A part that rides a part
Since the October 2026 update a part or a barrel can sit on another part. Spin the carrier and everything riding it goes round: moons, a lantern wheel, a chained tail, a gun ring that turns and fires.
What you see
A dark plate turns slowly under the body with two guns riding it, so the guns sweep round and fire as they go. Behind the tank a small planet spins with three yellow moons circling it. Nothing here is a turret or a drone: it is parts riding parts.
The trick
Before the update a part could ride a barrel or an auto turret, and that was all (lessons 05 to 09 are built on riding turrets). The editor update of 6 October 2026 added Rides on for parts: a part, or a barrel, can ride another part. Its Offset X, Offset Y and Angle are then measured from the carrier's centre, along the carrier's angle. Give the carrier Rotation: Spins and everything riding it orbits. A barrel that rides a part turns with it and still fires, which is how the game's change notes describe "a rotating gun ring".
Numbers that matter
| Field | Value | Notes |
|---|---|---|
| Carrier Spin speed | 0.02 to 0.05 | Rotation per tick; 0.02 is a turn in about 13 s, 0.05 one in 5 s |
| Rider Offset X | the orbit radius | Measured from the carrier's centre, along the carrier's angle |
| Rider Angle | 0, 120, 240 | Spaces riders evenly; the carrier's spin is added to all of them |
| Chain depth | 4 at most | A root part and four riders in a line; the editor clears a deeper link |
| Riders' hitbox | none | The import clears Collidable on a rider; tick it on the carrier instead |
Gotchas
- A rider draws under its carrier unless you place it over (the same rule as a part on a barrel). Moons under their planet are barely visible; the first version of this demo had exactly that problem.
- Rides on one thing. A part that rides a barrel or an auto turret cannot also ride a part; the editor keeps the barrel first, the turret second, the part third.
- The editor's tooltip on a riding barrel says "Looks only; it fires nothing". It does fire (seen in play, 6 October 2026). Give it Always fire if the ring should spray on its own.
- Nothing bends. A chained tail of riders turns as one piece when the root spins; for a tail that lags turns see lesson 06.
- The carrier can itself ride a turret or a barrel, so a spinning wheel can hang off a swinging arm.
Where to use it
Moons and electrons; a clock (two riders of different lengths on a slow hub, or two hubs at different speeds); lanterns, bells or gondolas on a wheel; a halo of motes that costs no budget because they are parts, not drones; an eye whose pupil rides the eyeball; and a gun ring that sprays as it turns.