IMPORTANT: Background to this Step.
Parts have two states:
•Unsolved Parts : they are not kinematically-defined; they have Blue Part-Outlines
•Solved Parts : they are kinematically-defined; they have Green Part-Outlines; they have Zero(0) degrees-of-freedom.
Objective of this Step
After the last step, STEP 1.4, the state of the Part is unsolved.
It is free to rotate around the Pin-Joint.. It has one(1) degree-of-freedom.
We must change the state of the Part from unsolved to solved.
The Part is then kinematically-defined. It will then have zero(0) degrees-of-freedom.
Summary of this Step
Add a Motion-Dimension FB
Edit the Part's start position - its Base-Value.
Note: To edit the default colors for Solved Parts and Unsolved Part:
Application Settings > Graphics tab > Display colors > Part Solved to Green and Part Unsolved to Blue.
Video
Tutorial 1: Step 1.5 •Add a Motion-Dimension FB •Edit a Motion-Dimension FB |
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STEP 1: Click: |
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In the Command-Manager, we must select three elements We must select the three elements in the correct order (in sequence):
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 Command Manager ready for selections |
Click the elements
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 Commandd Manager with selections |
STEP 2: Click
The Motion-Dimension FB is now in the graphic-area.
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The Motion-Dimension FB element has two features in the graphic-area:
Note: There are two different mouse-actions: To move the FB To move the Motion-Dimension
Hover(FB)= move your mouse above the FB icon. DRAG = Mouse-Button-Down, and move your mouse-pointer, Mouse-Button-Up |
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Notes: •The color of the Part-Outline •The design of the icon in the graphic-area is different to the icon in the Motion-Dimension FB in the Kinematic-FB toolbar. •Its design is similar to a Pin-Joint, which is to help you see that the Motion-Dimension FB specifies the angle of a Part. |
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To edit the Part's initial position, we must edit its Base-Value parameter in the Motion-Dimension dialog-box. |
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 Motion-Dimension FB dialog-box |
1.Double-click the Motion-Dimension FB in the graphic-area In the Motion-Dimension dialog-box: 2.Edit: oBase-Value The angle of the Motion-Dimension when a wire is not connected to the input-connector of the Motion-Dimension FB. - or - oBase-Value The current positional value of the Motion-Part It is sometimes more useful to edit the current positional value than to edit its Base-Value. Directions It is possible to 'negate' the sense of the Base-Value and the Motion-Values Notes: There are two parts to the Motion-Dimension in the graphic-area: There is the FB Icon and the Dimension. To move the: •Icon: Hover(FB) + Drag the Function-Block •Dimension: CTRL + Hover(FB) + Drag the Function-Block |
The Part, Pin-Joint and Motion-Dimension are the elements that make a Rocker. A Rocker is a Motion-Part. |
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If you explore the Kinematics-Tree, you can see the three elements that you need to give the Rocker kinematic-element. |
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 Kinematic-Tree with Elements for a Rocker |
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Part |
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Pin-Joint |
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Mot-Dim Rocker |
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•Degrees-of-Freedom (DOF) The number of coordinates that you need to specify the position and orientation of a Part. •Mobility oMobility = Degrees-of-Freedom – Number of Motion-Dimensions •Motion-Parts: oRocker: a Part joined with a Pin-Joint to a kinematically-defined Part. The angle of the Rocker is given by a Motion-Dimension FB. oSlider: a Part joined with a Slide-Joint to a kinematically-defined Part. The position of the Slider is given by a Motion-Dimension FB. •Kinematically-Defined Part: a Part that is a child to a kinematically-defined chain •Kinematically-Defined Chain: a kinematic-chain that has Mobility equal to Zero. •A Completely Free-Part has three degrees-of-freedom (on a Plane) •A Pin-Joint removes two degrees-of-freedom. •A Motion-Dimension removes one degree-of-freedom. •3 – 2 – 1 = 0 ( DOFs ) |