Universal

Note

For an overview on creating, visualizing, and simulating mechanical constraints, including UniversalConstraint, see Mechanical constraints. Also see Roblox units to understand how Roblox units compare to metric units.

A UniversalConstraint ensures two axes on two assemblies remain perpendicular. Example applications include vehicle power transmission to the rear drive shafts, robotics, and more.

Orientations

Orientation of a universal's two attachments affects how it will move. To ensure it behaves correctly, the SecondaryAxis of the attachments, visualized by the orange arrows, should be perpendicular to each other. Note that a green L-shaped indicator appears when the axes are properly oriented.

Axes Perpendicular

<img src="https://prod.docsiteassets.roblox.com/assets/physics/constraints/Universal-Attachments-Correct.jpg" width="672" height="378" alt="Secondary axes perpendicular for correct behavior" />

Axes Misoriented

<img src="https://prod.docsiteassets.roblox.com/assets/physics/constraints/Universal-Attachments-Incorrect.jpg" width="672" height="378" alt="Secondary axes misoriented" />

Limits

Enabling the LimitsEnabled property exposes the MaxAngle limit to restrict tilt within a cone, as well as Restitution which defines the elasticity of the attachments when they reach the limit.