LGB-style "bottle opener" coupling

thingiverse

I'm replacing the worn-out plastic spring used by LGB to push up the coupling hook. Over time, these springs deteriorate, causing sagging hooks that can lead to wagons spontaneously unhooking from your trains. To fix this issue, I've opted for a spring salvaged from a ballpoint pen attached to the pivot mechanism. The new spring has an outer diameter of 4.5 mm and is carefully cut to length. The hook remains secured to the coupling using a M3 bolt and a washer.