# Why U No Stay on Track?!



## bombardiermike (Aug 1, 2012)

My bombardier coaches keep derailing randomly, then they fall off the table and crack open! Why does this happen?! This usually happens with the cab car, and every time the cab car cracks open, my custom pilots come off, and the trucks are twisted in the weirdest position ever! WTF?!


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## gunrunnerjohn (Nov 10, 2010)

First off, please watch the language, this is a family forum.

Obviously, if they're falling off the table, the first thing I'd do is have a low railing or plexiglass shield on the edge of the platform to prevent them from crashing to the floor.

As to the reason for derailing, I'm sure that could be many causes. First step would be a very close physical examination of the car and trucks to see if anything is amiss or binding.


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## Carl (Feb 19, 2012)

After doing what gunrunnerjohn suggests, I would check the weight of the cars. If you weight them using a spring-load scale, load up the weighing platform with enough weight to center the weight indicator in the center of weight scale, then weigh the car. (I say this, because spring-load weight scales are inaccurate for the approx. 30% of the scale on both sides. Electronic scales do not have this problem but they are more expensive.

Suggested car weights can be found on the NMRA web site.

Hope this helps.

Carl


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## gunrunnerjohn (Nov 10, 2010)

Good idea on the weights.


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## bombardiermike (Aug 1, 2012)

Sorry for the language, I was really ticked because I only have one day left to finish this layout before going on vacation. I found that the wheel flanges of the cab car were riding up on the track because of 2 uneven spots, and I made it a little better, but the wheel flanges of the car car still ride up on the turnout so it ends up going the wrong direction. Then the coupling pulls the rest of the train (going the right direction) off the tracks. All this stuff is new from Athearn and all the boxes say "appropriately weighted to ensure smooth operation".


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## zorba (Aug 6, 2012)




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## cv_acr (Oct 28, 2011)

bombardiermike said:


> I found that the wheel flanges of the cab car were riding up on the track because of 2 uneven spots, and I made it a little better, but the wheel flanges of the car car still ride up on the turnout so it ends up going the wrong direction.


Several factors can be involved in a car derailing. The weight of the car. The gauge of the track. The gauge of the wheels. How tightly the truck is screwed to the body (does it wobble, does it turn easily). Any imperfections in the running gear (twisted trucks, crooked/wobbly wheels), any imperfections in the track (bumps, dips, kinks). Even whether the car is being pushed or pulled can exert different forces and a derailment might only happen in one direction.

You mentioned uneven spots in the track - for reliable operation you really need to take care with your track and make sure it's as perfect as possible. Sloppy trackwork will not be tolerated and the result will be derailments. A track imperfection + an equipment imperfection is a surefire recipe for a problem.

Derailment-free operation IS possible, but you can't cut corners on wheels and trackwork.


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## gunrunnerjohn (Nov 10, 2010)

In line with what Chris says, I've run across situations where nothing is apparently wrong, but you have derailments in O-gauge, and I'm sure it's the same with other scales.

O-scale cars with scale wheels (instead of the more normal hi-rail wheels) in O-gauge will derail on Atlas switches. It's just a problem with the design of the switches in relation to the wheels. The smaller flanges catch on the frog and off she goes!

You need to look closely at your switch (turnout) to see exactly what's happening, because you may have a very similar situation. In the case I described above, we hacked one switch frog to change the angle of the point on the frog and it seems to cure it.


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## bombardiermike (Aug 1, 2012)

@zorba XD! Thanks everybody. I keep tracing the problems, and it seems endless. First I noticed that the wheel flanges were riding up, then I found that the track was slightly out of gauge (fixed that), then the wheel flanges were caught on the opposite switch point which I had never even noticed before (fixed), and now it runs fine for the most part. Running the train at medium speed, it doesn't derail, but the wheel flanges catch on the frogs. Running the train a little faster, the cab car derailed completely and fell on its side. The cab car has been the most problematic, I'll try to fix the problem with the frogs and check the cab car for gauge and trucks. Thanks.


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## broox (Apr 13, 2012)

is rhe cab car the first car after the engine?
i've found that due to the way the couplers are mounted on my loco vs the first car (mounted to the body vs mounted to the bogie) a little extra weight is needed on the first car because the rear coupler on the loco wanted to pull the car wide around the bends. forcing a derail on that first cars bogie.

hope it helps.


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## zorba (Aug 6, 2012)

@bombadiermike. good to see someone else on my geekness level


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## bombardiermike (Aug 1, 2012)

I think I got it (or not) The axles on the coaches are multiple pieces, so some of them are a bit tight on gauge (7.5mm between the flanges) so they are catching on the switchpoints still. I adjusted them a bit and now I'm running tests again. I am considering using Peco turnouts in the future, because I looked on other forums and people say that they are higher quality than Atlas ones. Is that true?
Thanks


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## Carl (Feb 19, 2012)

Peco turnouts are very good. I would suggest that you look at the electrical side of the Peco switch and gain a understanding of the various types of switches (there are differences)....I did not do this and ran into a big time electrical wiring problem. The Peco web site is a good place to start.


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## bombardiermike (Aug 1, 2012)

I tried to run it again, same thing. Seriously?! I am in school now and I have less time to waste on turnouts, next time it will be Peco!


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## Carl (Feb 19, 2012)

Have you given consideration to the thought that the car that keeps derailing is truly "the car from hell"?


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## zorba (Aug 6, 2012)

theres a point. try it on someone elses track with a similar track section


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