"I switch the frog's polarity using contacts on the point motor instead."
Which is fine, of course, if one is using point motors or not just testing layouts...
What about if it is a manual switch?
I have lots of non-motorised Peco turnouts on my layout and developed a modification to switch the frog polarity. Here are some pics...sorry for the poor quality.[img]http://i33.photobucket.com/albums/d89/roachie01/DSC05556_zpscba4e1dd.jpg[/img][img]http://i33.photobucket.com/albums/d89/roachie01/DSC05555_zps40484792.jpg[/img][img]http://i33.photobucket.com/albums/d89/roachie01/DSC05553_zps4d91c72b.jpg[/img][img]http://i33.photobucket.com/albums/d89/roachie01/DSC05552_zpsa49dae44.jpg[/img][img]http://i33.photobucket.com/albums/d89/roachie01/DSC05551_zps82f82b9a.jpg[/img]
Like I said the quality is poor, but basically it involves using a small SPDT slide switch. There is a 0.95mm hole drilled through the actuating "arm" of the switch and a piece of 1mm brass wire is forced through....this wire extends up through the hole in the throw bar and is snipped off later flush with the top of that bar. The throw distance of the slide switch is almost exactly the same as the Peco throw.
These switches are available on ebay for a very cheap price (something like $10- for 50 of them as I recall).
The switch is not glued to the base of the turnout, but is held in situ by the 3 wires. The 2 outer tabs of the switch have a piece of solid copper wire (stripped from a section of household mains wire). These 2 pieces of wire, once soldered to their respective switch tabs, are routed through the gap between the underside of the rail and the top of the sleeper, then bent at 90 degrees and soldered to the outside of the rail.
The central tab of the switch also has a strip of that copper wire attached and it goes right down to the frog, where it is soldered to the piece of wire that Peco provides on the underside. I try to route the copper wire along under one of the rails so it is not so obvious and once it is all in place, I carefully apply heat to the copper wire whilst using a flat balded screwdriver to progressively press the wire into the "melting" underside of the sleepers. This ensures that the turnout still sits flush with the road bed.
Of course a suitable hole needs to be drilled in the baseboard/road bed, to allow the switch to fit in.
Also, the 2 small pieces of wire that Peco have installed to join the closure rails to the frog need to be broken away (with needle nose pliers or levered with a small screwdriver).
It may sound complicated, but is relatively simple to do.