A couple weeks ago I was talking with a guy running his recently acquired (secondhand) large-scale plastic train on an oval of track at a train show. He was having derailment problems. On closer inspection I could see that the loco drivers were working loose on the axles and flopping around, the lead drivers in particular.
I recalled that I had worked on a similar locomotive about three years previous, and it had the same problem. At the time a friend was repairing trains for a local hobby shop and when he got busy around Christmas time, he drafted me to help out. I had taken the loco apart, re-gauged and reattached the loose drive wheels and rods, and it test-ran OK on some straight track.
A few days later the guy brought it back with the same problem. He had bought it used from a second-hand shop. Said his young daughter loved the big train and they really wanted it running for Christmas. Told him I needed an oval of track to properly test it but he said his track was all nailed down at home, way out of town. I managed to borrow some track.
I fixed the engine again, this time with super-glue to help keep the drive wheels from working loose on the axles. When I test-ran it on an oval circuit (of standard radius) I could see that the long wheelbase of the drivers was really pushing the limit for that curvature. Essentially a poor design with cheap materials.
Those big plastic trains are designed to be relatively affordable, but if durability is lacking it's certainly going to discourage a newcomer in the hobby. And if they are too expensive in the first place, that too will keep newcomers from getting involved in the hobby.
The moral of this story is, don't run long-wheelbase steam locos with plastic axles on sharp curves.
The locos in question were similar to this, Brand "B" I think.
here
