>> I ask because it would be interesting to know if QC issues have always been a part of this hobby.
>> Sunrise
My experiences have been that American-made toy trains have generally been more free of defects than foreign-made toy trains. The key word here is "generally" because there are numerous exceptions to that general statement.
As a Lionel 3-rail O gauge youngster, I do not ever recall having any performance problems with any Lionel product ever. As a teenager, who switched to HO for greater realism, there were numerous problems with HO kits where the parts did not fit together properly. The RTR products, as I recall, seemed to generally work OK.
After switching to S scale, most of the QC-related problems I have personally experienced were with Korean-made brass imports. I do not recall ever having a problem with mass-produced plastic products from American Models or S-Helper Service. But the hand-made exquisitely-looking brass imports were loaded with problems. Lots of problems over the years and they still have them to this day.
My real peeve with the brass imported models is that the same problems occur over and over again on different models. There seems to be little effort to learn from the past and use that knowledge for an improved future. One example: Pressing plastic parts onto metal parts. This is commonly done with plastic gears, u-joints, wheels, etc. which are pressed onto axles and shafts. With time, the plastic outgasses, becomes old, becomes brittle, shrinks, and -- eventually -- splits. When the gear or u-joint splits, it then slips on the metal shaft and becomes useless. I cannot tell you how many times this has happened on brass imports from Korea -- enough times to convince me nobody really cares. (NOTE: This is not a Lionel problem as far as I know.) And, to make things worse, it has an easy cure: splines on the shaft, flat on the shaft and flat spot on the plastic part, Delrin plastic parts (stronger), set screws, etc. Take your choice of solutions -- there are several.
One brass model I purchased would not run around a curve -- any curve. The problem was that the tender trucks were attached to the tender floor BEFORE the paint was fully cured. When the paint cured, the trucks were firmly attached to the floor and would not swivel. The QC issues with brass imports go on and on and on. One reason for this is the extensive hand efforts that go into each model. Thus, precise repeatability is difficult when compared to injection molded and die cast parts which are exactly the same each time.
To answer the original question: I think QC issues have always been a part of the hobby, but some firms (Maerklin, Fleischman, LGB, Zimo, etc.) have very good reputations for quality. QC problems, whether design-caused or production-caused, are preventable with good inspection. Many, if not all, of the European firms have resident inspectors in the various Asian factories to personally inspect and approve products before they leave the premises. These inspectors are on the payroll of the customer and live (temporarily) near the factory and spend their working hours in the factory dealing with QC matters.
Of course, excellent quality does not come with a cheap price. I once spoke with a German inspector resident in Korea (years ago). He opined that, in general, the American market was not willing to pay the price for excellent quality whereas the European market was happy to do so. Thus, European toy trains were more expensive and of better quality when compared to their typical American counterparts.
Being an O gauge kid, I have no experiences with Gilbert AF. Being an S scaler as an adult, I have not had any experiences with Lionel/AF products in the recent past. I am now the happy owner of two L/AF SD70 diesels, but am very much aware of the potential for problems because of the complexity of today's products compared to the so-called good old days.
The electronics of today are a far cry from that of the 1950s. So are the motors and drive trains and couplers a lot more complex these days. All of this new complexity makes it much more difficult to build a product that will last for 50 years while needing only a drop of oil from time to time. Yet, in spite of that, I would not want to trade the L/AF SD70s for a Gilbert ALCO PA. Totally different animals for sure. One is an adult toy and the other is wonderful for kids.
Random thoughts on a Sunday afternoon.
Cheers....Ed Loizeaux