390 lines
10 KiB
Plaintext
390 lines
10 KiB
Plaintext
freeCAD: 3D CAD with Motion Simulation by askoh.com
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Assembly
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Notes
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(Text string: 'CAD: Copyright (C) 2000-2004, Aik-Siong Koh, All Rights Reserved.<n><n>The piston crank is the most common mechanism to convert rotary motion to reciprocating motion or vice versa. A crank connects to the ground with a revolute joint. Its other end is connected to the connecting rod. And the connecting rod is connected to the piston which slides along an axis on the ground. The crank is given rotary motion causing the piston to slides back and forth is a straight line. Units are SI units. Angles are in radians.<n><n>If the instructions below are too brief, refer to the Notes in projectile.asm and circular.asm.<n><n>To load the example for a quick look:<n>Click File/Open/Assembly/ to get a dialog. Enter *.asm for a list of assemblies. Select piston.asm. <n><n>To create the assembly from scratch:<n>To create crank, connection rod and piston:<n>Create an empty assembly and populate it with two rods (Assembly1Part1, Assembly1Part2) and one cylinder (Assembly1Part3). The rods have dimensions (1.0d, 0.2d, 0.1d) and (1.5d, 0.2d, 0.1d). The cylinder has radius (0.5d) and height (1.0d). Arrange them from bottom up away from the origin. <n><n>To mark joint attachment points:<n>On the ground, create a marker (Assembly1Marker1) at (0.0d, 0.0d, 0.0d) and another (Assembly1Marker2) at (3.0d, 0.0d, 0.0d). <n>On the first rod, create a marker (Assembly1Part1Marker1) at (0.1d, 0.1d, 0.0d) and another (Assembly1Part1Marker2) at (0.9d, 0.1d, 0.0d) relative to the z-face. <n>On the second rod, create a marker (Assembly1Part2Marker1) at (0.1d, 0.1d, -0.1d) and another (Assembly1Part2Marker2) at (1.4d, 0.1d, -0.1d) relative to the z-face. <n>On the cylinder, create a marker (Assembly1Part3Marker1) at (0.0d, 0.0d, 0.0d) and another (Assembly1Part3Marker2) at (0.0d, 0.0d, -1.0d) relative to the z-face. Tilt the cylinder a little to get a good view of (Assembly1Part3Marker2). RightClick/Rotate/ over it to rotate the marker (90.0d) degrees about the x-axis.<n>Tilt the cylinder upright to help the solver assemble the system later.<n><n>To create the joints:<n>Connect (Assembly1Marker1) to (Assembly1Part1Marker1) with revolute joint (Assembly1Joint1).<n>Connect (Assembly1Part1Marker2) to (Assembly1Part2Marker1) with revolute joint (Assembly1Joint2).<n>Connect (Assembly1Part2Marker2) to (Assembly1Part3Marker2) with revolute joint (Assembly1Joint3).<n>Connect (Assembly1Marker2) to (Assembly1Part3Marker1) with translational joint (Assembly1Joint3).<n>The translational joint keeps the marker z-axes parallel and colinear. Only relative translation along the z-axis is permitted.<n><n>To apply motion to the crank:<n>Apply rotation motion (Assembly1Motion1) to (Assembly1Joint1). Enter 2.0d*pi*time.<n><n>The assembly is now ready for simulation, animation and plotting.<n>' runs: (Core.RunArray runs: #(514 63 14 5 12 1 2 37 89 10 4 36 1 43 295 32 848 21 517 29 151) values: #(nil #underline #(#underline #bold) #underline #(#underline #bold) #underline nil #(#bold #large) nil #bold nil #(#bold #large) nil #bold nil #bold nil #bold nil #bold nil)))
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Name
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Assembly1
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Position3D
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0.0 0.0 0.0
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RotationMatrix
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1.0 0.0 0.0
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0.0 1.0 0.0
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0.0 0.0 1.0
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Velocity3D
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0.0 0.0 0.0
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Omega3D
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0.0 0.0 0.0
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RefPoints
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RefPoint
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Position3D
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0.0 0.0 0.0
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RotationMatrix
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1.0 0.0 0.0
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0.0 1.0 0.0
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0.0 0.0 1.0
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Markers
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Marker
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Name
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Marker1
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Position3D
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0.0 3.0 0.0
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RotationMatrix
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1.0 0.0 0.0
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0.0 0.0 1.0
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0.0 -1.0 0.0
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RefPoint
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Position3D
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0.0 0.0 0.0
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RotationMatrix
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1.0 0.0 0.0
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0.0 1.0 0.0
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0.0 0.0 1.0
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Markers
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Marker
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Name
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Marker2
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Position3D
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0.0 0.0 0.0
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RotationMatrix
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1.0 0.0 0.0
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0.0 1.0 0.0
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0.0 0.0 1.0
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RefCurves
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RefSurfaces
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Parts
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Part
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Name
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Part1
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Position3D
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-0.1 -0.1 -0.1
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RotationMatrix
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1.0 0.0 0.0
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0.0 1.0 0.0
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0.0 0.0 1.0
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Velocity3D
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0.0 0.0 0.0
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Omega3D
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0.0 0.0 0.0
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FeatureOrder
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Extrusion
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zStart
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0.0
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zEnd
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0.1
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Sketch
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Name
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Sketch1
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Position3D
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0.0 0.0 0.0
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RotationMatrix
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1.0 0.0 0.0
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0.0 1.0 0.0
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0.0 0.0 1.0
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Graphics
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Rectangle
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Position2D
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0.0 0.0
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Angle
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0.0
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xLength
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1.0
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yLength
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0.2
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PrincipalMassMarker
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Name
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MassMarker
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Position3D
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0.5 0.1 0.05
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RotationMatrix
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1.0 0.0 0.0
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0.0 1.0 0.0
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0.0 0.0 1.0
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Mass
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0.2
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MomentOfInertias
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8.3333333333333e-4 0.016833333333333 0.017333333333333
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Density
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10.0
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RefPoints
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RefPoint
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Position3D
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0.0 0.0 0.1
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RotationMatrix
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1.0 0.0 0.0
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0.0 1.0 0.0
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0.0 0.0 1.0
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Markers
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Marker
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Name
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Marker1
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Position3D
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0.1 0.1 0.0
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RotationMatrix
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1.0 0.0 0.0
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0.0 1.0 0.0
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0.0 0.0 1.0
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RefPoint
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Position3D
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0.0 0.0 0.1
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RotationMatrix
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1.0 0.0 0.0
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0.0 1.0 0.0
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0.0 0.0 1.0
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Markers
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Marker
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Name
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Marker2
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Position3D
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0.9 0.1 0.0
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RotationMatrix
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1.0 0.0 0.0
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0.0 1.0 0.0
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0.0 0.0 1.0
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RefCurves
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RefSurfaces
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Part
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Name
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Part2
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Position3D
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0.94036115973815 -0.017284236661228 6.9388939039072e-18
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RotationMatrix
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-0.61538461538462 -0.78822698199689 -2.4430659816416e-17
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0.78822698199689 -0.61538461538462 3.1292471039841e-17
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-3.9699822201676e-17 -4.8559383484174e-33 1.0
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Velocity3D
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0.0 0.0 0.0
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Omega3D
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0.0 0.0 0.0
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FeatureOrder
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Extrusion
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zStart
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0.0
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zEnd
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0.1
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Sketch
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Name
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Sketch1
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Position3D
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0.0 0.0 0.0
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RotationMatrix
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1.0 0.0 0.0
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0.0 1.0 0.0
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0.0 0.0 1.0
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Graphics
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Rectangle
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Position2D
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0.0 0.0
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Angle
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0.0
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xLength
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1.5
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yLength
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0.2
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PrincipalMassMarker
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Name
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MassMarker
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Position3D
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0.75 0.1 0.05
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RotationMatrix
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1.0 -2.7755575615629e-16 0.0
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2.7755575615629e-16 1.0 0.0
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0.0 0.0 1.0
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Mass
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0.3
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MomentOfInertias
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0.00125 0.0565 0.05725
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Density
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10.0
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RefPoints
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RefPoint
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Position3D
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0.0 0.0 0.1
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RotationMatrix
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1.0 0.0 0.0
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0.0 1.0 0.0
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0.0 0.0 1.0
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Markers
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Marker
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Name
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Marker1
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Position3D
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0.1 0.1 -0.1
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RotationMatrix
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1.0 1.6433823482157e-50 6.1629758220392e-33
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1.9277988905447e-49 1.0 1.055150120668e-32
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6.1629758220392e-33 8.8305116654985e-33 1.0
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RefPoint
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Position3D
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-7.0256300777061e-17 -1.0408340855861e-17 0.1
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RotationMatrix
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1.0 1.7347234759768e-18 -6.9388939039072e-18
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1.7347234759768e-18 1.0 0.0
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-6.9388939039072e-18 0.0 1.0
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Markers
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Marker
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Name
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Marker2
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Position3D
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1.4 0.1 -0.1
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RotationMatrix
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1.0 1.9417266172265e-33 1.873501354055e-16
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1.4257315131995e-48 1.0 4.1633363423443e-17
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-2.5673907444456e-16 -4.1633363423443e-17 1.0
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RefCurves
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RefSurfaces
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Part
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Name
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Part3
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Position3D
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1.8563657024101e-16 1.024695076596 -6.9385028492422e-17
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RotationMatrix
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1.0 1.7680967979307e-16 -2.2204460492503e-16
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2.2204460492503e-16 6.3228810015037e-17 1.0
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1.7680967979307e-16 -1.0 6.3228810015037e-17
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Velocity3D
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0.0 0.0 0.0
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Omega3D
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0.0 0.0 0.0
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FeatureOrder
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Extrusion
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zStart
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0.0
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zEnd
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1.0
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Sketch
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Name
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Sketch1
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Position3D
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0.0 0.0 0.0
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RotationMatrix
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1.0 0.0 0.0
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0.0 1.0 0.0
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0.0 0.0 1.0
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Graphics
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Circle
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Position2D
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0.0 0.0
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Angle
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0.0
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Radius
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0.5
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PrincipalMassMarker
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Name
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MassMarker
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Position3D
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-7.9328390680452e-18 2.9323172983667e-17 0.5
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RotationMatrix
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9.2444637330587e-33 1.0 -1.0785207688569e-32
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9.9703461330478e-65 1.0785207688569e-32 1.0
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1.0 -9.2444637330587e-33 0.0
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Mass
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7.6536686473018
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MomentOfInertias
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0.93243354610288 1.1040224936599 1.1040224936599
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Density
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10.0
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RefPoints
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RefPoint
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Position3D
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0.0 0.0 0.0
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RotationMatrix
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1.0 0.0 0.0
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0.0 -1.0 0.0
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0.0 0.0 -1.0
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Markers
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Marker
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Name
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Marker1
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Position3D
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0.0 0.0 0.0
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RotationMatrix
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1.0 2.1223636732195e-32 -2.4651903288157e-32
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-2.4651903288157e-32 -2.2204460492503e-16 1.0
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-1.1179465652456e-32 -1.0 -2.2204460492503e-16
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RefPoint
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Position3D
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1.0408340855861e-17 5.5511151231258e-17 1.0
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RotationMatrix
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1.0 -6.9388939039072e-18 6.9388939039072e-18
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-6.9388939039072e-18 1.0 0.0
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6.9388939039072e-18 0.0 1.0
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Markers
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Marker
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Name
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Marker2
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Position3D
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0.0 0.0 0.0
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RotationMatrix
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1.0 -4.1633363423442e-17 4.1633363423442e-17
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-4.1633363423442e-17 1.0 -4.9303806576313e-32
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4.1633363423442e-17 -3.6977854932235e-32 1.0
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RefCurves
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RefSurfaces
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KinematicIJs
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ConstraintSets
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Joints
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RevoluteJoint
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Name
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Joint1
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MarkerI
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/Assembly1/Marker2
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MarkerJ
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/Assembly1/Part1/Marker1
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RevoluteJoint
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Name
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Joint2
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MarkerI
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/Assembly1/Part1/Marker2
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MarkerJ
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/Assembly1/Part2/Marker1
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RevoluteJoint
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Name
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Joint3
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MarkerI
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/Assembly1/Part2/Marker2
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MarkerJ
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/Assembly1/Part3/Marker1
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CylindricalJoint
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Name
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Joint4
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MarkerI
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/Assembly1/Part3/Marker2
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MarkerJ
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/Assembly1/Marker1
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Motions
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AllowRotation
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Name
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Motion1
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MotionJoint
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/Assembly1/Joint1
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GeneralConstraintSets
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ForceTorques
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ConstantGravity
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0.0 -9.81 0.0
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SimulationParameters
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tstart
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0.0
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tend
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1.0
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hmin
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1.0e-9
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hmax
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1.0
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hout
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0.04
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errorTol
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1.0e-6
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AnimationParameters
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nframe
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26
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icurrent
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1
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istart
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1
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iend
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26
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isForward
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true
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framesPerSecond
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30
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