Challanges In Constructing Large Frame FDM 3D Printers

Sammanfattning: This project was initiated by Postnord who wanted to develop their own large frame FDM 3D printer, mainly for two reasons. The first reason was to be able to use the collaboration between Postnord and KTH to present how Postnord are promoting domestic production in the same time as portraying themselves as leaders in the field of additive manufacturing in Sweden. The second reason was to get a machine with the ability to print both small- and large-scale prototypes and products to be used in an industrial environment. The targeted goals and desired outcome of the PP3D (PostPaper3D - project name) was to construct a large frame FDM 3D printer, with a build area of 1 square meter and (if possible) a printing volume of 1 cubic meter, capable of printing parts for industrial applications. This would be achieved by using industrial components and state-of-the-art open source 3D printing control systems. Sensors for filament run-out detection and automatic printer bed levelling was also desired. On top of these goals KTH-IIP wanted the project work to focus on the construction of large frame FDM 3D printers, what challenges appear in scaling up the technology, to further the internal vision of developing strategic competencies in the field of additive manufacturing - as requested by the industry. The result of the project was a FDM 3D printer with a build volume of 1000x1000x950 [mm] that comes with dual independent extruders - meaning it may either print two copies of the same part simultaneously or utilize both printer heads to work on a single component. The top tested speed (printing) was 100 [mm/s] and the top tested movement speed was 250 [mm/s]. The theoretical accuracy of the machine is 50 [μm] but this has not been tested in this project. In the scope of the master thesis all prototype-symptoms were not eliminated, where the most considerable issue being the motors occasionally skipping steps (and losing their location) during rapid accelerations and changes in velocity. When this happens, it will most likely result in a failed print. The proposed solution for this is to further adjust the firmware to allow for finer, more regulated accelerations and speeds. Another possible solution is to replace the motors with stronger ones. In delivery the machine operates using state of the art components and software, from prominent Swedish and international producers. An interview of Isak Emericks alongside the printer can be seen in Appendix B, in the form of a newsletter.