Hey,
The easiest way to achieve this would be to parent the cylinder to a null object and rotate this null instead. This way you only have to worry about rotating one axis (Z in your case) and the cylinder would maintain its 5° angle.
I don’t remember off the top of my head what null objects in UE4 are called, but you can basically use any object as parent as long as you set it to invisible.
I hope I understood your question correctly. 