This is one of my areas of particualr interests. Unfortunately, narrowing the gauge on most commercial turnouts requires major surgery. It's probably easier to yank out the worst offenders and hand lay new ones in their place. A few things one can do with commercial turnouts:
- Check the guard rails carefully. Often they are set too close to the frog (Atlas often has this problem). This lets wheels "pick" the frog. Put a strip of thin styrene on the side of the guardrail close to the stock rail.
- Make sure the tops of rails are level all the way across the stock rails, guard rails, wing rails, and frogs. Any dips or bumps need to be fixed. Sometimes, frogs are higher than the surrounding rails (Atlas again is a common culprit). Applying a soldering iron to the metal frog and pushing it down slightly as the plastic base softens sometimes works.
- sharpen the end of the points and chamfer the end where it sits against the stock rail. This helps prevent "picking the points".
A caution to narrowing the gauge - the narrower the gauge (which also narrow the flangeways at the frog), the bigger the minimum radius required by the rolling stock.
Although I don't believe the NMRA did this by design, the slop caused by the difference between the wheel gauge and track gauge does allow our models to squeeze through much tighter turns than they could otherwise. If you narrow the track gauge to NMRA minimum (there are expert advocates for even narrower), the LDSIG rule of thumb becomes the practical minimum radius standard. Longer truck wheel bases will bind going through curved narrow flangeways and/or sharp curves when track is gauged at or less than minimum.
The LDSIG rule of thumb states that minimum radius is 3 times the length of the car over the couplers for good operation with body-mounted couplers (appearance not considered). In HO, this means the 18" radius is only good for 40ft or smaller cars and locomotives. The 22" radius will pass perhaps 55ft cars and locomotives. Full size passenger cars with 6 wheel trucks should have at least 36" radius curves.
P87 runs into the same minimum radius issues. When you take the slop out of the track, you increase the minimum radius requirement to a more realistic value. The payoff is in much improved appearance, and derailment- and rattle-free tracking though turnouts.
Final tip is to match the wheel profiles and back-to-back to track standards. In HO, code 110 wheels are designed to be used with NMRA spec track and turnouts. Code 88 wheels (often sold as "fine scale") look much better, but tend to rattle a little going through NMRA spec turnouts. Code 64 wheels (prototype width) will not run on NMRA spec. Track needs to be laid to P87 spec, where it will work very well. Track and wheels are an integral system that need to be matched to each other.
There is lots more on this topic in the archives of the Yahoo Handlaid Track Group (
handlaidtrack : Hand Laid Track)
my thoughts, your choices