Elements and their Graphical Symbols

MechDesigner uses symbols to represent different elements in the graphic-area.

You can change the size of symbols with Application Options | Accessibility > Graphics

Symbols in the Graphic Area


Planes in the Model-Editor.

The model has three fixed Planes in the Model-Editor.

Model Axes in the Model-Editor

The model shows the fixed Red, Green and Blue axes. They locate the Origin of the Model.


Planes in the Mechanism-Editor.

The axes on each Plane show its orientation.

The smaller Red, Green and Blue axes are the X, Y, and Z-axes, respectively.

The axes intersect at the Origin of the Plane.


Part-Outlines: Added Parts and Base-Part

The Part-Outline is the symbol for a Part.

To edit a Part, you must select the Part-Outline.

The Part-Outline symbol for an Added-Part is an ovalRed-14-1b
The Part-Outline symbol for the Base-Part is a rectangleRed-14-2.

Each Part has its local x-axis and y-axis. They are at the start-Point of the Part.

Each added-Part has a CAD-LineRed-14-3 from its start-Point to its end-Point.


Part-Outlines:  solved and unsolved Parts

The Part-Outline can have two colours:

The Part-Outline is GreenRed-14-1b when it is a Solved Part. It has zero degrees-of-freedom

Other terms for a Solved Part are a kinematically-defined Part, or a Green Part.

The Part-Outline is BlueRed-14-2 when it is an Unsolved Part

Other terms for an Unsolved Part are: free Part, and Blue Part.


Pin-Joint in the Mechanism-Editor

When you Add Pin-Joint, you select a Point in two Parts.

The symbol for a Pin-Joint between Points in

an Added-Part and the Base-Part is a Position symbol'Red-14-1b.
two Added-Parts is a circleRed-14-2 that is slightly larger than Point symbol


Slide-Joint in the Mechanism-Editor

When you Add Slide-Joint, you select a Line in two Parts.

This symbol for a Slide-Joint between Lines is:

a narrowRed-14-1b rectangle alongone of the Lines
a wideRed-14-2 rectangle along the other Line
a small arrowheadRed-14-3. It is the 'positive' direction of the slide-joint.


Part-Axes in the Mechanism-Editor

The Part-Axes symbols are 'small' in a Mechanism-Editor.

The Axes of the Base-PartRed-14-1b are at the Origin of Mechanism-Plane
The Axes of an Added-PartRed-14-2 are at the start-Point of the CAD-Line.


Part Axes in the Part-Editor

The Part-Axes symbols are 'large' in the Part-Editor.

The X-axis is Orange
The Y-axis is Light Green

The length of the CAD-Line maybe longer or shorter than the X-axis.

If you zoom-in, the CAD-Line will appear to become longer relative to the axes.


Point Symbols

In the Mechanism-Editor: Points may be BlueRed-14-1b (Not solved), or GreenRed-14-2 (solved)
In the Part-Editor: Points may be BlueRed-14-2 (Not defined), or BlackRed-14-4 (defined)


'+' : centre-Points (centre of Arcs and Circles)

'O' : start-point or end-point of Lines or Arcs.

'CirclePlus' : start-Point or end-Point that is coincident with a centre-Point

Points that are Not Locked

Not Locked

Points that are Locked


The 'Locked Point' Symbol

When you use the Point Vectors and Location dialog to 'Lock and Specify' a Point in a Part, the Points show as 'Small Dowel Symbols'.

Velocity and Acceleration Vectors

A Vector Symbol

You can show vectors in the graphic-area when you:

Use the Point: Vector Display and Location dialog-box to show the Velocity-Vector and Acceleration-Vectors of a Point.
Use Force Calculations and show the Force-Vectors and Torque-Vectors.


Function-Block input-connector and output-connector Symbols

Function-BlocksRed-14-1b are a graphical icons that represent their function.

The input-connectorsRed-14-2 are to the left-side of the Function-Blocks.
The output-connectorsRed-14-3 are to the right-side of the Function-Blocks.
WiresRed-14-4 are from an output-connector to an input-connector.


Motor Symbol

When you show Forces, the Motor SymbolRed-14-1b that drives a Joint is the 'Power Source'.
This image shows the Motor at a Pin-JointRed-14-2.
You can move the Motor to a different joint, as required.



The Spring FB element has three symbols in the graphic-area:

Symbol Red-14-1b: FB - see below Spring FB connectors

Symbol Red-14-2: Spring between the anchor-points

Symbol Red-14-3: Dimension between the anchor-points.


Ball-Joint and Connecting-Part Symbol

The Ball-JointRed-14-1b has its own symbol.
Edit its radius in the Ball-Joint dialog-box.
The Connecting-PartRed-14-2 symbol replaces the Part-Outline when you join a Part to a different Part with two Ball-Joints.


Mass Symbol

Profile Mass: When you add a Profile, the Extrusion has Mass. A small dowel symbol shows at the Centre-of-Mass of each ProfileRed-14-2.
Total MassRed-14-1b: When you show Forces, the Centre-of-Mass Symbol is a small dowel. The Total Mass is given near to the Centre-of-Mass symbol. The colour of the symbol is the same as the Part-Outline, which becomes a random colour when you Display Forces.
Total Mass = Mass of Extrusions + Mass of Imported Solid + Mass of User Defined Mass.


2D-Cam Contact PointsRed-14-1b

When you add a 2D-Cam, the Contact points between the Cam and the Cam Follower are shown as small dowel symbols.

If these Points do not delete when you delete a cam, then edit the Cam-Part, and delete them.



The Symbol for a Motion-Point is a small triangle inside a small circle.

The circle is slightly smaller than the standard symbol for a Point.



The Symbol for a Gear is two involute Gears, Red-14-1bRed-14-2

The Gear-Pair is a kinematic-element - it transmits motion from its input part to the output-part.

You can edit the number-of-teeth, and other parameters.



The Symbol for a Driving PulleyRed-14-1b is a different default colour to a Driven PulleyRed-14-2

See Application Settings Graphics > Display colours.

A Belt can drive the Pullets, or a Pulley can drive the Belt.

Why is the Base-Part not Green when I had a Mechanism-Editor?


The Base-Part is a Random colour.

If the Base-Part is a not Green:

Icon-Force-Vectors-Show Forces toolbar > Display Forces is Show Force Vectors.

When this icon is set to display Force Vectors, each Part is given a random colour.

To make the Part Green, you should:

Icon-Force-Vectors-HideClick the Forces toolbar >Display Forces to Hide Force Vectors

When the icon is gray the Base-Part should be Green.

Why can I not see the Base-Part properly?

BasePart partial hidden by a Plane.

BasePart partial hidden by a Plane.

The Base-Part is being hidden by a Plane.

This is because:

Icon-ShowModelinMechVisibility toolbar > Show Model in Mechanism is Show Model

When the Model is being shown in the Mechanism, we also show the Planes.

You can:

Icon-Visibility-ModelinMech-HideClick Visibility toolbar > Show Model in Mechanism to Hide Model


- or -

Icon-DispFilt-PlanesClick Display toolbar > Display Planes to Hide Planes


Why is the Base-Part Grey?



The Base-Part is being hidden by the Base-Part in a Mechanism-Editor that is front of the active Mechanism-Editor

Icon-Visibility-Other Mech-SHOW Visibility toolbar > Show other Mechanisms is Show Other Mechanism

When this is set to Show Other Mechanisms, it also shows Other Part-Outlines in other Mechanisms, and, if:

a different Mechanism-Editor may be in front of the active Mechanism-Editor. The Base-Part of the other Mechanism-Editor will show in front to the Base-Part in the active Mechanism-Editor. If you spin the model you will be able to see the Base-Part of the active Mechanism-Editor.
two Mechanism-Editors are coplanar. Then you must Hide other Mechanisms

Tutorials and Reference Help Files for MechDesigner and MotionDesigner 14.2 + © Machine, Cam, Mechanism, and Motion Design Software by PSMotion Ltd