Michigan Technological University Digital Commons @ Michigan Tech Dissertations, Master's Theses and Master's Reports 2021 Design and Testing of an Open Source Vacuum Oven for Research, Community Recycling, and Additive Manufacturing Benjamin R. Hubbard Michigan Technological University, [email protected] Copyright 2021 Benjamin R. Hubbard Recommended Citation Hubbard, Benjamin R., "Design and Testing of an Open Source Vacuum Oven for Research, Community Recycling, and Additive Manufacturing", Open Access Master's Thesis, Michigan Technological University, 2021. https://doi.org/10.37099/mtu.dc.etdr/1215 Follow this and additional works at: https://digitalcommons.mtu.edu/etdr Part of the Manufacturing Commons DESIGN AND TESTING OF AN OPEN SOURCE VACUUM OVEN FOR RESEARCH, COMMUNITY RECYCLING, AND ADDITIVE MANUFACTURING By Benjamin Robert Hubbard A THESIS Submitted in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE In Mechanical Engineering MICHIGAN TECHNOLOGICAL UNIVERSITY 2021 © 2021 Benjamin Robert Hubbard This thesis has been approved in partial fulfillment of the requirements for the Degree of MASTER OF SCIENCE in Mechanical Engineering. Department of Mechanical Engineering-Engineering Mechanics Thesis Co-Advisor: Joshua M. Pearce Thesis Co-Advisor: Gordon G. Parker Committee Member: Rebecca G. Ong Department Chair: William W. Predebon To my family, my love, and 2Q2. Table of Contents List of Figures .................................................................................................................... vi List of Tables .......................................................................................................................x Author Contribution Statement .......................................................................................... xi Acknowledgements ........................................................................................................... xii List of Abbreviations ....................................................................................................... xiii Abstract ............................................................................................................................ xiv 1 Introduction .................................................................................................................1 1.1 References ........................................................................................................3 2 Open Source Digitally Replicable Lab-Grade Scales .................................................6 2.1 Introduction ......................................................................................................6 2.2 Materials and Methods .....................................................................................7 2.2.1 Design .................................................................................................7 2.2.2 Bill of Materials ..................................................................................8 2.2.3 Manufacturing and Assembly ...........................................................12 2.2.4 Firmware ...........................................................................................18 2.2.5 Operation of Design ..........................................................................20 2.2.5.1 Simple Scale....................................................................20 2.2.5.2 Lab Scale with Serial Interface .......................................20 2.2.6 Validation ..........................................................................................21 2.2.6.1 Laboratory-Grade Scale Comparison .............................21 2.2.6.2 Self-Calibration of Open Source Scale for 100 g TAL221 22 2.2.6.3 Measurement on Open Source Scale Using Standard Masses 22 2.2.7 Economic Analysis ...........................................................................23 2.3 Results ............................................................................................................23 2.3.1 Laboratory-Grade Scale Comparison ...............................................24 2.3.2 Standard Mass Measurements...........................................................27 2.3.3 Economic Analysis ...........................................................................28 2.4 Discussion ......................................................................................................29 2.4.1 Open Source Scale for Distributed Manufacturing ...........................29 2.4.2 Future Technical Work .....................................................................30 2.5 Conclusions ....................................................................................................31 2.6 References ......................................................................................................32 3 Open Source Vacuum Oven for Low-Temperature Drying .....................................39 3.1 Introduction ....................................................................................................39 iv 3.2 Materials and Methods ...................................................................................40 3.2.1 Design ...............................................................................................40 3.2.1.1 Vacuum System ..............................................................40 3.2.1.2 Thermal Controls ............................................................41 3.2.2 Bill of Materials ................................................................................42 3.2.3 Manufacturing and Assembly ...........................................................46 3.2.3.1 Vacuum Chamber ...........................................................46 3.2.3.2 Thermal Control System .................................................50 3.2.3.3 Finishing the Assembly...................................................54 3.2.4 Code ..................................................................................................55 3.2.5 Operation...........................................................................................56 3.2.6 Materials for Testing .........................................................................56 3.2.6.1 Plastics ............................................................................56 3.2.6.2 Biomaterials ....................................................................57 3.2.7 Testing...............................................................................................58 3.2.7.1 Thermistor Calibration ....................................................58 3.2.7.2 Temperature Gradient Measurements .............................58 3.2.7.3 Drying Rate Comparison ................................................59 3.2.7.4 Filament Drying ..............................................................60 3.2.8 Economic Analysis ...........................................................................60 3.3 Results ............................................................................................................61 3.3.1 Thermistor Calibration ......................................................................61 3.3.2 Temperature Gradient Testing ..........................................................62 3.3.3 Drying Tests ......................................................................................64 3.3.4 Filament Drying ................................................................................68 3.3.5 Economic Analysis ...........................................................................69 3.4 Discussion ......................................................................................................69 3.5 Conclusions ....................................................................................................72 3.6 Appendix A – Vacuum Selection ...................................................................72 3.7 Appendix B – Wiring Instructions .................................................................72 3.8 References ......................................................................................................73 4 Future Work ..............................................................................................................80 A Copyright documentation..........................................................................................81 v List of Figures Figure 2.1. Electrical circuit breadboard layout. Please note that all components connected to and including the LCD are optional. ................................................13 Figure 2.2. Electrical circuit wiring diagram. Pinouts on the Arduino were selected to reduce the number of required jumper wires when using an Arduino Nano. Pinout selection can be modified in the firmware header file, Pinouts.hpp. Changing micro-controllers or pinouts may require different circuit parts than those listed in Table 2.1. ...............................................................................................................14 Figure 2.3. The circuit was assembled on a solder circuit board using jumper wires and header pins. The female header pins connect to the Arduino Nano and the HX711. The male header pins connect to the load cell and the LCD. The tare push-button is attached via twisted pair to allow installation on the face of the scale. (a) The soldered components were arranged in such a way to minimize wire use and to properly place the Arduino when installed in the base. (b) Shows the final circuit