MechDesigner definition: a Slide-Joint makes a Line in a Part become co-axial (coincident) with a Line in a different Part. The two Parts can slide along relative to each other. IFTOMM Kinematic definition: a Slide-Joint makes an axis in one part become collinear with an axis in a different part, but allows the axes to slide relative to each other. |
Edit menu > Application-Settings > General tab > Theme Options > Active Theme: Charcoal Dark Slate, Edit menu > Application-Settings > Graphics tab > Display Colours : (Background : White) ; (Part-Unsolved : Blue) ; (Part-Solved: Green) ;( Joint-Solved : Green) ; (Joint-Unsolved : Blue) |
Kinematic Elements Toolbar : Add Slide-Joint icon (<<left of graphics-area) |
|
Menu : |
Add menu > Mechanism sub-menu > Add Slide-Joint |
Dialog-Box : |
None |
IMPORTANT: To correctly calculate reaction forces for a Slide-Joint: There is often more than one Slide-Rail and Slide-Bearing that run in parallel in your actual design. However, a Slide-Joint is constructed from a Line in two Parts, that are made collinear. The length and position of the Lines that define a Slide-Joint must be equivalent to the actual design. |
|
Slide-Joint in the graphic-area:
* Positive-direction becomes important when you add a Motion-Dimension FB to the Slide-Joint. |
|
See also: Add Pin-Joint, Add Ball-Joint, Add Motion-Dimension FB |
Before you can do add Slide-Joint you must have a minimum of two Parts, and a Line* in each Part. A minimum of one Part must be a free Part, which has a Blue Part-Outline.
In this image: line * Line or CAD-Line |
STEP 1: Click Add Slide-Joint
STEP 2: Click the two Lines:
STEP 3: Complete the command
|
|||||||||||||||||
Assembly-Tree A new Slide-Joint Kinematics-Tree In this image, the new Slide-Joint belongs to an Unsolved Mechanism . A Part in the Slide-Joint is not kinematically-defined, and has a Blue Part-Outline. |
![]() |
How to add a Slide-Joint |
Assembly-Tree A new Slide-Joint Kinematics-Tree In this case, the new Slide-Joint in an Unsolved-Mechs as the Part-Outline is Blue in the model above |
Frequently, a machine design has two or more Slide-Joints between three or more Parts We must decide which two Lines from which of two Parts we want to select for each Slide-Joint. For example: There are a total three Parts and we would like to join all three Parts to one sliding axis. We must add two Slide-Joints: If, say, Slide-Joint#1 is between Lines 1 & 2 (in Parts 1 & 2), there are two options for Slide-Joint#2: Option A: Slide-Joint#2 between Lines 3 & 1 (in Parts 3 & 1) Option B: Slide-Joint#2 between Lines 3 & 2 (in Parts 3 & 2) When to do Option A or Option B becomes important when you need to also add Motion-Dimension FBs to specify the motions of the two Parts. |
||||||||||||
Preparation for this example:
Note: A minimum of one Part must be a free Part. However, one Part, two Parts, or all three Parts may be free Parts. |
||||||||||||
|
||||||||||||
Note: The Slide-Joint does not need to be with the CAD-Line Generally, a Slide-Joint can be with any Line in a Part. |
||||||||||||
Notes: Now we have clicked a total of three Lines. The Slide-Joint is between two Lines only. Thus, there is ambiguity as to which two Lines you want for the Slide-Joint. 'Ambiguity': when MechDesigner is not sure which element to select. |
||||||||||||
Select-Elements dialog-box When there is ambiguity as to which two Lines you want to select, the Select Elements dialog-box opens. Top-tip If you can anticipate that there might be ambiguity as to which elements you need to select, we recommend:
In the Select-Elements dialog-box, the element at the top of the list is always the first element you select.
|
||||||||||||
When we follow our recommendation, the Line at the top of the list is CAD-Line We definitely want to select CAD-Line2 for the new Slide-Joint. The ambiguity is which Line from the other two Lines To select the Lines
Generally, mathematically, you can combine two elements from three elements in three possible ways. 1&2; 2&3; 3&1 However, MechDesigner will select only those elements that you can combine to add the new element. Thus, you can select:
- or -
|
||||||||||||
However, you cannot select:
Why? MechDesigner knows there is a Slide-Joint between these two CAD-Lines already. |
||||||||||||
In the Select-Elements dialog-box.
The Select-Elements dialog-box closes. The two Lines become collinear. If they do not become collinear...
The two Lines become collinear to add a new Slide-Joint, Now, there are two Slide-Joints and three Lines that are collinear. |