I have a kind of strange, annoying problem with SOME of my DC steam locos stalling as they hit an Atlas 30 degree crossing. The problem seems to only occur with older DC only Manuta Pacific-based locos. By that I mean original 4-6-2's, and other wheel arrangements I kitbashed from that model. It does NOT happen with a 4-8-4 I kitbashed from the Pacifics, nor with any based on the older Mikados, including 2-10-2's and 2-10-4's. Even if the stall does not occur when the drivers roll on the insulated frogs, but when either six-wheel original tender trucks hit the same points I get stalls with the Pacifics, but the very same original rigid trucks with the 4-8-4 does not! I also get stalling when a 2-6-2 based on the Pacific has its 4-wheel tender trucks hit. Other locos with 4-wheel tenders, even sprung trucks with axle wipers do it.
Pretty aggrevating and I have tried checking for continuity, etc. with a multi-meter, and still haven't a clue. The offending locos don't stall on the frog of Atlas Custom Mark IV frogs, which are longer. Aside from trying to find a 30 degree crossing by another maker, I can't figure it out.