Hi BlueComet! Have you found any answers? I have a prewar American Flyer steamer #447. A 2 6 4 that has become my baby. The drivers are big & the flanges deep which has prompted the same questions from me. I've picked up some K Line shadow rail 072 switches to try that my loco seems to slide thru pretty easy.
Hi Balidas,
After much trial and error, I finally settled on the O-Line Reproductions (formerly RMT, before that K-Line Super-Snap) O72 switches. It was a long process, starting with RMT, sending them back due to shorts, then Fastrack, sending them back as well as they did not play well with my tinplate locos, then back to the O-Line switches after finding a cure for the shorting issue shown below. Everything I have--prewar, modern and everything in between--rolls right through them, with the exception of my Marx trains with the large gears, but that's to be expected. Like any switches, there are a few quirks that I've discovered:
1: All the right-hand switches have a design flaw that causes anything with a pickup roller to short/spark as it rolls through. This is due to the fact that there is no air gap between the curved lead and the frog. If you look at the straight lead and both leads on the LH switches, you'll see the small air space between the leads and the metal frog. Thanks to other posters on this forum, the problem is cured by a strip of tape over the length of the curved lead.
2: Some of the wiring is a bit fragile, but with a little bit of soldering, you can improve it. In the photo below, you'll see how I soldered a short jumper wire between the 2 center rails as this can be a very weak connection on some of the switches. It's a relatively easy fix that improves electrical connectivity through the switch.
3: All of my smaller pre-war locos with 4 drivers (249e, 263e etc.) won't go through the switch without hitting a "dead spot" due to pickup roller spacing, and as a result, activating the E-Unit. Thanks to GunrunnerJohn, an easy fix is to create a tether between the loco and tender, connecting one end to the E-Unit on the loco and the other to the pickup roller on the tender, effectively giving the loco one more pickup roller to the center rail. Larger engines with 6 drivers don't have this problem as the distance between pickup rollers is longer.
John