Help with lionel Hogwarts express o gauge set

We recently bought a Hogwarts o gauge set and basically the train keeps coming uncoupled. The set up is a standard 40 by 60 oval. I am not sure why this train keeps coming uncoupled. It is on a flat surface. Any suggestions would be appreciated

Welcome to the forum.

Which car(s) is/are having the problem ? If this is a new set and you bought it from a local shop I would contact them first. If you just want a quick cure for knuckle couplers opening between coaches this can be remedied easily by the use of a rubberband. When available I use the orthodontic type otherwise I buy the little black ones in the hair care aisle at the grocery. Normally there are three or four different sizes, the smaller ones just go right on but the larger ones generally require two loops . Just place it around the shank of the coupler so it provides some addional support the the uncoupling tab/arm.

Have fun and enjoy the hobby.

I had exactly the same problem with my Hogwarts set. Turns out there was one passenger car with one coupler with a very weak spring. I put in at the end of the train with the bad coupler facing to the rear-problem solved. The trucks on these are not the best I’ve ever seen-I’m sure a train store with a service department (i.e, with a rivet press) could replace them with units of a much higher quality. They’d probably be sprung trucks, too.

I just bought one myself, but haven’t really had a chance to run it much because I’m waiting for more track.

I am curious about this because I just started haveing the same problem with my Polar Express after 4 years. It happened once before on one of the cars and I found the spring leaver that holds the coupler in place had somehow moved out of its position so I moved it back into its grove and that was the end of that. This time around I’m thinking it might need some oil.[:)]