| Abstrakt: |
The accuracy of the products of 3D printers is a very important parameter. Many parameters that affect this accuracy, such as staircase effects, support effects, radius effects, offset and curved boundary effects, slicing and swelling effects, properties and dynamic behavior of machine drives. This study looks for the relationship between the radius effect and dynamic characteristics of 3D printer machines with Selective Laser Melting technology on the accuracy of corner formation. As the research material, PLA powder was spread and leveled on a glass substrate to form a single layer of PLA powder with a thickness of 0.9 mm. In the process of forming objects that have an angle of 90°, theoretically, the tip will have a curvature radius equal to the radius of the laser beam. However, due to the occurrence of a melt that is wider than the laser beam, the fillet radius that occurs will be greater. In right-angle formation, 2 motion mechanisms are needed, the first motion mechanism towards the x-axis then stops in one position and the second motion mechanism towards the y-axis. This is the process of acceleration and deceleration of the two mechanisms. As a result of the start and stop process, this will also affect the shape of the formed fillet. To find out the shape that occurs when the laser position stops, four specimens are made by giving a laser power of 8, 12, 16 and 20 Watt respectively with a very short time. From the measurement of the results of melt in the form of dots, it turns out that the point diameter that occurs is an average of 2.05 mm and is not affected by the amount of laser power. Furthermore, specimens were made in the form of four 50 mm lines with a speed of 16 mm/s and laser power of 8, 12, 16 and 16 Watt respectively. The tip curvature radius at start and stop is almost the same as 1.1 mm. The size of the curvature radius at start process and stop process turns out to be the same as the point radius that occurs in the point formation experiment, so the curvature radius when forming the right angle is predicted to be 1.1 mm and not affected by the magnitude of the laser power. This is evident from the formation of a 90° angle specimen, i.e. the fillet radius that occurs is 1.1 mm. [ABSTRACT FROM AUTHOR] |
