Derailing problem.

[Anonymous]

I have a unique problem, whereby only one of my locomotives gets derailed in exactly the same spot regualrly.

Both the spot and the loco ar unique in that it is a curve of about 220 degrees and the loco is an LGB Stainze running in conjunction with a powered LGB tender under MTS control. It only does it when running in a clockwise direction never the other way!

1/ I have really looked at the camber and this has helped a lot, the track now is a perfectly laid as I can get it.

2/ the Stainz had it driving rods out of phase and not working properly I got this right which also helped.

3/ As you know you have a special connection bwteen the loco and th tender and this was sticking to one side, this is now ok but I have had one derailment after about three hours of running. It seems to be a bit worse when the temperature get sover 35 deg and the humidity over 90 %.

Does anyone have any ideas?


Rgds Ian

PS This is what i regard as a reasonable subject about actually running a garden railway; a problem has occured and people with experience may be able to comment! Or even those with little or no experience can ask questions and learn something about this hobby.

[Anonymous]

If it gets worse when hot it could be an expansion problem.Do you have expansion joints on the layout.If you've soldered the whole thing together without allowing for this,things could buckle just enough to derail perhaps.

[tangerine-jack]

What kind of track are you running? I agree with Troy, it sounds like an expansion-tension problem, but it's interesting it only happens unique to one loco/direction. If your track is handlaid there (and I believe you make your own track) then the rail may be trying to uncurve itself at that point, causing a twist or out of guage condition.

Have you checked the guage of each axle set of the Stainz? One set out of guage would cause such a problem - the loco parts also expand and contract with temperature. Are all the wheels actualy round?? Check them anyway! Do they all roll in nice circles are is any of them off center (or centre for you UK types) or eliptical?

You've already logicaly checked possibilities, so we must now use a different line of thinking to solve this problem than we used to create the problem in the first place. I had a similar problem at one switch (point/turnout/shunt) and I replaced that section of track, and put new wheels on the loco, and the problem went away. I never did figure out if it was the track or loco, but I believe it was a combination of both just being incompatable in some wierd cosmic way.

Good luck!


[oX)]

[Anonymous]

Thanks mate, we are actually having a reasonable discussion about a subject to do with Garden Railways, which is a pleasant change.

I do not think it is a track problem as it doesnt happen with any of my oither locos and i have 7 of them now. I think it only happens at this spot as we have a slight down hill run and we have such a tough curve, I was wrong about 220 deg, it should be 120 deg. It is LGB track by the way in this instance. The track in this spot is virtually perfect.

I am convinced it is the unique combination of s small Stainz loco and a powered tender that is the problem, more importantlt the unique way this must be coupled as the tender at different times is pulled and drives.

After quite a bit of observation and experimentation I am pretty certain that the coupling is the problem! When all else fails use WD 40 which will fix the common cold. it has been freed right up and it seems to be going ok now.

I would like to know if anyone else has one of these combinations and if they have had trouble with it.


Rgds Ian

[tangerine-jack]

What is so unique about the coupling? I missed that part. It does sound like the problem is isolated to that one loco. A binding coupling certainly would cause such a condition as yours. Have you tried some graphite grease instead of WD-40? Graphite is usualy longer lasting and more resistant to the weather.



[oX)]

[piercedan]

The LGB tender has a set of switches inside to control the start delay/speed of the tender. This is used to try and mtch the tender speed to an engine.

If the speeds are different, you could get derailments in one direction.

Separate the engine and tender and run them to see the speed difference, hopefully there is little or none.

[Anonymous]

Yes men you are making sense; the coupling is unique to do with having a powered tender. The loco has what looks like a tongue type of hook that is a right angle pointing down. The tender has an arced slot going from one side to the other. The tongue rotates on the back of the loco as it goes round bends and the down part of the tomgue slides fron one side of the slot to the other as it goes around corners.

I am not sure if the delay switch mentioned works while it is part of an MTS set up.

However by really freeing up the tongue or swinging arm it has helped a lot.

I hope Troy is reading this or someone familiar with MTS as I think it may be an MTS problem as well. As standard on MTS, when you first get one of these tenders you must match up the speed of the tender with the speed of the loco by running them separately and they should maintain the distance between them. Which i did do, I am not sure what speed i run them at but they were near perfect. However i now have a policy of running them at speed 8 on MTS, and at speed 8 I have suddenly forund that the tender is catching up to the loco steadily.

I think that this being the case the tender may well pu***he Stainz off the track when going down hill on a bend.

How does this sound to you guys.

Rgds Ian

[tangerine-jack]

Logical, Ian. I have always had an inherent psychological problem with the idea of two powered units pulling a model train. I never had much luck with it in HO because of manufacture variance sooner or later one unit would either push or pull the other, with neither one gaining any additional pulling power. This was even with two brand new units, same stock number and everything. The real railroads use computers for this action, and even then they still have issues.

This may be happening with the Stainz, and with MTS control who knows? Gravity may play a part in this as well, the tender may be frewheeling down the incline just fast enough to pu***he loco off the track. Have you noticed the derailment happening at a certain speed? Maybe you just need a posted speed limit on that section of track for that type of equipment, after all, it would add a bit of realism to your operation and be perfectly prototypical for grade operations.

In summation I believe you have 3 problems:
1: a mechanical coupler problem which you are well on your way to solving
2: an MTS- tender/loco speed distortion at 8 or higher.
3: Old fashioned gravity.

The first one is the only problem I know how to easily solve, and we already went over that. I don't know enough about electronics to say what you can do about an MTS compatability issue, maybe a resistor or something can be added to control this problem. Gravity is a physical law, observe the speed limit or the Railroad Police will write you a summons!

Let us know what you find out!


[oX)]

[RhB_HJ]

QUOTE: Originally posted by iandor

Yes men you are making sense; the coupling is unique to do with having a powered tender. The loco has what looks like a tongue type of hook that is a right angle pointing down. The tender has an arced slot going from one side to the other. The tongue rotates on the back of the loco as it goes round bends and the down part of the tomgue slides fron one side of the slot to the other as it goes around corners.

I am not sure if the delay switch mentioned works while it is part of an MTS set up.

However by really freeing up the tongue or swinging arm it has helped a lot.

I hope Troy is reading this or someone familiar with MTS as I think it may be an MTS problem as well. As standard on MTS, when you first get one of these tenders you must match up the speed of the tender with the speed of the loco by running them separately and they should maintain the distance between them. Which i did do, I am not sure what speed i run them at but they were near perfect. However i now have a policy of running them at speed 8 on MTS, and at speed 8 I have suddenly forund that the tender is catching up to the loco steadily.

I think that this being the case the tender may well pu***he Stainz off the track when going down hill on a bend.

How does this sound to you guys.

Rgds Ian

Apart from matching the speed and going on the assumption that you have the same type of decoder in both engine and tender, I'd check the Back-EMF settings.

[ttrigg]

Sure sounds like a "push/pull" problem to me. Have you ran this configuration at slower/faster speeds for an extended length of time to see if the problem disappears. I have NEVER had any luck running two powered units on any scale. I spent several thousand dollars (US) trying to do just that in N scale one year. I have vowed that I'll never again attempt that feat. If you should find the solution, please share the results. If you are successful, it just might provoke me into trying again.

[RhB_HJ]

QUOTE: Originally posted by ttrigg

Sure sounds like a "push/pull" problem to me. Have you ran this configuration at slower/faster speeds for an extended length of time to see if the problem disappears. I have NEVER had any luck running two powered units on any scale. I spent several thousand dollars (US) trying to do just that in N scale one year. I have vowed that I'll never again attempt that feat. If you should find the solution, please share the results. If you are successful, it just might provoke me into trying again.

Tom,

The trick is the same as they use on the prototype: keep things stretched! That means the tender has to be just a tad slower than the engine.

[ttrigg]

I understand the physics of the problem, what I encountered was that the two units never did share the same power/speed graph slope. For Example: at a power setting of three unit 1 ran at 50 feet per minute, unit 2 rant at 49.5 feet per minute. However at power setting 4 their speeds reversed, unit 1 at 60 feet per minute and unit 2 at 62 feet per minute. Then at power setting 5 unit 1 would do 70 fpm and unit 2 would do 65 fpm. I never could get a uniform speed/power graph going. Thus as I ran through the spectrum of power range, I would get the "push me/pull me" fight going and it always happened when the trains would run along the edge of the layout with the floor five feet below!!!!!!!!!! Lost more units than I care to count like that!

[RhB_HJ]

QUOTE: Originally posted by ttrigg

I understand the physics of the problem, what I encountered was that the two units never did share the same power/speed graph slope. For Example: at a power setting of three unit 1 ran at 50 feet per minute, unit 2 rant at 49.5 feet per minute. However at power setting 4 their speeds reversed, unit 1 at 60 feet per minute and unit 2 at 62 feet per minute. Then at power setting 5 unit 1 would do 70 fpm and unit 2 would do 65 fpm. I never could get a uniform speed/power graph going. Thus as I ran through the spectrum of power range, I would get the "push me/pull me" fight going and it always happened when the trains would run along the edge of the layout with the floor five feet below!!!!!!!!!! Lost more units than I care to count like that!

Tom

Did you do all this with DCC??

Some of the high-end decoder/control combos let you fine tune performance curves to the nth degree or 'til you see stars. Whichever comes first.

[piercedan]

I have track power and run 2 engines all the time.

I have 2 MTS porters paired, 2 sd-45's and 2 LGB cow engines, plus 2 sets of LGB engine/tender combinations.

These do not give me any problems and run for hours on my RR.

The key here is the units that are matched have power cables between them and the speeds are almost identical at slow, medium and fast running.

[tangerine-jack]

QUOTE: Originally posted by piercedan

I have track power and run 2 engines all the time.

I have 2 MTS porters paired, 2 sd-45's and 2 LGB cow engines, plus 2 sets of LGB engine/tender combinations.

These do not give me any problems and run for hours on my RR.

The key here is the units that are matched have power cables between them and the speeds are almost identical at slow, medium and fast running.

You must be the exception to the rule! I have failed to get any manner of lash-up to run to my satisfaction. In Ian's case, I believe it's a problem with the grade and the curve at the end of it. I'm sure on level track a lash-up will give no problems, but running downhill? What is the mechanical resistance of the motors/gearing in each powered unit during a freewheel? I don't know. I might have to fly to Australia and experiment on Ian's RR[;)]

I think Ian will have to decide if it's his power units, coupling, or gravity/grade issue. Perhaps superelevating the curve 8-10 mm would relieve this problem. A simple shim under the outside portion of the curve would do.


[oX)]

[Capt Bob Johnson]

TJ, you're forgetting the other engine that jumps when going the other way! I think the first idea was more likely. tension distortion of trackage!

Oops, that was somebody else's problem that one train derailed going right to left and a different engine derailed going left to right both both in same place! Solly Cholly!

[tangerine-jack]

Hmmm, yes Bob, but why only that one loco? Perhaps the loco's parts are expanding and contracting causing the problem? Too wide a gauge on the drive wheels? I was under the impression the track ran downgrade into a 120deg curve, then the loco derails, not through the curve first then upgrade. I may be wrong. What is the slope of the grade? I don't think Ian could have missed installing expansion blocks of some type in this area, but it's possible. The track is stock LGB, I doubt there is anything wrong with it. Maybe Ian can mail his RR to North America for analysis[;)]

It is hard to diagnose such a problem over the forum, if I could put an eyball on the track and loco maybe I could pick up a visual clue. How about a couple of photos of the affected track area and the loco coulplers Ian? Thanks.



[oX)]

[Anonymous]

Gentlemen;

What a breath of fresh air; after reading all that rubbish from the Coffee Shop boys, thanks for your input.

Don't forget i got the tender for Christmas last year and this combination has been working quite well up to about a week or so ago.

I like to run it at speed 8, it suits many other things, but at speed 7 it doesn't seem to do it much at all and at 9 it is very unstable.

I have read what everyone has said and there have been some good thoughts, so i will tell you a bit more; that is even more puzzeling.

1/ It doesnt like right hand bends or too many of them. My area 2 which is a circle; you can run it around anticlockwise as much as you like with very little trouble. But clockwise it doesn't like, all right bends.

2/ My area 3 which is a complex figure 8 it also handles ok, but not as good as the anti clockwise run where it is doing left hand bends alll the time just about.
.
3/ The tender seems to be right up the Stainz' bum all the time as i observe it going around, instead of sometimes in tension and sometimes pushing as it should be.

4/ Whenever it derails the front of the Stainz is off the track pointing to the left of the track and the tender is off the track pointing to the right whicjh looks like a jackknife to me.

HJ what affect do you think back EMF would have on this problem?

I am having a time soon when i will be doing some MTS (Multi Train System) programming and i think if I crank the Stainz up a bit or drop the tender back this should help a bit, what does everyone think? Please advise.


Rgds Ian

[RhB_HJ]

QUOTE: Originally posted by iandor



HJ what affect do you think back EMF would have on this problem?

I am having a time soon when i will be doing some MTS (Multi Train System) programming and i think if I crank the Stainz up a bit or drop the tender back this should help a bit, what does everyone think? Please advise.


Rgds Ian

Back-EMF settings will influence the behaviour of the engine and/or tender on the downhill and uphill portions. If the tender has a tendency to run-away on the downhill while the engine is "retarded" then you will also have the weight of the cars in the train added to the tender and as the engine goes into the curve it will slow yet a bit more.

Now I know from members on the RhB Forum that trimming the MTS decoders to behave in an acceptable manner when double-heading is almost impossible. Which is why many people junk all that stuff and install something that behaves as expected.

OTOH you may still have mechanical problems, however I also know from others that MTS is not very forgiving of heat. Something to keep in mind in case you plan on MTSing on top of Uluru. [}:)][;)][:)][:D]

[ttrigg]

HJ

My attempt at "double heading" was over 20 years ago, and I'm most certainly sure that things have improved in that arena since then.

[rayf]

Ian i wonder if we are experiencing somewhat of the same problem mine being the brake car idea ????? good luck rayf

[Anonymous]

Ian.
I would think that it is an EMF problem on your tender as HJ says.
If the tender is pushing the engine down the hill it could be a prob

[Anonymous]

Yes gentlemen some good thinking and I take what you say about back EMF, HJ a very good thought.

However don't forget that it has been running fautlessly for nearly a year until about a week or so ago so something must have changed!

I have had an idea and i don't know what you men think but what about if i runit in reverse both ways clockwise and anticlockwise and see what happens and also try to observe the coupling if it goes into tension etc.

If what i think is true the tender will pull the Stainz and the problem should disappear, what do you think?


Rgds ian

[ttrigg]

That sounds like a well thought possible solution in finding the base problem.

[tangerine-jack]

Only one suggestion, log what you did each time and the result in a notebook, then you can build a trouble shooting chart for the next time it happens.

I agree that changing the direction of the push-pull should reveal if it is the culprit, which I suspect it is.

(Don't kill me for this Ian, but even LGB breaks once in a while!)


[oX)]

[Anonymous]

Gentlemen

LGB does go wrong quite often particularly when MTS is involved; and I think this is what has happened.

I ran the tender and loco around the track for a long time in reverse and it never derailed; the coupler went into tension and compression alll the time as it should so; i think we are heading in the right direction what do you blokes think?

If I look at the MTS instruction CV 2 covers starting voltage and it is set at the factory at "0" or slowest, what if I increase the Stainz to "01" and see what happens?

CV 3 and 4 control accelaration and braking and are factory set at "3" what about if i leave them as is and see what that does?

What do you think men and Rene.


rgds ian

[Puckdropper]

Can you disconnect tender and engine? That may be the easiest way to tell if they're going the same speed.

How hard is MTS to reconfigure? Sometimes you get the best results by trial and error.

[RhB_HJ]

Hellllllllllllllllllllllllllllo, the CVs to adjust the Back-EMF are CV60, 61 and 62!

To compare the relative speed uncouple tender from engine, separate by 2" then let run over the same section that gives trouble.

Programming speed curves happens with CV67-94. LGB recommends the 55045 programming tool for the PC.

BTW another fluky thing that could happen on the downhill/curve scenario is: tender and train pu***he engine. Frontend of engine lifts just slightly, but enough for the wheels to climb at the next curve!

[Anonymous]

HJ I think thats what it is but i wouldn't dare adjust the CV you are talking about that is out of my league. I will try CV 2 and see how i go!

rgds Ian

[Anonymous]

Gentlemen

You can all have a beer on me, i have fixed the problem! Hooray.

I set both the tender and the Stainz to the factory settings ie

CV 2 speed to 0
CV 3 accel to 3
CV 4 brake to 3

I then reset the Stainz speed to 1 and it didn't do anything much.

reset Stainz to 50 and it ran away from the tender

reset Stainz to 10 and it was still a bit fast

reset Stainz to 5 and it was just right, ran around the track for several circuits and the distance between the two remained constant at speed 8.

I then connected the coupling up and ran them in a clockwise direction which where all the trouble was. Ran very well the draw bar was straight just about all the time in and out of tension and comression all the time and it swung briefly to one side then the other as it went around corners, exactly right.

I have now run them for several hours in a clockwise direction and not even the hint of a derailment!

I also ran them all over my entire layout and as far as I am concerned its fixed


The only explanation I can offer is that as the tender is much newer than the Stainz it had run itself in and therefore exprienced a small increase in spedd enopugh to do the damage!
Rgds Ian