rojo/.cursor/rules/roblox/en-us/physics/constraints/spring.md

title	description
Spring	SpringConstraint applies a force on its attachments based on spring and damper behavior, with an optional minimum/maximum length.

For an overview on creating, visualizing, and simulating mechanical constraints, including `Class.SpringConstraint`, see [Mechanical constraints](../../physics/mechanical-constraints.md). Also see [Roblox units](../../physics/units.md) to understand how Roblox units compare to metric units.

A Class.SpringConstraint applies a force on its attachments based on spring and damper behavior. You can customize a spring's damping and stiffness, as well as set minimum and maximum limits on the spring's length.

Free length

Class.SpringConstraint.FreeLength|FreeLength defines the natural resting length of the spring. If the attachments are further apart than the free length, they are forced together; if the attachments are closer together than the free length, they are forced apart.

Damping

The Class.SpringConstraint.Damping|Damping value controls how fast the spring's oscillation dies down. A value of 0 allows the spring to oscillate endlessly, while higher values bring the spring to a rest more quickly.

Stiffness

Class.SpringConstraint.Stiffness|Stiffness sets the strength of the spring. Higher values create a spring that responds with more force when its attachments are closer together or further apart than Class.SpringConstraint.FreeLength|FreeLength.

Stiffness = **25**

Stiffness = **500**

Limits

Enabling the Class.SpringConstraint.LimitsEnabled|LimitsEnabled property exposes the Class.SpringConstraint.MinLength|MinLength and Class.SpringConstraint.MaxLength|MaxLength values for setting the minimum and maximum length of the spring. If the spring's attachments reach these limits, they stop moving apart from one another without restitution.