I have just received my NN4 and I am a little uncertain where the washers should be placed. My NN4 package contains some metal and some plastic washers. At first I thought them to be spare parts.
While inspecting the NN I noticed, on the knob connecting the upper and the lower arm there is a metal washer followed imediatley by a plastic washer. Both washers are next to the plastic part of the knob and below the lower arm. A rubber ring on the thread prevents the knob from falling off.
The knob holding the CP-2 plate has just a little rubber ring attached. There are no washers on this knob. Since turning it feels a little "crunshy" I was wondering if some washers should be added there.
The exploded view from the manual is no help here since it looks quite different from my NN4. According to this view every knob has a metal washer and there are no plastic washers at all. Even the knob for the upper rotator (the one with the fixed 15 degree steps) got a metal washer. In my NN4 package there is no washer that would fit this knob. Is it OK to operate this knob without a washer or are there parts missing?

Could anybody help me, please?