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CV (Constant Velocity) Inverse Crank is similar to the Y–Inverse Sinusoid Motion-Law. We urge you to use this motion-law in preference to the Y-Inverse Sinusoid. This segment can be used more than once in one machine cycle, whereas the Y-Inverse-Sinusoid can be used only one time. This segment is best explained by considering the X and Y motion components of a Point that is at the end of a rotating-Part or Crank. When a Crank rotates with Constant angular velocity, the motion of the Point at the end of the Crank is Simple-Harmonic-Motion when it is projected onto a Line (a Sine function). When you apply the CV-Inverse-Crank segment to a Crank, the motion of a Point at the end of the Crank that is projected onto a Line can be made to move with a constant linear velocity for a phase of the Crank's rotation. SEGMENT-EDITOR See the image Segment-Parameters You can set the: •Minimum Velocity •Rel Start •Rel End If you use the Flexible-Polynomial Segment before and after this segment, you can: •Use the Blend Control Button to make the End of the Flexible-Polynomial Segment match the start of this Segment. •Use the Blend Control Button to make the Start of the Flexible-Polynomial Segment match the end of this Segment. ![]() Segment-Parameters of the 'Constant-Velocity Inverse |
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![]() Svhematic to help you understand how to use the CV-Crank motion-law. |
Segment Editor : Segment-ParametersMinimum Velocity This is the angle, after the Base-Value The direction of the Constant-Velocity vector for Point *The Base-Value |
Rel. Start The angle, before from the Angle of Minimum Velocity Rel. End The angle, after the Angle of Minimum Velocity Note: The Crank rotates Counter-Clockwise when Rel. Start is a Negative # and Rel. End is a Positive # The Crank rotates Clockwise when Rel. Start is a Positive # and Rel. End is a Negative # The velocity of the Point Start Angle = ...to... End Angle = The linear velocity and the length •Segment-Width •Length of the Rocker/Crank •Segment-Parameters: Rel Start Angle and Rel End Angle. |
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![]() CV Inverse-Crank2 x |
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An example motion with four segments and two CV Inverse Crank Segment 1: Constant-Velocity Inverse-Crank •X-axis : 0 to 90º Segment Parameters are: •Angle of Minimum Velocity = 90º •Relative Start Angle = -30º •Relative End = 30º With these Parameters: •When X-axis = 0º ; Y–axis = 60º. •When X-axis =90 ; Y–axis = 120º Segment 2: Flexible-Polynomial •X-axis : 90 to 180º •Y-axis at Start P=120. V, A, J flow from the end of the Constant-Crank-Velocity Segment. •Y-axis at End 240º Segment 3: Constant-Velocity Inverse-Crank •X-axis : 180 to 270º Segment Parameters are: •Angle of Minimum Velocity = 270º •Relative Start Angle = -30º •Relative End = 30º With these Parameters: •When X-axis = 180º ; Y–axis = 240º •When X-axis =270 ; Y–axis = 300º Segment 4: Flexible-Polynomial •X-axis : 90 to 180º •Y-axis P at Start = 300º. V, A, J flow from the end of the Constant-Crank-Velocity Segment. •Y=axis at End = 420º. |