And now

a brief parenthesis on the history of the prototype ...

At first, thank you to

dampflokomotivarchiv.de

for all the informations.

The loco was built in 1942 and was referenced as Br 50 2217 ÜK of the DR.

ÜK for Übergangskriegslokomotive meaning "Transitional war locomotive".

These kind of loco was simplified and light enough to be used in the context of war.

In 1945 the Br 50 2217 ÜK has been given, as a war compensation, to France,
to the "Administration des Domaines " and then referenced "1-150 Z 2217".

No existing picture of this loco nor of what kind of consist was pulled.

If you read french, yo can take a look at :

loco-revue numero-556

of 02.1993. (you can change of page at the bottom of the window)








Best Regards
Joël

Now opened...



well , not much things inside:
the front bulb
the contact plate for the smoke generator
and the DCM motor.




to solve the blocked wheels problem,
let's remove the rotor at first.

Two screw to remove:




don't forget to remove the two brushes


the three poles rotor is there:



Well some dirt on the poles
this proves that the machine has made at least a few turns

thank you for this additional informations.
It is important to be able to gather all the knowledge on a single model in a single topic !

Best regards
Joël

Hi Joél

I have had many times like new or new second hand bought locos with the same problems. Mostly locos from late 1980’s or 1990’s have this ”gear glue” problem. Very often in this same place is the worst jamming point between that big gear wheel and locos metal frame. Your method to fix this problem is very good way to solve this problem.

I have had also locos with grounding problems because there have been too much oil/grease between the wheel axles and the frame. In these cases loco does not run well on straight track sections but goes better on curved track sections. I have removed all axles and wheels and cleaned axles and frames axle holes/bushings with same methods/products and after this fix locos have started to run very well. In some cases that original Märklin oil/grease from the factory has also got to glue like jamming thing in the axles when loco has been sitting in it’s box for decades.

Cheers,
Janne

Hi Joël,

I use isopropylic alcohol (a.k.a. isopropanol) to remove old oil or dirt from gears or axles. It works very well, but all contact with paint must be avoided. The black color on most gearboxes or the livery would be dissolved easily, so I only use it on nickel-coated parts. For that reason, spray is not an option for me. On Ebay.de, I've seen a lot of locos from the 1980s or 90s that seem to have discolored gearboxes. I'm not sure if this is the effect of spray or some other solvent, or if Märklin actually made gearboxes that were not black at that time. In general, I avoid Märklin locos produced during those years though I still own a few. Over the last 10 years, I've serviced and sold most of those I used to have.

Too much oil on locos is still an issue nowadays. Modern digital locos often have grounding problems because assembly workers applied too much grease or oil when the loco was produced, as I've read in other MRR forums. According to Stummi Forum members, the problem disappears after a thorough cleaning.

Chapter 2 : the Big Grounding Issue !


Well As Janne and Mark said in their posts, these 1990's models tend to be subject to ground issues...
...and my loco is a very good example .

Let us have a look at the reversing unit input schematic:



The pickup shoe is under the tender and feeds the reversing unit with a red wire.

The reversing unit is grounded by a brown wire going to the loco,
this ground wire is connected to the loco metal chassis using one
of the two motor screws.

all the wheels of the loco connect the loco metal chassis to the tracks.
















Looks good... ...theorically

I agree Janne,
and for me this "too much oil which becomes glue and insulating coat"is terrific.

I have tried to clean my 3414 the same way I have cleaned all my previous models,
but no effect.






Soooo I have decided to find another solution and started my project:





and to modify the strange tender design that was originally:

Hi Joël,

Have you cleaned every gear and every axle? I would try isopropanol instead of ethanol. It's much more powerful as a cleaner than ethanol. I buy it at the local pharmacy; it's cheap and very efficient. In my opinion, WD-40 is not a real cleaner, but a lubricant. It's an oily substance that I only use on door keys and locks. I don't think that removes all the old oil, and on top of that, WD-40 is not a recommended oil for model trains, is it? If you use that, your loco will run again, but you'll add a new type of oil.

What surprises me in this thread is the grounding problems with locos from the late 1980s or early 90s. I used to have a lot of those, and in recent years I've cleaned and serviced some that I wanted to sell or still own, but I've never had any grounding problems with them. Could the WD-40 be the cause of those issues? The only loco I've ever had a real grounding problem with was a digital BR 01 produced in 2015. The old vintage locos I've cleaned with isopropanol now run very smoothly, and this process has also worked out for locos with blocked gears produced after 1980.

I've quoted your photo of the chassis seen from below because it shows the places that need to be cleaned with isopropanol. You need toothpicks to clean every tooth of every cogwheel to get the grime out. Just dip the toothpick into the isopropanol. Before you use the toothpicks, apply isopropanol with a cotton bud while you turn the wheels (the brushes being removed). I use cotton buds and hold them against the inside of every wheel, above the axle, so the isopropanol trickles down and dissolves the grease on the axle. Try to move the axles sideways. If that is difficult, there is still some old oil. Even if you can easily move every gear and axle, there is now WD-40 all over your chassis, and that might cause the grounding problems.

Once you have finished cleaning the loco, use new oil sparingly. I use Faller Spezial Öler, product number 170489.

Just in case all of this advice does not help and the grounding problems persist: can't you send the loco back to the seller and ask for a refund? In case you used Paypal, you can threaten to open a dispute and force the seller to take it back. Locos that are sold on Ebay are supposed to work, except if advertised as defect.

Hi Joèl and Mark

I don’t lubricate either my locos with WD40. For cleaning I use mostly some electric components cleaner. For lubrication I use also Märklin 7149, but I have heard some rumours that it can cause loco gear train jamming if loco will be unused for decades after applying it. If I remember correctly then this Märklin 7149 is not a synthetic oil. If it is mineral oil then it was this product which of I have heard these rumours. Actually I started to consider if I should change my lubrication oil for locos just to some synthetic lightweight (viscosity) motor oil.

But I use my locos more frequently than once in a decade or something like that or I at least try to do it. 1-2 times usage minimum per loco per year is my goal.

Best regards,
Janne

trying different solutions and finding a good setup for the silver spring....












The silver leaf spring is finally flattened with pliers, just after a black wire has been soldered on it.

Preparing a consist...

...to show you the results



Best Regards
Joël

Congratulations of your successful work!

Great idea for improving that original bad grounding. Thanks for sharing us your idea and showing the great results.

Cheers,
Janne

Edited by user 20 March 2020 15:47:31(UTC)  | Reason: typo

Hi Janne,

thank you for your help and advice,
and thank you for following the thread of this story !

Best Regards
Joël

Hi Joël,

It's true that alcohol, especially isopropanol, needs to be used with great care on MRR items. It damages plastic parts as well as paint.

Anyway, you've done a great job on your loco. It now runs better than what might be expected of an analog drum collector motor, and it will probably improve with time. I was intrigued by your thread because I used to collect this type of loco and I'm interested in analog locos. Documented stories like yours that include lots of photos and videos actually help other Märklin users assess which items they might (or might not) want to buy in future.