A newbie's derailing problem - need help, please!

[New to N]

At the tender age of 65+ I'm brand new to the hobby and to N scale. Started with the basic Super Chief set and everything worked fine running the train in the 24" circle, even at top speed. After buying additional track (Bachmann 44811 & 44801) I laid out the "dogbone" as shown on the back of the package. When running the basic  loco + 3 cars at anything other than a very slow speed (the mark on the controller at about the 2 o'clock position) the front truck on the engine derails at each of the four "major" curves. This happens about 95% of the time. The rerailer often, but not always, helps reset the trucks but at the next major curve it jumps off again. While I don't know much, I can say that the track is laid out correctly and every track piece joint is firmly seated including the rail joiners. Also the track is flat on a smooth work bench but is not fastened to it and there are no high spots on the rails, etc . I'm beginning to wonder if the engine is defective. Any suggestion as to how to make this fun instead of frustrating? Any and all suggestions will be appreciated!

[Joe Satnik]

What happens if you run the diesel locomotive alone?

Joe

[Country Joe]

Your derailment problems may be because you have an S curve. This occurs when you have a curve in one direction, say a left curve and go into a right curve without enough straight track between them. S curves are notorious for causing derailments. I don't know exactly how you have the track set up, but this is my best guess based on your description.

[Mike C]

 It,s very possible that the wheels are out of gauge on the loco. They may be just a hair too wide. You would need an N scale NMRA wheel and track gauge to check this though. Will it run OK through the curves by itself, or in reverse ?

[New to N]

Thanks to all three of you who are helping. I really appreciate it! To answer all your questions. Even with the loco alone it derails when running forward, sometimes even jumping when going thru the rerailer, and that isn't at top speed.  It runs perfectly in reverse even at the controller's top speed. It also runs perfectly, in reverse, with the three cars attached. I don't think curves are too tight as the layout is the one that Bachmann illustrates on the back of the kit box. What's next, guys?

[Mike C]

 No,I believe you're curves are fine too. Pretty sure it has something to do with the front truck of the loco. Can you move the truck assembly freely left to right and tilt it easy up and down ? It should move freely in all directions. Can you compare the wheels with the wheels on one of the cars ? Look to see if one of the wheels is a bit wider than the others.

[New to N]

Mike, the wheel trucks move freely in all directions. No binding. I used a caliper and measured as best I can and found this:  loco wheels, outside to outside (not flange to flange) all 11.8mm. The wheels on two cars measured 11.9mm. Since this is such a tiny thing to measure, and the caliper is a rather inexpensive one, and 1/10mm is really miniscule, I wouldn't stake my life on the numbers! Eyeballing they all look the same. Can the loco wheels be moved in or out a bit on their axles with careful finger pressure or is there another way to do it. If I were "backwards" I would love this train, it runs like a champ in reverse at top speed and never jumps the tracks! Thanks again for your help. If anyone else has some suggestions, please let me have 'em.

[jonathan]

New,

The locomotive in the Superchief set is an F unit.  The nose portion hangs very low, in fact, barely above the rails.  It is very possible the lower portion of the nose is rubbing the rails on a curve, just enough to cause the front truck to jump the tracks.  Perhaps filing a nanometer off the bottom of the nose will do the trick.

Since the locomotive doesn't jump in reverse... This leads me to believe something is catching the rails in the very front of the locomotive.  The locomotive is not designed to "cant" when on a curve, however, it could be doing it anyway, just enough to catch a rail.  Just a thought.

Regards,

Jonathan

[Albert in N]

I can relate since I am age 69 and still enjoy running my N scale trains on a simple layout.  I have enjoyed model railroading since age 7, in various scales.  On a whim, I bought a Bachmann Highballer set at Hobby Lobby several years ago.  The dog bone layout on the back of the box also impressed me.  Thus, I added a dog bone on a portion of my modest layout.  My Bachmann F-9, Spectrum F-7 AB set, Kato F-3s and F-7s, as well as my Intermountain F-7 have no problems with it.  My layout now uses only Kato Unitrack, but the inside dog bone portion is the same 11 inch radius curves like those from your Bachmann set.  If you have not already done so, try running your locomotive in the opposite direction (switch the locomotive and caboose ends).  Then, try to find the exact place where the locomotive derails.  Remove that portion of track and mark it (one way would be to put tape on the underside).  Trade out that section of track with track from the no-problem track from another portion of the layout.   From my experience with Bachmann E-Z track, I have found defective sections with excess plastic flashing, rails bent up (lay track section face down on a hard surface to see if level) as well as bent rail joiners.  Maybe filing or trimming, or replacing, a few bad track sections will fix the problem.  Before you try filing or "fixing" your F-7, you could run a Bachmann GP-40 diesel (or other brand locomotive) around your layout to see if loco clearance is an issue.  Good luck!

[New to N]

Problem Solved - thanks to 5 guys who helped! Each of you had a piece of the puzzle and it's now solved!Due to my rank inexperience I tried the easiest suggestions and they were successful. I swapped out track at the joints where the loco jumped. I looked at the underside of the front of the engine and saw black rub marks. Some sanding with crocus cloth and trial and error took care of that.  I have run the train 15 times around the dog bone at top speed without any derailing at any of the 5 curves, so I declare the crisis "over." Thanks again, guys!!  For possible future need can the front and rear loco trucks be swapped without too much surgery? I still believe that the front truck's wheels are a bit too wide as even before the sanding and track exchanges the loco both pulled and pushed the cars like a champ when reversed and ran through the rerailer in reverse without a hitch. Do hobby shops stock track gauges or are they available on the web?
Thanks again - my cap's off to you.

[Albert in N]

New, glad to hear the problem was solved.  On the earlier Bachmann F-9 train set loco, the coupler length is the same, so the geared wheel sets can be easily swapped.  Just loosen the split frame until the geared wheel sets come loose, then tighten back after the swap.  I am not sure that your newer F-7 set loco has the same coupler length, but probably the same as the F-9.  The older Spectrum F-7s are a different design, though your Bachmann F-7 appears to have the same shell as the Spectrum.  I see your Super Chief set at the local Hobby Lobby and it looks like fun.  It has the dummy knuckle couplers, but is OK unless you want to do switching out cars (need magnetic couplers and track magnet sections for that).  On the Hobby shop issue, most have more stuff in HO and not much in N.  You could ask about an N standards gauge, but you will probably have to order one.  I suspect that joining the NMRA (National Model Railroading Association) and ordering one from them might be an option.  I do not have an N standards gauge and simply use eyeball comparison with other track or wheels.  A caliper would also work.

[New to N]

Thanks again, Albert. You know your stuff.