…This project is based on the open-source, low-cost metal 3D printer developed by Joshua Pearce at Michigan Technological University where a low-cost commercial gas-metal arc welder and a derivative of the Rostock, a deltabot RepRap were used to lay down thin layers of steel to form complex geometric objects.
The team at TU Delft instead used a Cartesian system – a Prusa i3 – for their metal printing application. They explained:
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.
Using this setup they were able to make the first few prints: a few very straight lines and then a vertical wall. The MIG (Metal Inert Gas) welder was set to feed wire at a rate of 4 m/min and the travel rate of the torch was 300mm/minute, which is relatively slower than the consumer FDM 3D printer….