Development of an error compensation case study for 3D printers

The paper developed presents a case study that allows students to learn an easy way to improve the accuracy of low cost 3D printers. The document detailed a methodology to achieve this goal. First, it is necessary to print an initial CAD design. A commercial scanner is calibrated and the pieces are scanned to obtain the different errors. Then, a program is generated to compensate the code numerical control of the printer. This fact allows students to print a new piece having less errors than before, which it involves improve the printer accuracy

Education Software for the Modelling and Calibration of Kinematic Mechanisms

AbstractThis paper presents a new software for teaching the most important aspects of modelling, characterization and calibration of parallel mechanisms by means of the kinematic model, the kinematic parameter identification and the control of the system actuators and sensors. This application allows the student to develop competencies such as analysis and synthesis, to solve problems, research skills and to apply their knowledge.The developed tool presents a special interest in areas such as education, industry and research, since the application interface allows the user to carry out the different steps of the calibration procedure in an easy way. Besides, only one application is necessary to perform all the procedure for data acquisition and kinematic parameter identification.Moreover, thanks to the flexibility that the developed software offers in the programming, a senior undergraduate student can modify different algorithm variables and analyze the effects that take place with these changes. This application therefore presents an important utility as a teaching tool for the learning process and analysis of the different steps in the parallel mechanism optimization

Modelling, kinematic parameter identification and sensitivity analysis of a Laser Tracker having the beam source in the rotating head

This paper presents a new kinematic model, a parameter identification procedure and a sensitivity analysis of a laser tracker having the beam source in the rotating head. This model obtains the kinematic parameters by the coordinate transformation between successive reference systems following the Denavit–Hartenberg method. One of the disadvantages of laser tracker systems is that the end-user cannot know when the laser tracker is working in a suitable way or when it needs an error correction. The ASME B89.4.19 Standard provides some ranging tests to evaluate the laser tracker performance but these tests take a lot of time and require specialized equipment. Another problem is that the end-user cannot apply the manufacturer’s model because he cannot measure physical errors. In this paper, first the laser tracker kinematic model has been developed and validated with a generator of synthetic measurements using different meshes with synthetic reflector coordinates and known error parameters. Second, the laser tracker has been calibrated with experimental data using the measurements obtained by a coordinate measuring machine as nominal values for different strategies, increasing considerably the laser tracker accuracy. Finally, a sensitivity analysis of the length measurement system tests is presented to recommend the more suitable positions to perform the calibration procedure

Identification and Kinematic Calculation of Laser Tracker Errors

AbstractCalibration of Laser Tracker systems is based most times in the determination of its geometrical errors. Some standards as the ASME B89.4.19 (2006) and the VDI 2617-10 (2011) describe different tests to calculate the geometric misalignments that cause systematic errors in Laser Tracker measurements. These errors are caused not only because of geometrical misalignments and other sources of error must also be taken in count. In this work we want to express the errors in a kinematic form. Errors will be split in two different components, geometric and kinematic errors. The first ones depend on the offsets, tilts and eccentricity of the mechanical and optical components of the system. Kinematic errors are different for every position of the Laser tracker, so they must be formulated as functions of three system variables: range (R), vertical angle (V) and horizontal angle (H). The goal of this work is to set up an evaluation procedure to determine geometric and kinematic errors of Laser Trackers

Implementing Sustainability Criteria in Product Development

AbstractThis work analyses the product development process of two different mechanical assemblies in order to put into practice redesign strategies that allow obtaining more sustainable products.The study of the manufacturing process has been focused on obtaining material and energy consumptions. Sustainable design criteria have been applied preserving the initial specifications of each product. A number of approaches as the material replacement, the reduction of the final product mass and an effective utilization of raw materials have been proposed. A reduction of the environmental impact, which was assessed trough global energy and global warming eco-indicators, has been achieved