I checked if the the fan blade is rotating freely to my new purchased range hood (because of a previous bad experience with the same model). It does rotating freely but "it's wobbling" (the distances from the blade to the upper metallic frame is variable - 0.5 cm on the left blade site and 1 cm on the right). My questions is:

This is normal? It was done on purpose by design?

Again my range hood is brand new, just unpacked it and checked the fan blade.

Thank you

To better describe the question I'd like to add the following:

1)The bolt holding fan is tight.
2) The blade is rotating in a plane which is not parallel with the metallic frame, so always the left part of the blade is closer to the frame than the right part. I guess this kind of movement (rotation) cannot be called "wobbling", even the visual effect is of wobbling.

Thanks again,