If an N scale engine can't be turned upside down and have the mechanism powered, it has a design problem. Among other things, it would have to have a "this end up" instruction on the box to survive being shipped across the globe! I treated my new GS-4 with utmost care before putting it on the track and it had problems after only a minute or two. I only turned mine upside down and tested it (just like in SVRailroader's video) because it had a problem that needed diagnosing, not to torture it. This is a design or assembly issue affecting a small number of units (based on the GS-4's good reputation), not a mishandling issue. Jim
Just to clarify, I never suggested that these needed to always be physically oriented with "this end up" during shipment, nor did I suggest that it couldn't be turned upside down and powered (maybe not the best idea, but it apparently can be done). I did suggest that with this design, upside down / powered / forced slippage against a piece of track, we would expect something like what was observed. Axle one is ungeared, fixed and driven by the side rods. Axle two is ungeared, free floating and driven by the side rods. Axle three is geared, fixed and driven by the gear train. Axle four is ungeared, sprung and driven by the side rods. Given this configuration, I would certainly expect the free floating driver to jump up and down as the side rods cycled up and down (probably not the best treatment of those delicate rods). Am I missing something here?
