After running my BR41 for the first time in over a year I also discovered it would leave the track [ outwards ] when negotiating the 5140 points, I tried it on several different points on my layout and the only way I could make it track was by fitting a 25mm diameter lead fishing sinker on top of the funnel, The extra weight held it down so it had to follow the correct path over the frog.
Has anyone else had this problem and is there a correct way to fix this. After adjusting the guard rails I still could not cure the problem?

Dereck.

Edited by moderator 02 January 2018 09:01:21(UTC)  | Reason: Removed capitalisation on topic header - typing in caps is like shouting at everyone!

Have you checked the spacing between wheel flanges? I suspect that the BR41 wheels lose their gauge. My BR41 used to be my main steam engine on my layout until it started derailing on some turnouts. So since I use Rocrail I just excluded it from the affected routes. Then it started derailing on other turnouts and subsequently on R1 radius curves. The only explanation for me is that this means the wheels are slowly getting out of gauge.

I have not confirmed this since it has been sitting on the shelf since I could no longer even have it go around the layout once without derailing. A project for another day.

Happy New Year!
Peter

Any chance we can see a crisp clear picture of the underside of your loco please? IE: "feet in the air".

I checked the flange spacing's and I am sure they were wider than my std Marklin flanges. Juhan, its from the 29815 set as mentioned in my other post about its lights. I am certain the problem is as a result of the distance apart of the front and rear axles on the solid frame, in combination with the wider spacing's of the flanges.
I have been running quite a few 2 rail rolling stock and I tweaked the guards rails to pull the wheels over further [ and that worked ]. I have now decided to close up the spacing's on all the 2 rail stuff to the same gauge and the Marklin.
I will look at those flange spacing's again and reset them. We have friends and family staying at home at the moment so Marklin withdrawal symptoms [ my wife's words, not mine ] have to be moderated at the moment.

Ill keep you posted.

Thanks for all the feedback

Peter and Ake, don't let it beat you. That's a really nice loco and shouldn't remain a cripple for the rest of its like. Time to have another look. We all need each others help here. Ake, another day is here.

Dave can do easily now.

Once again, thanks fro the feedback

Happy new year everyone.
We had a big day at Waipu yesterday, got rained out at 2;00 but my new pupil got a 4th and a second out of 14 players in his first competition. I'll let you all figure out what that means. Ake , Angus, Adrian and Jeroen should have a good idea.

Dereck

ALL FIXED NOW. Even the point which still appeared to be a problem is letting the fully assembled loco through without derailing now.


the dreaded multi-grips

Dereck

ps I have seen some headers changed to let people know problem solved or sold. How do you do that please?

Good to hear from you Ake. Hope its not too cold over there right now.
Dereck

Hi All

@ Dereck: glad you fixed it. I have a BR 41 from the set 2995 manufactured in 1995.


It is a beautiful loco with a small design flaw: the coupling rod is too long to be rigid (on newer Marklin locos it is not in one part but two parts).
The result is the coupling rod prevents the full lateral play of drive wheels to adapt to sharp curves (you can check this on the upside down loco.
So it works but "just".

The problem is worse when:
- the coupling rod is slightly bent
- the screws to attach the coupling rod are too short (bad screws or result of too forceful tightening).

Solutions:
- adjust the coupling bars to obtain the maximal lateral play on driving wheels
- increase the lateral play by screwing the screws with Loctite but not completely all the way ON THE REAR DRIVING WHEEL ONLY (the front one is in danger of colliding with the distribution gear and the master rod).

Note: on newer Marklin Locos, to attach the coupling rod , they use 2 different screw sizes, the shorter one being for the driving Wheel where the interference with rods is possible. Unfortunately this newer generation is a smaller size screw and cannot be used here in this case.

Belated happy new year

Jean

Hi Dereck

Yes it is slightly flexible with your hand but the small weight of the loco is enough to make it derail (unless you use additional weight). I believe on this loco the adjustment is really critical. This is particularly true with M track where rail joints are not perfect in curves and can cause more problem than on C track which much more precise.
Bonne chance

Jean

Hi all,

Thanks for all hints. The 13,8mm spacing between flanges seems to work.
Wheels are too loose to the axles and move too easily so I glued them with Locktite 290.

But it didn't cure the tilting tender of course, so I added two thin lead sheets
into it and now it works just fine.
Now the "shelf queen" is pulling some coal wagons again

All the best from snowy Finland

Åke

Hello Dereck,
Mine used to do the tender thing. I added some weight inside and the problem was solved. A few years later it started to do it again .
I swear that this Lok is possessed.
I think I'll call it Derailpest!
Mikey

Hi Åke, Dereck, Mickey,

I may be wrong but I had this problem on a few Märklin locos with tenders.
Usually in the course of maintenance or upgrade of decoders the cables between the loco and the tender are squeezed so that not the right amount of play is given.
This is worsened by the new decoders with more electrical functions (more cables):
- Wheel sensor, cabin lighting, smoke generator, gear illumination, etc.
So the key is:
- the use of ultra flexible cables,
- their very neat arrangement in the coupling bar (on newer models a loop on the bar allows all cables to be installed parallel in a flat arrangement).
- the cable loop at each extremity of the close coupling bar to allow a smooth movement of the coupling bar
- the lubrication of the close coupling mechanism
- the presence of the spring of the coupling bar to bring it back in line
- the aging of cables which makes them less flexible than when they were brand new (the insulation coating becomes less flexible)

On older style locos like the BR41 the key is to verify the flexibility of the link between the loco and tender (both angular and in "S" shape since there is no close coupling.

Åke, I may be wrong but I have serious doubts that increasing the holes will help you, it will increase the distance between loco and tender when pulling and decrease it when pushing the train which may result in additional frictions between the bodies of loco and tender and thus further derailment causes. It will also cause extra cable fatigue by this new longitudinal play.

Cheers

Jean

Good points made here. I will look at the problem tonight. I agree about not drilling the holes bigger. Would mean more play. Maybe make another draw bar with the holes slightly further apart. Lets have a look before we decide. Wiring could be the problem. i did find the coupling had gone fairly rigid when I noticed the problem and possibly because I refitted the tender while still on the curve. The front bogie had displaced to the outside [ right in this case ] causing the shoe to short out. I pressed the stop button on the MS2 when I noticed another loco had stopped as well.

Previously, while diagnosing the derailing problem, I hadn't had a problem when the loco was reversing round the track.

Dereck

I had a look tonight. Decided the wiring might have been too tight so drew a bit more out of the tender when I had the top removed. My tender has quite a heavy cast piece of metal sitting inside and secured to the base. It ought to be heavy enough. Decoder sitting on top. I set it up on some 5100 and 5106 track to see how its looks. I feel the draw bar on mine is long enough. There isn't any where the loco and tender contact that I can see but they are close.
Oh well. time will tell. It took at least 2 hours of running before it derailed.

Dereck

41 029

Hi Ake. At least if the longer draw bar doesn't work, you can refit the original.

Hi Jean, thanks for that. I agree,. How you have shown how much free movement is required explains the problem. Mine didn't originally have extra cable length. It does now but probably not as much as you have demonstrated in your pictures. I suspect if everyone having problems with their BR41's looks at this thread, they will be able to eliminate all their problems.
Dereck