer technical staff required for manufacturing operations. This thesis will build upon these ideas by adding electronic components into the 3D printing stage and will use a 3D printed quadcopter as an example. The aim is to demonstrate a proof-of-concept of functional electronic systems within a high temperature printing process, and to determine best practices for the embedding of hardware. In order to reduce the number of fasteners in the printed drone, snap-fit clips were printed in-situ as part of the drone airframe. This thesis will examine some of the limitations involved when printing snap-fit clips of small scale, and provides a graph showing a zone of manufacturability, based on printer extrusion width dimensions for a given strain requirement. It is demonstrated that a clip must be a minimum of 0.8128 mm thick in order to be manufactured by 3D printing in accordance with the literature guidelines for snap-fit clips. Additionally, it is shown that when a print job is paused, cooled and restarted in order to embed separate hardware items, the bond layer at the pause is weakened. This weakening effect results from the thermal history and this thesis will investigate and quantify the effects of cooling on the bond strength. In summary, the loss of bond strength cannot be recovered by reheating the part, and the loss of strength can be minimised by a combination of the highest print chamber setting (170℃), a minimal reheat time (2 minutes 5 seconds) and a cooling temperature of 80℃.