--- name: UniversalConstraint last_updated: 2026-06-11T23:11:57Z inherits: - Constraint - Instance - Object type: class memory_category: BaseParts summary: "Ensures two axes on two bodies remain perpendicular." --- # Class: UniversalConstraint > Ensures two axes on two bodies remain perpendicular. ## Description A **UniversalConstraint** ensures two axes on two bodies remain perpendicular. Contextually, this constraint is more restrictive than a [BallSocketConstraint](/docs/reference/engine/classes/BallSocketConstraint.md) but less restrictive than a [HingeConstraint](/docs/reference/engine/classes/HingeConstraint.md) by one degree of freedom. Example applications of this constraint include transmitting power between the transmission and drive shafts of cars, robotics, and more. When configuring this constraint, it may be helpful to study [Roblox Units](/docs/en-us/physics/units.md) to understand how Roblox units compare to metric units. #### Limits Enabling the [LimitsEnabled](/docs/reference/engine/classes/UniversalConstraint.md) property exposes the [MaxAngle](/docs/reference/engine/classes/UniversalConstraint.md) limit to restrict tilt within a cone, as well as [Restitution](/docs/reference/engine/classes/UniversalConstraint.md) which defines the elasticity of the attachments when they reach the limit. ## Properties ### Property: UniversalConstraint.LimitsEnabled ```json { "type": "boolean", "access": "ReadWrite", "security": { "read": "None", "write": "None" }, "serialization": { "can_load": true, "can_save": true }, "thread_safety": "ReadSafe", "category": "Universal", "capabilities": [ "Physics" ], "simulationAccess": true } ``` This property, when enabled, limits the relative angular motion of the primary axes of attachments through a cone constraint. The default value is false. ### Property: UniversalConstraint.MaxAngle ```json { "type": "float", "access": "ReadWrite", "security": { "read": "None", "write": "None" }, "serialization": { "can_load": true, "can_save": true }, "thread_safety": "ReadSafe", "category": "Limits", "capabilities": [ "Physics" ], "simulationAccess": true } ``` This property determines the max angle, in degrees, of the constraint's limiting cone, formed from [Attachment0](/docs/reference/engine/classes/Constraint.md) and its primary axis. The default value is 45 degrees. In order for this property to take affect, the constraint's [LimitsEnabled](/docs/reference/engine/classes/UniversalConstraint.md) property must be set to true. ### Property: UniversalConstraint.Radius ```json { "type": "float", "access": "ReadWrite", "security": { "read": "None", "write": "None" }, "serialization": { "can_load": true, "can_save": true }, "thread_safety": "ReadSafe", "category": "Appearance", "capabilities": [ "Physics" ], "simulationAccess": true } ``` This property indicates the constraint's visualization radius, in studs. Default value is 0.2. ### Property: UniversalConstraint.Restitution ```json { "type": "float", "access": "ReadWrite", "security": { "read": "None", "write": "None" }, "serialization": { "can_load": true, "can_save": true }, "thread_safety": "ReadSafe", "category": "Limits", "capabilities": [ "Physics" ], "simulationAccess": true } ``` This property determines the restitution of the two [Attachments](/docs/reference/engine/classes/Attachment.md) connected by the [UniversalConstraint](/docs/reference/engine/classes/UniversalConstraint.md) when they reach the end of the range specified by [MaxAngle](/docs/reference/engine/classes/UniversalConstraint.md). The value defaults to 0 and can be any floating number in the range of 0 to 1. Only applies when [LimitsEnabled](/docs/reference/engine/classes/UniversalConstraint.md) is set to true. ## Inherited Members ### From [Constraint](/docs/reference/engine/classes/Constraint.md) - **Property `Active`** (`boolean`): Indicates if the constraint is currently active in the world. - **Property `Attachment0`** (`Attachment`): The Attachment that is connected to - **Property `Attachment1`** (`Attachment`): The Attachment that is connected to - **Property `Color`** (`BrickColor`): The color of the constraint. - **Property `Enabled`** (`boolean`): Toggles whether or not the constraint is enabled. - **Property `Visible`** (`boolean`): Toggles the constraint's visibility. - **Method `GetDebugAppliedForce(bodyId: int): Vector3`**: *(deprecated)* - **Method `GetDebugAppliedTorque(bodyId: int): Vector3`**: *(deprecated)* ### From [Instance](/docs/reference/engine/classes/Instance.md) - **Property `Archivable`** (`boolean`): Determines if an Instance and its descendants can be cloned using - **Property `archivable`** (`boolean`): *(deprecated, hidden)* - **Property `Capabilities`** (`SecurityCapabilities`): The set of capabilities allowed to be used for scripts inside this - **Property `Name`** (`string`): A non-unique identifier of the Instance. - **Property `Parent`** (`Instance`): Determines the hierarchical parent of the Instance. - **Property `PredictionMode`** (`PredictionMode`): - **Property `RobloxLocked`** (`boolean`): A deprecated property that used to protect CoreGui objects. *(hidden)* - **Property `Sandboxed`** (`boolean`): When enabled, the instance can only access abilities in its `Capabilities` - **Property `UniqueId`** (`UniqueId`): A unique identifier for the instance. - **Method `AddTag(tag: string): ()`**: Applies a tag to the instance. - **Method `children(): Instances`**: Returns an array of the object's children. *(deprecated)* - **Method `ClearAllChildren(): ()`**: This method destroys all of an instance's children. - **Method `Clone(): Instance`**: Create a copy of an instance and all its descendants, ignoring instances - **Method `clone(): Instance`**: *(deprecated)* - **Method `Destroy(): ()`**: Sets the Instance.Parent property to `nil`, locks the - **Method `destroy(): ()`**: *(deprecated)* - **Method `FindFirstAncestor(name: string): Instance?`**: Returns the first ancestor of the Instance whose - **Method `FindFirstAncestorOfClass(className: string): Instance?`**: Returns the first ancestor of the Instance whose - **Method `FindFirstAncestorWhichIsA(className: string): Instance?`**: Returns the first ancestor of the Instance for whom - **Method `FindFirstChild(name: string, recursive?: boolean): Instance?`**: Returns the first child of the Instance found with the given name. - **Method `findFirstChild(name: string, recursive?: boolean): Instance`**: *(deprecated)* - **Method `FindFirstChildOfClass(className: string): Instance?`**: Returns the first child of the Instance whose - **Method `FindFirstChildWhichIsA(className: string, recursive?: boolean): Instance?`**: Returns the first child of the Instance for whom - **Method `FindFirstDescendant(name: string): Instance?`**: Returns the first descendant found with the given Instance.Name. - **Method `GetActor(): Actor?`**: Returns the Actor associated with the Instance, if any. - **Method `GetAttribute(attribute: string): Variant`**: Returns the value which has been assigned to the given attribute name. - **Method `GetAttributeChangedSignal(attribute: string): RBXScriptSignal`**: Returns an event that fires when the given attribute changes. - **Method `GetAttributes(): Dictionary`**: Returns a dictionary of the instance's attributes. - **Method `GetChildren(): Instances`**: Returns an array containing all of the instance's children. - **Method `getChildren(): Instances`**: *(deprecated)* - **Method `GetDebugId(scopeLength?: int): string`**: Returns a coded string of the debug ID used internally by Roblox. - **Method `GetDescendants(): Instances`**: Returns an array containing all of the descendants of the instance. - **Method `GetFullName(): string`**: Returns a string describing the instance's ancestry. - **Method `GetStyled(name: string, selector: string?): Variant`**: Returns the styled or explicitly modified value of the specified property, - **Method `GetStyledPropertyChangedSignal(property: string): RBXScriptSignal`**: - **Method `GetTags(): Array`**: Gets an array of all tags applied to the instance. - **Method `HasTag(tag: string): boolean`**: Check whether the instance has a given tag. - **Method `IsAncestorOf(descendant: Instance): boolean`**: Returns true if an Instance is an ancestor of the given - **Method `IsDescendantOf(ancestor: Instance): boolean`**: Returns `true` if an Instance is a descendant of the given - **Method `isDescendantOf(ancestor: Instance): boolean`**: *(deprecated)* - **Method `IsPropertyModified(property: string): boolean`**: Returns `true` if the value stored in the specified property is not equal - **Method `QueryDescendants(selector: string): Instances`**: Returns an array containing all descendants of the instance that match the - **Method `Remove(): ()`**: Sets the object's `Parent` to `nil`, and does the same for all its *(deprecated)* - **Method `remove(): ()`**: *(deprecated)* - **Method `RemoveTag(tag: string): ()`**: Removes a tag from the instance. - **Method `ResetPropertyToDefault(property: string): ()`**: Resets a property to its default value. - **Method `SetAttribute(attribute: string, value: Variant): ()`**: Sets the attribute with the given name to the given value. - **Method `WaitForChild(childName: string, timeOut: double): Instance`**: Returns the child of the Instance with the given name. If the - **Event `AncestryChanged`**: Fires when the Instance.Parent property of this object or one of - **Event `AttributeChanged`**: Fires whenever an attribute is changed on the Instance. - **Event `ChildAdded`**: Fires after an object is parented to this Instance. - **Event `childAdded`**: *(deprecated)* - **Event `ChildRemoved`**: Fires after a child is removed from this Instance. - **Event `DescendantAdded`**: Fires after a descendant is added to the Instance. - **Event `DescendantRemoving`**: Fires immediately before a descendant of the Instance is removed. - **Event `Destroying`**: Fires immediately before (or is deferred until after) the instance is - **Event `StyledPropertiesChanged`**: Fires whenever any style property is changed on the instance, including ### From [Object](/docs/reference/engine/classes/Object.md) - **Property `ClassName`** (`string`): A read-only string representing the class this Object belongs to. - **Property `className`** (`string`): *(deprecated)* - **Method `GetPropertyChangedSignal(property: string): RBXScriptSignal`**: Get an event that fires when a given property of the object changes. - **Method `IsA(className: string): boolean`**: Returns true if an object's class matches or inherits from a given class. - **Method `isA(className: string): boolean`**: *(deprecated)* - **Event `Changed`**: Fires immediately after a property of the object changes, with some