Hello!
I think we all know the trick of creating a conveyor by setting the Velocity to a Vector3 and anchoring the part, but I’m looking to make a conveyor that is welded to a part that moves with TweenService (so the conveyor is unanchored).
How could I do that with a script (or how can I do that at all)?
Thanks in advance,
Mehdi
You can apply a BodyMover (like BodyPosition / BodyVelocity) to anyone that steps on top of the conveyor belt with either a Touched event, or setting a raycast from the player character’s torso downwards.
Vice versa, you can delete the BodyMover after the player has left the conveyor.
(hol up, doesn’t an unanchored conveyor already work with vector3 velocity even when it’s welded?)
I’ve never made a conveyor so no, I don’t know about this trick 
But Cadentopia is right, you can use a BodyMover off of a collision detection (Touched event) and can set some sort of BodyVelocity to the desired amount. Keep in mind that there are other options (BodyForce, BodyPosition) that can do different things depending on the effect you want.
If you want to avoid deleting bodymovers, I suggest just keeping one on the player at all times (with proper exploit measures taken, obviously) so you can combine effects for multiple conveyors. But honestly it’s up to you, there’s a lot of ways to do this sort of thing.