Today I made propellers animation start and end smoothly, instead of instantly. In my BP_Propeller Blueprint I used a Timeline node, where I specified a curve. In this case it ramps up in 2 seconds non-linearly.

Then I used that in my Event Graph.

I also learned how to make a global function by creating a Blueprint Function. I moved my RPM to Deg/s function converter, since it looks kind of reusable.