﻿ MechDesigner Reference & User Interface > 2.2 Mechanism-Editor: > Force elements > Add Force-Data FB

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.

STEP 1: Start the Add Force-Data FB command

STEP 2: Add a Force-Data FB to the graphic-area

 1.Click Forces toolbar > Add Force-Data FB - or - 1.Click Add menu > Forces sub-menu > Add Force-Data FB 2.Click in the graphic-area to place the Force-Data FB in the graphic-area.

The Force-Data FB is now in the graphic-area - see left

STEP 2.Open the Force-Data FB dialog

 1.Double-click the Force-Data FB to open the Force-Data FB dialog-box. - or -

STEP 3.Link the Force-Data FB to a Force-Element and a Point

A.Select a Force-Elements

 1.Click a Force-element in the graphic-area or the Assembly-Tree Force-elements include: Joint, 2D-Cam, Spring, Gear-Pair, Pulley, Rack-Pinion, •The Joint, 2D-Cam or Spring shows in the box •A list of Available Points shows in the box

B.Select a Point in the box of Available Points (see Note below)

 1.Click a Point in the box below. If you select a: •Pin-Joint - there are two(2) Available Points One Point on each Part of the Pin-Joint •Slide-Joint - there are four(4) Available Points Two Points on each Line of the Slide-Joint •2D-Cam - zero(0) Available Points Contact Point is selected •Spring FB - two(2) Available Points The Spring's Anchor Points •Rack-Pinion - two(2) Available Points The Contact-Points between the Rack and Pinion

Note: Even if a Point shows in the Selected Force Output Element box, click the Point in the Available Points box.

3.Click to close the Force-Data FB