In Conjunction with Radii

[trainnut57]

While reading a thread regarding what locomotives will successfully negotiate an 18" radius, I recalled a problem I have been wrestling with for two years. I bought two Northern type locomotives on line from a reputable dealer, that's not the problem. The problem is: Both are Bachmann (Silver Series); one is a GS-4 and the other is a Niagara. The GS-4 runs well and curves fine. The Niagara runs well and will not take a curve, banked or flat, without the front pilots leaving the track. It's not the particular curve nor the radius, my minimum radius is 22", it has to be the front trucks. I have checked for gauge-OK. I have added weights to the pilots-NO LUCK. I have greased the axels and where they connect to the truck mount, NADA. I have greased (LaBelle grease) the slide bracket where the pilot truch is attached to the body-NOPE. And it derails anywhere it wants to-curve, straight-away, turnout, even on a re-railer (I have two on my layout). I have contacted Bachmann about the problem three times but only received one answer back which didn't help at all-they suggested I interchange pilots with the GS-4 but they should have known this was impossible-they are two totally different pilot trucks. I'm at my wits end here hobbyists, I really need some REAL professional help, so I am turning to the best-YOU. These locos were not cheap, nor were they overly expensive, but fit well into my layout scheme-except the Niagara is static. HELP!!!!!!!!!!!

please excuse the long winded explanation, but I felt it was necessary-I need new ideas not re-hashes of old ones. If Model Railroader is monitoiring this topic, FEEL FREE TO CONTRIBUTE, I need all the help I can get on this one. I have been in the hobby over 25 years abd have never encountered this type of problem.

Thanks in advance.

[Leon Silverman]

Try spinning the wheels on the truck to see if they rotate true (no wobble). I had a problem with the wheels on an Athearn DD40 dummy engine that mysteriously derailed on smoothe track (all joints soldered together and filed smoothe). The problem was eliminated when I replaced the wheels with one from another dummy Athearn engine. Sometimes the wheels are not exactly centered on the axles. This eccentricity can sometimes be severe enough tocause derailments on curves.

[ndbprr]

I had the same problem on a PRR P5a finally figured out there wasn't enough lateral movement to the pilot truck. Check the clearance while holding the engine upside down and see if there is any way to allow the pilot truck to move sideways more. In my case the pilot truck had a slot so I widened it. no more problems. In other cases something may interfere with the movement.

[trainnut57]

Now we're getting somewhere. ndbprr's suggestion is one I never thought of. Thanks. I'll give it a try aa soon as possible. It's very cold here in NWPA and my basement is only 50 degrees right now, so working there is a limited option this weekend.

As for Leon's suggestion, that was one of the first things I considered and tried, and I even thought about replacing the wheels. I cannot detect any wobble or anything, but just maybe replacement might work-you cna't always see minor defects.

These are two great ideas and I thank you guys for your interest. I will keep checking this thread for any more help.

[mcouvillion]

trainnut57,

I have had some of your problems before, and tried the same stuff as you. I think your best bet is to replace the wheels and axles of the pilot truck to a better quality product. With metal wheels and RP25 contours, the added weight and better profile should help these to track better. You might also replace the tension spring on the pilot truck to something a little stiffer (not too much, though, or it will lift the front driver off the rail!).

As far as working in the cold basement, get a small piece of cardboard and use it on the kitchen table (or a coffee table) where it is warm. No need to freeze to run or work on your trains. You only need to bring the minimal tools you will need for the job at hand, and you'll have to pick up the mess before supper or you'll catch it from the boss. (Now I've done it - gotten his railroading out of the basement and into the living quarters. You don't know me.) Best of luck on solving the problem.

Mark C.

[Don Gibson]

SIMPLE

Remove the pilot trucks, If the engine now runs 'normallyi' you know where the problem. is - confirmed.
Examine the pilot truck assembly, closely See where the problem can be?.
gage?
malformed flange?
insufficient range of motion?
binding?

WORST CASE replace pilot truck
WORSER CASE it's not the pilot truck.

[dinwitty]

watch the wheels carefully first as they traverse your curve.

find out where the derailment starts and watch the pilot trucks.

you may try lubing all the surfaces the truck has.

check gauge.

you really need as flat of trackwork for these locos.

sometimes you could spike in inside guard rails for the curves to help lead wheels into the curve. and even have the inner guard rail be on the whole curve.