Dear All,

After almost 3 years of z scale I am very pleased overall and have locos from Marklin, Micro Trains and American Z. I have two DB89s and one small diesel (8864). Two of the Marklin’s are 3 pole and one of the DB89’s is 5 pole. The two 3 pole locos have run perfectly since I bought them on eBay. The 5 pole DB89, which came with my starter set, has been nothing but trouble. It ran fine when I first got it but began to run slow and hot (sure sign of high resistance) after a few months..it eventually totally died and Marklin kindly replaced the motor (armature) under warranty (less than 12 months old). This ran fine for a while and now is doing exactly the same thing. This loco has been very well treated, cleaned and lubricated (very sparingly) when needed and always run with the correct Z scale controller at very modest voltages. Right now it runs fine for a bit then slows way down then speeds up…when running slow it gets very hot…I suspect a bad sector in the armature?

Question: is there some intrinsic weakness in the 5 pole armature that would be doing this? I am very much inclined to simply replace the armature again with a 3 pole version and be done with this problem.


Thank you...

Thank you..I would never have thought of that..i have carefully unbent (is that a word) the brushes..did a very careful lube again..seems to have helped...running nicely right now..let's see...but mine was doing EXACTLY what you reported in your previous thread,

Cheers

ps I thing I did do..with the head of a needle dipped in correct oil..I lubricated the BOTTOM end of the armature shaft (which they do not tell you to do). I was very careful to get the oil below that little shoulder above which is the commutator. The symptoms could all be slight binding somewhere too...

btw I do realise in this photo that the wheel contact strip is in front of the wheel when it should be behind..I have corrected that now...