# Suitability of UR5 Robot for Robotic 3D Printing
## 1 Introduction  
Robotics represents an interdisciplinary branch concerned with robot design, development, construction, and use. These devices can perform various tasks traditionally performed by humans, yet often at a faster, more accurate, and efficient rate. The application of robots in manufacturing offers numerous benefits. Robots can work continuously with no interruption, resulting in increased manufacturing productivity. Additionally, they excel at repetitive tasks with high accuracy, reducing the risk of errors and improving product quality. Another advantage is their safety when handling complex processes. The latest robots are equipped with advanced sensors and machine learning algorithms, allowing them to adapt to different applications. Their integration into the industry is widespread, and they are utilized in many industrial areas for various purposes [1]. Robots combined with advanced AI algorithms, machine vision, sensing, and IoT elements are becoming automated manufacturing equipment [2, 3].  
Additive manufacturing is the process of creating objects by adding material layer by layer. Incorporating robots into this process is quite challenging, as it demands high accuracy in executing the motions of the print head mounted on the robot arm during robotic 3D printing [4]. The robots' high positioning accuracy increases their potential in this highlyadvancing manufacturing technology. Their size is also a considerable advantage compared to commonly available 3D printers, with the robot allowing the printing of proportionally larger components [5; 6], even in multiple directions of motion in a non-planar manner, as is the case with commercially available 3D-printing devices [7]. Furthermore, the robot also allows performing other programmed tasks involved in finishing the print, such as cleaning, polishing, or assembling components by the assembly, after the 3D printing process is completed. This is possible due to its flexibility and the ability to quickly change tools in an automated manner during production [8].  
Inaccuracy in robotic 3D printing appears to be a complex issue potentially caused by a combination of factors, including object dimensions, material choice, printing temperature, layer height of the material applied, print head motion strategy, and print cycle length. Incorrect setting of the input parameters may cause excessive heating of the print head or substrate and consequent deformation of the printed object with loss of mechanical properties of the print, thus affecting its final dimensions and accuracy. A further factor is the accuracy of the mechanical parts of the drive of the device and the effect of drift and static compliance of the robot in robotic 3D printing. In the present paper, the focus is mainly on the drift and static compliance of the Universal UR5 robot chosen for the application in robotic 3D printing, since the commonly available commercial devices designed for 3D printing of objects have a declared printing accuracy of \(\pm\)0.1 mm. Therefore, it was necessary to verify the selected robot to achieve the required positioning capability (manufacturer's stated accuracy of 0.1 mm) for its suitability for application in robotic 3D printing. These factors directly affect the robot's capability to accurately manipulate the print head in the manufacturing process.