Märklin Motor Modification (MMM)

The part rotating with the highest speed in a locomotive is the rotor or armature
from the locomotive motor. The front part of the rotor axle run in the brush holder
plate which is made out of plastic. The other side of the rotor axle has another
plastic/bronze insert in the frame or in the older locomotives directly in the frame.
Both sides need to be lubricated very carefully and frequently to prevent the
running noises, especially the front in the plastic from the brush holder plate.

LFCM (Large Flat Commutator Motor) in a 7186 turn table.

Here is an older HAMO motor in a loco. The front axle is secured by a Benzing ring.

New style brush holder plate in a Drum Commutator Motor (DCM).

Insert in the loco frame

This is how the insert looks

Here is a bronze bearing insert ...

... replaced by the tiny ball bearing.

Little, tiny ball bearings can change the motor characteristic dramatically.
Especially the noise reduction is great and the maintenance is decreased to
almost zero. On the picture two ball bearings with 1.5mm or 2mm inner diameter.

Ball Bearing installed in a new style brush holder plate. The existing hole need
to drilled out slightly smaller then the outer diameter to hold the bearing tight.

The frame side of the loco could have an insert, a 1.5mm or a 2mm hole.
It depends what style of rotor (commutator) is installed, a hole has to be drilled
slightly smaller then the outer diameter of the bearing to hold the bearing.

Ball bearing installed directly in the frame.

I designed a tool for all the different motor shields to make my job a lot easier.

The motor shield is fixed by two pins to drill exactly in the middle of the existing hole.

Low speed drilling and very sharp drill bits are mandatory.

Here is the ball bearing pressed in the motor shield (386940).

Five pole HEP motor with ball bearings in a Märklin 3056 "Crocodile".
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Märklin Gauge 1 Motor Ball Bearing replacement.

Some of the gauge 1 or Maxi motors are discontinued. Most of the problems are
the worn out ball bearings at the armature shaft. The single bearings are not
available as a spare part. I found a source in Germany where I can order some
special bearings because the used bearings are not standard measurements.

The motor from a Märklin Gauge1/Maxi steam loco.

... here from the back side.

The ball bearing in the back ...

... and a much smaller one in the front.

A puller tool is needed to pull the old bearings off

New ball bearings custom made because the original parts are not available.

Both bearings are replaced.

The motor back in the loco, very quite and runs great.

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... will be continued.

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