Why won't the wheels on my train carriage blueprint spin?

My level is sent in the downtown of an Eastern Seaboard city, and one of the elements/hazards of this scene is an active over-road rail bridge with trains that run across it at random intervals. I’ve constructed the carriages themselves and got a timeline to move the carriages from one side of the map to the other before destroying them out of sight, but I can’t for the life of me figure out how to make the physics constraint on each of the wheel axes spin continuously while the train is in motion. I tried basic SetRotation nodes and loops, but they came back with infinite loop errors. I created a test blueprint to figure out how to rotate the wheels in the first place and that works fine, but the moment I splice the code from the test BP into the construction script of the finalised BP, it simply refuses to work.

I’ve taken screenshots of both the event graph and the construction script, in case the root of my problems lies in one or the other. Unless it’s a case of I’m an idiot and you can’t have timelines and physics constraints in the same blueprint.

Different angle: why not just use AddRotation() with the timeline? Or alternatively, RotationMovementComponent?

Try moving the Construction Script to BeginPlay(). Also, timelines do not need to be on Tick(); they’re ticking by default already. BeginPlay() suffices here as well.

Remove SetRelativeLocation() and set DeltaRotation to a value of your liking and you’re golden. (You might also be able to plug in an array of your wheels without needing a loop into your nodes, just for some cleanup)

DeltaRotation is basically how much rotation gets added per tick. If you’re interested about the technical aspects, you can look up World Delta Seconds online. That might be sensible since otherwise your delta values will vary based on game FPS.

So something like this? I tried to replicate the set location path 1:1 with rotation, but I couldn’t find all the nodes that did the same job as that path

Worked a treat, thanks. I thought initially I had to make my rotation sequence path as complex the vector path, but then again coding has never been my strong subject