Extension Spring Component Generator dialog box

Sets parameters for design of an extension spring.

Access:

Ribbon: Design tab

Spring panel

Extension

Spring Reference Image

Click to display an image with the basic spring dimensions.

The image updates when the spring diameter is changed to Inner, Median, or Outer.

The image does not update for changes in length, hook type, hook length, spring diameter value or wire diameter.

Model

Use this section to specify a placement options, and the type of spring loaded state.

Note: When the full placement is specified, the graphical preview with appropriate dimensions, and spring type is created.

Installed Length	Min. Load angle between arms is set based on the minimum deflection of working arm.
	Work Load angle between arms is set based on the maximum deflection of working arm.
	Max. Load angle between arms is calculated based on working force.
	Custom angle between arms is set by a user.
Min., Work, Max. Custom Load Length	This edit field changes according to the load selected in the previous drop-down menu. Enter or measure the spring length.
Coil Direction	Select the direction of the coil, left or right.

Spring Wire

Enter or measure the wire diameter value.

Spring Diameter

Use the drop-down list to specify which spring dimensions are the inputs for the calculation, and which dimension is calculated.

Outer - Mean and inner spring diameters are calculated for the specified wire diameter and outside spring diameter.

Median - Inner and outside spring diameters are calculated for the specified wire diameter and mean spring diameter.

Inner - Mean and outside spring diameters are calculated for the specified wire diameter and inside spring diameter.

Note: According to this selection the name of the following edit field changes to Inside Diameter, Mean Diameter, or Outside Diameter.

Start

The spring ends are typically the same on both ends. This is especially true for stock springs. However, you can select different start and end types for compression springs.

Hook Type	Use the drop-down menu to select type of start hook. See the Hooks of extension springs chapter in the Engineer's Handbook for hooks calculation formulas.
Hook Length	Enter the length of the hook. For Non-specified Hook Type, if you enter 0, the coil end is natural (no bend).

End

The spring ends are typically the same on both ends. This is especially true for stock springs. However, you can select different start and end types for compression springs.

Hook Type	Use the drop-down menu to select type of end hook. See the Hooks of extension springs chapter in the Engineer's Handbook for hooks calculation formulas.
Hook Length	Enter the length of the hook. For Non-specified Hook Type, if you enter 0, the coil end is natural (no bend).

Spring Length

Use this section to define which parameters are entered and which are calculated.

Length Inputs	n, o L₀	Calculates the loose spring length for the specified wire diameter, number of spring coils and shape and size of spring hook.
	L₀, o n	Calculates the number of spring coils for the specified wire diameter, length of unloaded spring and shape and size of spring hook.
	L₀, n o	Calculates the size of a spring hook for the specified wire diameter, number of coils and length of unloaded spring.
Loose Spring Length	Enter or measure the loose spring length value. Note: This option is available only if L₀, t n is selected in the Length Inputs drop-down list.
Total Hook Length	A sum of hook lengths o₁ and o₂. If you select the same hook type of both spring ends their lengths are the same (o₁ = o₂)
Active Coils Number	Specify the spring number of active coils.
Coil Pitch	Specify the coil pitch. Note: The edit filed is enabled if you select Without Pre-stress in the spring Pre-stress drop-down menu in the Calculation tab. Click next to the edit field to open the Pitch between Spring Coils dialog box where you can specify the value of the pitch between spring coils. Selected value transfers to the Design tab when you click OK. When the edit field is enabled, the value is calculated when you click Calculate.

Results

To display the Results area on the right side of the Calculation and Design tabs, double-click the double line on the right or click the chevron.

Results area displays appropriate results which need to be calculated to get all proper dimensions of spring. Click Calculate to display the values. The units of the results values can be changed. Double-click the specified value you want to change.

Following output parameters are displayed in the Results pane:

Spring Index (c)
Mean Spring Diameter (D)
Outside Spring Diameter (D₁)
Inside Spring Diameter (D₂)

Note: For further description of the calculated parameters in metric or English units, see Engineer's Handbook.

Summary of Messages

Displays the reports about calculation. To open the Summary of Messages area at the bottom of the Calculation and Design tabs, double-click the double line at the bottom of tabs or click the chevron at the bottom of the tabs.

Toolbar commands

Extension Spring Component Generator dialog box - Design tab