Good day. I was wondering what the extent of resistance/voltage drop occurs over junctions that are made off movable parts and brushes. Electrical trains tend to get the voltage from brushes so it can't be too great, also brushed motors. In my case I was planning to run an electric brushless motor, but it is situated on a moving part, so either it was making long wires that can bend and twist a little, but that takes some space which would make my mechatronic machine larger. But then ofcourse I figured a simple coal brush or whatever like they use in brushed motors, and since this moving part will be moving far less, slower then in a brushed motor, it should last, my only concern left was weather there was a great amount of power loss in the junction between the brush and the moving part. I made a quick sketch of the concept, the moving part moves +/- 30 deg, around an axis.