Derailing problem.

[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

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]

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 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.

[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)]

[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

[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.

[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)]

[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 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]

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.

[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.