Extrude along curve - unexpected results

[Anonymous]

This happens when I extrude along a curve:

https://streamable.com/m7i11

I have attached the file too. Any ideas why? I can sort of see that maybe it's trying to close the loop or something? One person suggested reversing the curve but this doesn't work either.

Note: you'll notice that the curve is aligned with the center of one cylinder - this is intentional, because I intend to twist the curve and I want the outer tube to be the only one that gets twisted.

[Fovvl · Accepted solution]

The extruding goes with the center of the curve. So it takes it as one object and trying to make  the curve in the middle. You have to split those cilinders and extrude them separatedly, then it will goes exactly along the curve.