Today we’re going to tell you about our decision for our 3D printer system. The printer built by the Michigan University used a delta system, quite a well-known system for polymer 3D printers. We however, argue that a Cartesian system would be much better suited for our metal printing application. The reason for this is that the main advantages of a delta system, less materials required and a lower weight, implicate a major disadvantage for any MIG welder based metal 3D printer.
First of all, the delta system used by Michigan University was an upside down version of the commonly found system on polymer printers. This means that the very heavy printing bed was being moved on all axes while the relatively lighter torch remained in a fixed position. The high weight of the bed combined with the relative weakness in the arms, motors and drive of the delta system could easily allow for excessive movement of the bed due to the momentum gained by this heavy object. This means that it would prove very hard to make significant improvements to the quality of the printed object.
Therefore, we decided to swap the delta system for a Cartesian system, much like the well-known Ultimaker printers. This systems allows us move the bed only on the Y axis, while moving the torch over the X- and Z axis, thus improving control over the project because we limit the impact of the momentum gained by the bed and project. An additional inherent advantage of the Cartesian system is a significant improvement in ease of use. Whereas the delta system requires a mathematical model to control the axis, making calibration a tricky and time consuming process, the Cartesian model allows for easy control by simply putting in coordinates, as well as straight forward calibration. These factors make us believe that the Cartesian system is a lot more promising and accessible, both in quality of the print as in ease of use, thus enhancing the likeliness that other people will take on this project and further improve it when we are finished.
More detailed schematics of our soon-to-be printer will follow!