I was so worried about destroying the wire connections on my K-27 that I designed and built a carrying case that allowed me to keep the engine and tender joined all the time. I cut grooves in the underside of the case so it fits onto a couple of feet of straight track, and I push the engine down a short ramp (double-grooved top and bottom) right onto the track. The upper part of the case splits open like a clamshell, so I can put the whole thing on the dining room table and open it up in order to worship it.