7
Contents
Abstract………..1 Sommario………...2 Nomenclature……….3 Contents……….5 1. Introduction………..72. State of the art of micro-milling technologies……….9
2.1 Micro-machining technologies……….9
2.1.1 Difference between micro-cutting and other methods………..10
2.1.2 Micro-machine and micro-factories………..10
2.2 Micro-milling………..11
2.2.1 Introduction………..…….11
2.2.2 Rounded-Edge Cutting Model (RECM)………12
2.2.3 Chip formation and minimum chip thickness………...12
2.2.4 Cutting force………..13
2.2.5 Effect of work-piece material………13
2.2.6 Dynamics effects………...14
2.3 Requirements of micro-milling on machine tools………..14
2.4 Current method to evaluate machine tools………..17
2.4.1 Evaluation of the stiffness of the machine’s components………..…...17
2.4.2 Dynamic effects……….18
2.4.3 Positional accuracy………20
2.4.4 Thermal aspects……….21
2.5 Conclusions……….23
3. Problem description and goal of the assignment………...24
3.1 Micro-milling at TU Delft………..24
3.2 Goal of the assignment………28
3.3 Error budget in micro-milling……….30
3.4 Performances to be evaluated……….31
4. Introduction of the instruments………..33
4.1 Introduction……….33
4.2 Keyence Microscope………...33
4.3 Keyence Laser Sensor……….34
4.4 Automation 3200………35
5. Stiffness chain evaluation of the setup………...36
5.1 Introduction……….36
5.2 Tool stiffness………...38
5.2.1 Design of method………..38
5.2.1.1Theoretical analysis………..40
5.2.1.1.1 One cylindrical section cantilever beam model………..……..40
5.2.1.1.2 Three sections beam model………...42
5.2.1.2FEM analysis………....43 5.2.1.3Experimental setup………...47 5.2.2 Experimental results…..………49 5.2.2.1Ø0,3mm tool………49 5.2.2.2Ø0,5mm tool………50 5.2.2.3Ø1,9mm tool………50
5.2.3 Conclusions and analysis of the results...………50
5.3 Bridge and Z stage………..55
8
5.3.2 Design of method………..55
5.3.2.1Theoretical analysis…..………56
5.3.2.1.1 Cutting force in X-direction……….……….59
5.3.2.1.2 Cutting force in Y-direction………..61
5.3.2.2FEM analysis………..………..62
5.3.3 Experimental setup………63
5.3.4 Experimental results………..65
5.3.5 Conclusions and analysis of the results...………..65
5.4 Spindle and Tool-holder……….67
5.4.1 Introduction………...67
5.4.2 Design of method………..67
5.4.2.1Theoretical analysis……….68
5.4.2.1.1 “Spindle+Tool-holder compliance” model………...…68
5.4.2.1.2 “Tool-holder compliance” model……….70
5.4.2.2FEM analysis…..………..72
5.4.3 Experimental setup………73
5.4.4 Experimental results………..75
5.4.5 Conclusions and analysis of the results……….75
5.5 X and Y stages………80 5.5.1 Introduction……….80 5.5.2 Design of method………80 5.5.3 Experimental setup………..81 5.5.4 Experimental results………81 5.5.4.1X-direction………..……81 5.5.4.2Y-direction………..82
5.5.5 Conclusions and analysis of results………83
5.6 Conclusions on the stiffness chain………..84
6. Dynamic accuracy………..87
6.1 Introduction……….87
6.2 Design of method………90
6.3 Experimental setup………..92
6.4 Experimental results………92
6.5 Analysis and discussion………..99
7. Geometric accuracy……….101
7.1 Introduction………...101
7.2 Design of method………..104
7.3 Experimental setup………105
7.4 Experimental results………..106
7.5 Analysis and discussion………113
8. Conclusions and recommendations………..117
8.1 Conclusions………...117
8.2 Error budget of the micro-milling setup………...117
8.3 Recommendations for future work………...118
References………..119 Appendix A………122 Appendix B……….132 Appendix C……….137 Appendix D………141 Appendix E……….143 Appendix F……….147 Acknowledgement………..155
