WORCESTER POLYTECHNIC INSTITUTE 3-in-1 Saw Major Qualifying Project AY 2012, 2013 Edward Galvin Mathew Fredrick Timothy Moreau Design and prototyping of a carpenter’s saw to perform the functions of three different saws; slide-compound miter saw, table saw, and handheld circular saw. Table of Contents Background Information ................................................................................................................. 5 Glossary of Terms ........................................................................................................................... 5 Types of Saws ................................................................................................................................. 6 Circular Saw ............................................................................................................................ 6 Chop Saw ................................................................................................................................. 7 Table Saw ................................................................................................................................ 7 Background Research ..................................................................................................................... 8 Overview ......................................................................................................................................... 8 Flip-Over Saws ............................................................................................................................... 8 Category II Saws ............................................................................................................................. 9 Conclusions ................................................................................................................................... 10 Design Process .............................................................................................................................. 10 General Schematic Design ............................................................................................................ 11 Introduction ........................................................................................................................... 12 Circular Saw Attachment Design Progression ...................................................................... 12 Aligning the Circular Saw ..................................................................................................... 12 Locking Devices .................................................................................................................... 13 Converting the Miter Saw to a Table Saw .................................................................................... 14 General Conversion Concept ................................................................................................. 15 Locking Mechanisms ............................................................................................................. 15 Controlling Table Motion ...................................................................................................... 16 Raising and Lowering the Table Saw Blade ......................................................................... 16 Design Details ............................................................................................................................... 17 Circular Saw Details .............................................................................................................. 17 Miter Saw Details .................................................................................................................. 17 Table Saw Details .................................................................................................................. 23 Design of Blade Raising and Lowering Device .................................................................... 25 Prototyping .................................................................................................................................... 26 Evaluation ..................................................................................................................................... 29 Recommendations ......................................................................................................................... 29 3-in-1 Combination Saw MQP Page 1 Safety Features .............................................................................................................................. 29 Design Built-In Table Safety Specifications................................................................................. 31 Optimize for Weight and Material Selection ................................................................................ 31 Design for Manufacturability and Tolerances .............................................................................. 32 Works Cited .................................................................................................................................. 33 Appendix A: MathCad Calculations ............................................................................................. 35 Appendix B: Weekly Meeting Notes ............................................................................................ 37 Appendix C: Poster Presentation .................................................................................................. 45 3-in-1 Combination Saw MQP Page 2 Table of Figures Figure 1: Circular Saw (Circular Saw) ........................................................................................... 6 Figure 2: Miter Saw (Dewalt Miter Saw) ....................................................................................... 7 Figure 3: Table Saw (Craftsman) .................................................................................................... 7 Figure 4: DeWalt DW743 Flip-Over Saw – Left (DW743N-QS) .................................................. 8 Figure 5: Bosch GTM 12 Professional Category II Saw – Right (Bosch Table Saw).................... 8 Figure 6: Patent US 20100269660 A1 Category II Saw – Left (Patent US20100269660) ............ 9 Figure 7: Patent US 7891277 B2 Category II Saw – Right (Patent US7891277) .......................... 9 Figure 8: Makita LF1000 Flip-Over Saw – Left (Makita) .............................................................. 9 Figure 9: Patent US 20070234864 Flip-Over Saw – Right (Patent US20070234864)................... 9 Figure 10: Device in Circular Saw Mode ..................................................................................... 11 Figure 11: Device in Miter Saw Mode ......................................................................................... 11 Figure 12: Device in Table Saw Mode ......................................................................................... 11 Figure 13: Alignment Pins for Circular Saw ................................................................................ 12 Figure 14: Latching Mechanism for Circular Saw ....................................................................... 13 Figure 15: Table Flipped to Chop Saw Mode – left ..................................................................... 15 Figure 16: Table Flipped to Table Saw Mode – right ................................................................... 15 Figure 17: Ball Detent Ratchet Wrench Mechanism (FIELD OF THE INVENTION) ............... 15 Figure 18: Gas Shock (PPL Motor Homes) .................................................................................. 16 Figure 19: Raising and Lowering Table Saw Blade Mechanism ................................................. 16 Figure 20: Length of Cut Diagram................................................................................................ 18 Figure 21: Travel Length Diagram ............................................................................................... 19 Figure 22: Bevel Adjustment of Chop Saw (Amazon.com) ......................................................... 20 Figure 23: Successive Slides Illustration – Fully Extended (Left) ............................................... 21 Figure 24: Successive Slides Illustration – Fully Collapsed (Right) ............................................ 21 Figure 25: Solid Aluminum Turntable (Left) ............................................................................... 22 Figure 26: Steel Reinforced Turntable (Right) ............................................................................. 22 Figure 27: Radial Arm Free Body Diagram ................................................................................. 22 Figure 28: Table Saw Cut Depth and Deflection vs. Thickness ................................................... 23 Figure 29: Mechanism to Raise and Lower Blade ........................................................................ 24 Figure 30: Linkage Development Sketch ..................................................................................... 25 Figure 31: CAD Model in Miter Saw Mode – Top Left ............................................................... 27 Figure 32: CAD Model in Table Saw Mode – Top Right ............................................................ 27 Figure 33: Beveled and Mitered Prototype – Bottom Left ........................................................... 27 Figure 34: First Prototype in Miter Saw Mode – Bottom Right ..................................................