To use different method of the user-interface to delete an element. In this case we will delete a Pin-Joint using the Selection-Window, Assembly-Tree and the Kinematic-Tree.
Introduce, the R-R-R Dyad
To replace a Pin-Joint with a Slide-Joint.
➢ | Delete a Pin-Joint using different procedures |
➢ | Add a Slide-Joint |
After this step, in the Kinematics-Tree, the R-R-R Dyad becomes an R-R-P Dyad.
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This part of the tutorials shows you how to delete an element from different areas of the interface.
In this case we delete a Pin-Joint, using contextual-menus, form the:
Note: It is also possible to delete joints in the graphic-area if you click it and the press with the 'delete' key on your keyboard.
When you click one or more elements in the graphic-area, Assembly-Tree or Kinematics-Tree, they show in the Selection-Window. You can delete the element using the Selection-Window. Here, the element we will delete is a Pin-Joint. |
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Look in the Selection-Window. |
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It is possible, and even likely, that you will select more than one element. In this case, we have clicked the Pin-Joint and a CAD-Line.
A contextual-menu shows.
You will delete the Pin-Joint. |
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After you delete the Pin-Joint, you will see that the Part-Outlines of the Parts become Blue. Blue Parts are not kinematically-defined. Notes: MechDesigner will also delete the Motion-Dimension FB - it is bug!
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Because we delete the Motion-Dimension FB when we delete the Pin-Joint - which is a bug - we will add it again now.
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First, we will replace the Pin-Joint that we deleted above. Note: Occasionally, you can only make a Part-Outline red if you hover above the arc near the start-Point of the Part. |
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In the graphic-area, you can see the Pin-Joint is in the model again. The Parts are Green Parts again. Parts with Green Part-Outlines are Kinematically Defined Parts, again.
Here Pin-Joint7 - see Note 2 below.
In the image to the left, we can see the Part-Outlines of the Parts have become Blue. The Parts are now not kinematically-defined.
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Because we delete the Motion-Dimension FB when we delete the Pin-Joint - which is a bug - we will add it again now.
Click |
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The Parts-Outlines are now Green, again, as they are now kinematically-defined. |
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You can see the list of three Pin-Joints and two Parts.
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The Pin-Joint is in the Selection-Window.
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Again, you will see, as in the image to the left, the Part-Outlines are Blue (see Step 2.1) Blue Parts are not kinematically-defined.
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Because we delete the Motion-Dimension FB when we delete the Pin-Joint - which is a bug - we will add it again now.
Click |
The kinematic-chain in the model has Pin-Joints only. To remind us:
Imagine Point 1 is the Bearing Shaft (on Part 1), and Point 2 is the Bearing Housing (on Part 2). Introducing the Slide-Joint
Imagine Line 1 is a Slide-Rail (on Part 1), and Line 2 is a Slide-Block (on Part 2) |
To add a Slide-Joint, we need a Line in two different Parts. We are going to add a Slide-Joint between an Added-Part and the Base-Part. We will use:
Note: We can use any Line we add to a Part and the Base-Part. |
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When the Line is fully defined - Green in my colour scheme to the left.
To exit the Part-Editor, we can use the Edit Part icon above the Geometry toolbar (left of Graphic-area).
Note: The Base-Part The Lines |
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A Slide-Joint needs two Lines.
See the mouse-pointer in the image to the left. The Lines are now collinear. There is a Slide-Joint (see below: The Slide-Joint in the Graphic-Area) The Slide-Joint has replaced the Pin-Joint.
We look at Dyad Closures in much more detail in the next STEP 2.4 Dyad Closures There are four possible closures when you add the Slide-Joint:
Do 1-3 again, and again, until the Parts are in the same position as the image to the left.
The Parts that were in the R-R-R Dyad are now in an R-R-P Dyad. The three Joints in the R-R-P Dyad are:
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There are a three symbols to represent a Slide-Joint. In the image we can see:
The arrow-head shows the Positive Direction of the Slide-Joint. The Positive Direction is important if you want to add a Motion-Dimension with the Slide-Joint. |