Slide-Joint :

A Slide-Joint forces a Line* in a Part to be collinear with a Line* in a different Part.

A Slide-Joint removes two degrees-of-freedom from the model.

A Slide-Joint lets a Part move relative to a different Part with a rectilinear translation motion.

Prismatic Joint :

The kinematic and equivalent term for a Slide-Joint.

Kinematics-Tree :

Joints in a Dyad use the letter P to represent a Slide-Joint. - for example: R-R-P dyad

* Line or CAD-Line.

Derived Names:

sliding-Part :

a Part that you join with a Slide-Joint to a different Part.

The symbol for a Slide-Joint:

* The Positive-Direction is important if you want to add a Motion-Dimension FB to the Slide-Joint.

See Positive direction of Slide-Joints and Motion-Dimension.

IMPORTANT: To calculate reaction Forces on a Slide-Joint:

The length and position of the Lines should be equivalent to actual length and position of the Slide-ways and Bearings.

STEP 1: Start the Add Slide-Joint command

STEP 2: Click the two(2) Lines

The two(2) Lines are collinear at the Slide-Joint.

The Positive Direction of the Slide-Joint is identified by the small arrowhead.

If the Select-Elements dialog opens, see Slide-Joint Special Case

Frequently, a machine design has two(2) collinear Slide-Joints between three Parts.

You must decide which two(2) Lines from which of two(2) Parts you want to select for each Slide-Joint.

For example:

There are a total three Parts. You must add two(2) Slide-Joints:

Slide-Joint#1 - joins Lines 1 and 2 (in Parts 1 and 2),

Slide-Joint#2: joins

Option A: Lines 3 and 1 (in Parts 3 and 1)

or

Option B: Lines 3 and 2 (in Parts 3 and 2)

Option A or Option B is important when you also add a Motion-Dimension FBs to control the motions of the two(2) Parts.

Preparation example:

STEP 1:Add Slide-Joint

STEP 2:Select two(2) Lines:

You have clicked a total of three(3) Lines.

However, the Slide-Joint is between two(2) Lines.

Therefore, there is ambiguity. Which two(2) Lines do you want for the Slide-Joint?

“Ambiguity” : when MechDesigner does not know which elements you want to select.

When there is ambiguity, the Select Elements dialog opens.

<<< Select-Elements dialog

STEP 3:Select the TWO Lines in the Select-Elements dialog

You can select:

You cannot select:

Why not CAD-Line and CAD-Line3 ?

STEP 5: Close the Select-Elements dialog

There are now two(2) Slide-Joint between three(3) Lines