About Joints

A Kinematic Joint specifies the relative movement between two Parts.

The joints we have are Pin-Joint, Slide-Joint and Ball-Joint.

Objective of this Step

1.Add your first Joint
2.Learn that a Joint is always between two Parts.

Summary of this Step

1.Click Add Pin-Joint
2.Click a:
Point in the Base-Part (Step 1.3)

and a

Point at the Origin of the new Part (Step 1.2)

Note: When the model becomes large and complex:

You need to click the two points two times - the first time to 'wake up' a point, and the second time to select it.
After you click the two Points, you must click the graphic area to pull the two points together as a Pin-Joint.


This help file uses the term 'Pin-Joint'.

Other terms you may know for a Pin-Joint are: Pivot-Point, Hinge-Point, Revolute Joint, Shaft Centre...

Video of this Step

How to...Add a Pin-Joint between two Points

Step-by-Step Instructions: Add a Pin-Joint

Add Pin-Joint icon

Expand the vertical Kinematic-elements toolbar to the LEFT-SIDE of the graphic-area.

STEP 1: Click Kinematic-elements toolbar > Add Pin-Joint
- or -
Click Add menu >  Mechanism sub-menu > Add Pin-Joint


The cursor [mouse-pointer] changes to Add Pin-Joint.

The Command-Manager in the Project-Explorer instruction is:

In the graphic-area: select a Point from two separate Parts. The Points are made coincident. The Parts can only pivot around each other.


STEP 2: Click the Point at the Origin of the Added-Part

It is best to click the Point at the Origin of the new Part when the Part is to become a 'Crank'.

'Added-Parts' always have two Points: one at each end of the CAD-Line along its centre.

You can add more CAD-Lines and Lines with the Part-Editor, of course.


STEP 3: Click a Point at one end of the Line in the Base-Part



1.The first element (in this command, a Point) MUST remain RED as you click the second element (in this command, a different Point in a different Part).
2.If you click the second element but actually miss it, MechDesigner cancels the first element you click.
3.You MUST click the two Points again.


The Point in the Added-Part snaps to the Point in the Base-Part.

You may need to click the graphic-area to complete the command.

To cancel the Add Pin-Joint command, do one of the following:

Click Add Pin-Joint in the Geometry toolbar to the left-side of the grahic-area

- or -

Right-click in the graphic-area

Note: the contextual sensitive command-palette appears at the same time when you right-click in the graphic-area.

- or -

Use the ESC key

-or -

Select a different command

Tutorial and Reference Help Files for MechDesigner and MotionDesigner 13.2 + © Machine, Mechanism, Motion and Cam Design Software by PSMotion Ltd