Forces | Add Spring FB

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Forces | Add Spring FB

Spring FB

See also: Spring FB dialog-box

Use a Spring FB to add a force between two Points that are in two different Parts.

The Forces a Spring FB can exert include:

Spring Force - a force proportional to the difference of the distance between the Spring's Anchor-Point and its Free-Length.

Constant Force - a constant force that only pulls or only pushes the Spring's Anchor-Points, throughout the machine-cycle.

Coulomb Constant-Force - a constant force that acts in the opposite direction to the relative velocity between the Spring's Anchor-Point.

Drag-Force - a force that is proportional to the relative velocity between the Spring's Anchor-Points.

Drag-Force-Squared - a force that is proportional to the square of the relative velocity between the Spring's Anchor-Points.

See Spring FB dialog box to edit these parameters.


Anchor-Points :

The two(2) Points that define an axis through which the Force FB applies its Force.

Force element :

A Spring FB is a Force-Element.

Linear Motive Force :

The Spring FB can become the Power-Source. It will indicate the Equivalent Linear Force that is needed to drive a Kinematic-Chain.

A Linear Motor would need to provide this Force.


Forces toolbar > Add Spring FB

Menu :

Add menu > Forces sub-menu > Add Spring FB

Dialog-Box :

Spring FB dialog-box.

How to add :

1.Click Forces toolbar > Add Spring FB

2.Click in the graphic-area, two different Points in two different Parts.

The Spring FB and its symbol are now in the graphic-area.

The Points you select for the spring are its Anchor Points.


Spring FB : symbols in graphic-area.

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

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

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

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

Spring FB ConnectorsRed-14-1b


Top: Distance, Velocity, Acceleration of the dimension between the anchor-points.

Bottom: Total Force, Force-X, Force-Y between the anchor-points.

Input-Connectors - see more at Spring FB dialog-box

Add a user-defined Force Function

The data at the input-connector to the Spring must be Force units, (SI Newtons).

Convert any data-type and units with a Math FB, and use Force as the Output Data Type.

Positive (Negative) value will Pull (Push) the Anchor Points together (apart).


Spring FB in the graphic-area.

The Spring FB can be in three different states:

State 1: Spring FB is enabled

The default state.


State 2: Spring FB is not enabled

To disable the Spring FB,

1.Edit the Spring FB to open the Spring FB dialog-box

2.Deselect the Enable Check-box.

3.Click OK-tiny-11-15 to close the dialog-box.


State 3: It is a Linear Motor

To change the Spring as a Linear-Motor:

1.Edit a Kinematic-Chain to open the Configure Power Source dialog-box

2.Click the Motion-Dimension FB that applies to the kinematic-chain

3.Click the Spring as the Power Source, and it becomes a Linear Motor.

4.Close the Configure Power Source dialog-box.

See Configure Power Source