Discipline: Technology and Engineering
Subcategory: Civil/Mechanical/Manufacturing Engineering
Cyron Ferguson - FAMU-FSU College of Engineering
Co-Author(s): Dr. Carl Moore, FAMU-FSU College of Engineering ; Dr. Tarik Dickens, FAMU-FSU College of Engineering ; Dr. Hui Wang, FAMU-FSU College of Engineering
Additive manufacturing is the application of joining materials layer upon layer to make 3D models and functional prototypes. 3D printers are a subset of additive manufacturing, and the Dexter 2.0 is a SCARA ARM 3D printer built under a grant from the NSF-RISE program. The goal of the Dexter 2.0 is to be a flexible agent in a cyber-physical system. My research task was to improve the printing resolution of Dexter 2.0 which was low compared to marketed 3D printers. My hypothesis was that I could improve print resolution by switching to a higher resolution stepper motor and larger drive transmission ratio under the following requirements: meet required acceleration/torque characteristics, connect well with redesigned robot arm joint, and maintain acceptable overall weight.
To complete my research, I studied available stepper motors and used MATLAB to model the inverse kinematics of the Dexter 2.0 arm including stepper resolution and drive transmission ratio. With the program, I calculated the transmission ratio required for a given stepper resolution to achieve an overall system resolution and speed similar to that of popular desktop 3D printers. I plotted the variables on a multi-axis graph to find where the highest resolution could be achieved given the speed and cost requirements. Once I found a possible candidate stepper motor and transmission combination, I used CAD software to perform weight analysis of the design changes effect on the robot?s arms. The weight analysis showed that the arms could withstand the new actuators and transmission design. The new steppers and transmission were implemented on the Dexter 2.0, and they met all the initial requirements.
The Dexter 2.0 is a great system that could potentially revolutionize the additive manufacturing industry. Open research questions include: (1) how can the resolution of the arm joints be further increased without unsustainable speed reductions and (2) can the Dexter 2.0 be designed to cost less and perform better than similar Cartesian 3D printers currently on the market.
References: J. B. Frketic, S. Psulkowski, A. Sharp, and T. Dickens, ‘Dexterous Printing and Fabrication of Multi-Functional Parts: Design for Science and Engineering Education,’ Procedia Manufacturing, vol. 10, pp. 1087-1096, 2017.
Funder Acknowledgement(s): Funder Acknowledgements: This work is supported by The National Science Foundation under grant No. 1560337 and RISE #1646897. Additional thanks to leadership of Centers HPMI and AME for the use of the facility. The design and manufacturing application is under FAMU disclosure. Final thanks to Mr. Sean Psulkowski, Twan Capehart and Dr. Chiang Shih for added support on the project.
Faculty Advisor: Carl A. Moore Jr., carl.moore@famu.edu
Role: Designed new transmission components and added them to the CAD drawings Wrote MATLAB programs to analyze robot kinematics Performed weight analysis Tested final design in MATLAB simulation