Peco Insulfrog Nscale Turnout & Derailments

[Herc Driver]

Very good question, and yes, I've checked and rechecked the gauge of the wheels and everything is spaced correctly.

I noticed this problem quite a while ago, but haven't written about it looking to see if my problem was also seen by others. I think the Peco turnouts are great, but I've seen this problem since I installed them but only on one car or two. As I continued to add engines and cars to my collection, more and more would show the same trouble crossing over the frogs. My gut feeling is the depth of the frog is too shallow which allows the wheel flange to ride up and mis-align the wheels to derail. I notice this problem more with three-axle engines and cars. Additionally, I've seen several fuel tanks on engines ride up and atop the plastic guard rails (sometimes called the frog I believe). I'm going to try to file the guard rails down slightly and try to deepen the channel that makes up the frog point so the wheels can roll through without an elevation change.

I know there's lots of people who use Peco turnouts, so I'm concerned others have not seen this issue. Makes me wonder if the cause is something I did when placing the turnouts on the layout. But honestly, I don't see that as a possibility since all the turnouts (except one) have straight track going to and from the turnout, and all are on level foam board. And I checked each turnout and they're not flexed or twisted, or under any pressure from the adjoining rails.

The only other possibility I can think of is, since I run engines and cars from various manufacturers, there's any number of different wheel dimensions traversing the turnout. Some with longer flanges than other I would suppose. Microtrains have the Standard and Low Profile wheels, InterMountain has the 33" and 36" wheels, and I'd guess there's subtle differences between Athearn and Atlas wheels sets as well. I've noticed that Athearn and Atlas cars almost never derail, while InterMountain and Microtrains wheels sets on longer cars like auto racks or passenger cars are prone to when crossing thru the turnouts (not always, but about 25% of the time). Additionally, I've noticed Atlas, Athearn, Kato, Bachmann, and LifeLike engines almost never derail. But I've got to watch the PCM, InterMountain, and Fox Valley engines as they go through the turnouts. I will try to take one of the cars that derail often and replace the wheels with a low-flange type, just to see if that makes a difference. I've also read that switching every wheel set to metal wheels makes a difference as well. I'd guess 80% of my rolling stock has plastic wheels. So I wonder if converting them to metal wheel sets would improve the running ability? I know there are some that swear by all-metal wheels to improve running ability and track cleanliness, while others say that's not necessary.

Thanks guys for reading through all this and offering some ideas. I certainly appreciate it.