Add Spring FB

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Add Spring FB

Add 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.

Add Spring FB

How to add :


1.Click Forces toolbar > Add Spring FB

2.Click two different Points - they will be the Anchor-Points -in two different Parts.

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


Spring FB : symbols in 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

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


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

Spring FB ConnectorsRed-14-1b


Top :

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

Bottom :

Total Force, Force-X, Force-Y acting on anchor-points.

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

Input a Force-Function, which we add to the Force that is defined by the Spring FB parameters.

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

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


The Spring FB can be in three different states.


State 1: The Spring FB is enabled.

The default state.


State 2: The Spring FB is not enabled.

To disable the Spring FB,

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

In the Spring FB dialog-box

2.Deselect the Enable Check-box.

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


State 3: The Spring FB 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 how to Configure Power Source