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KASSANDRA – CHALKIDIKI, GREECE OCTOBER, 2008. MINI EDUCATIONAL 3-AXIS PARALLEL KINEMATIC MILLING MACHINE. Dragan Milutinovic 1 , Milos Glavonjic 1 , Sasa Zivanovic 1 , Zoran Dimic 2 , Vladimir Kvrgic 2 1 Mechanical Engineering Faculty, University of Belgrade 2 LOLA Institute, Belgrade
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KASSANDRA – CHALKIDIKI, GREECEOCTOBER, 2008. MINI EDUCATIONAL 3-AXIS PARALLEL KINEMATIC MILLING MACHINE Dragan Milutinovic1, Milos Glavonjic1, Sasa Zivanovic1, Zoran Dimic2, Vladimir Kvrgic2 1 Mechanical Engineering Faculty, University of Belgrade 2 LOLA Institute, Belgrade Serbia
3rd ICMEN, OCTOBER 2008, KASSANDRA – CHALKIDIKI, GREECE CONTENTS • INTRODUCTION • MECHANISM STRUCTURE AND CHARACTERISTICS • MECHANISM MODELLING • SINGULARITY ANALISYS • EXPERIENCES IN THE FIRST MILLING MACHINE PROTOTYPE DEVELOPMENT • DEVELOPMENT OF MINI EDUCATIONAL MILLING MACHINE • EDUCATIONAL MILLING MACHINE PROTOTYPE • CONCLUSIONS
3rd ICMEN, OCTOBER 2008, KASSANDRA – CHALKIDIKI, GREECE INTRODUCTION The developed mini educational 3-axis parallel kinematic milling machine is based on a newly developed 3-DOF spatial parallel mechanism. This mechanism was first used for successful development of experimental vertical milling machine prototype described in detail in. On the basis of several-years’ experience in developing vertical milling machine prototype, we arrived at the conclusion that based on the same mechanism a low-cost mini educational 3-axis parallel kinematic milling machine can be developed as a help in the process of acquiring basic experiences in the field of PKM. The paper describes the structure of mechanism, modelling approach, developed experimental prototype of mini educational 3-axis parallel kinematic milling machine, and control and programming system based on PC Linux platform.
MECHANISM STRUCTURE AND CHARACTERISTICS 3rd ICMEN, OCTOBER 2008, KASSANDRA – CHALKIDIKI, GREECE Mechanism’s model
Decoupling of platform’s motion in Z and Y direction, exceptional WS regularity with Zmin=const. and Zmax=const. on its boundaries for each of Ymin≤Y≤Ymax, 3rd ICMEN, OCTOBER 2008, KASSANDRA – CHALKIDIKI, GREECE - Passive translatory DOF or joint in Y direction: - Parallel guideways: • Arbitrary WS length in X direction, • Regular WS shape on its boundaries in Y direction, Ymin=const. and Ymax=const.
3rd ICMEN, OCTOBER 2008, KASSANDRA – CHALKIDIKI, GREECE - Crossed joint parallelograms c1 and c2: • Decreasing of the guideways length for the same X dimension of WS, • Smaller curvature at Xmin and Xmax borders of WS.
3rd ICMEN, OCTOBER 2008, KASSANDRA – CHALKIDIKI, GREECE Milling machine prototype • Actuators • Control system • Programming • Max feedrate 10m/s
MECHANISM MODELLING 3rd ICMEN, OCTOBER 2008, KASSANDRA – CHALKIDIKI, GREECE Inverse kinematics equations Direct kinematics equations Geometric model of the mechanism
SINGULARITY ANALYSES Significant singularity types
DEVELOPMENT OF MINI EDUCATIONAL MILLING MACHINE 3rd ICMEN, OCTOBER 2008, KASSANDRA – CHALKIDIKI, GREECE • The first step was to set the goals that can be summed up as follows: • It is a low-cost mini desktop machine, • it can machine soft materials, • it is programmable in a common way, • it is fully safe for user-beginners. • Using the thus determined goals, elaboration of the concept involved: • dimensional analysis of the machine and workspace, • conception of basic units with the choice of possible solutions
DEVELOPMENT OF MINI EDUCATIONAL MILLING MACHINE 3rd ICMEN, OCTOBER 2008, KASSANDRA – CHALKIDIKI, GREECE Prototype CAD mode Workspace of developed prototype
3rd ICMEN, OCTOBER 2008, KASSANDRA – CHALKIDIKI, GREECE CONCLUSIONS In order to contribute to acquiring experience in modelling, design, control, programming and use of PKM, a low-cost educational 3-axis parallel kinematic milling machine is proposed. The developed mini educational parallel kinematic milling machine is based on newly developed 3-DOF spatial parallel mechanism with specific advantages in comparison with similar mechanisms. The developed low-cost mini educational parallel kinematic milling machine could be comprehensive and sophisticated didactic facility. The laboratories, universities and schools may find a planned commercial version of this machine.