Had to move bones

After seeing my original bones were not working right I have lined the bones up slightly offset to the second arm to keep the rotate alignment aligned with the stem.
In this image you can see the second arm bone is to the right, to keep a clean rotate on the hinge.

Still wasn’t rotating right, so have redesigned the bones yet again, seems to work now.

I have come back a few lectures as I had to redesign the lamp, make sure your lamp rotates through the middle and doesn’t offset, otherwise you get bone problems where the arms rotate about the bones in an offset manner.

Ive redone the lamp so that the hinges and arms all run through the centre. I added a hinge at the bottom as well.