I've devised an uncoupler for Marklin z couplers. Please see the video. -> [ame="http://jp.youtube.com/watch?v=eFhQyVqr8bs"]YouTube - Uncoupling marklin z wagons[/ame] One end of a thin (0.012" thick) plastic slip is glued to a tie and the other end is left free to move. A piece of 0.012" stainless steel wire linked to a small dc solenoid placed under the table pushes up the slip somewhere in the middle. The travel of the wire should be only a bit more of the thickness of the coupler hook. The slip needs some length to acquire springiness to absorb any shock from the wire. I know it makes tracks look unprototypical, but it works reliably when you know where to stop cars to be uncoupled. Cheers!
