Classic UK Minitrix Models  -  Motor
General Service
 

A patent oil dropper. I place a little oil onto a plastic lid, and dip a small pin or screwdriver into it. You can just make out the curve of the liquid on the screwdriver blade. Possibly a little too much here for the purpose of the photograph.

Rest the blade against the shaft of the motor axle. The oil will flow off the blade and into the brass bush. Here seen before it has had chance to get drawn into the tiny gap between bush and axle. Give the worm gear a twist, and then wipe away any excess. Then spin the motor to distribute the oil. The trick is to get enough oil to the bush without any spare seeping through to the inner workings of the motor.

I loaded the screwdriver and took another shot to show the effect To add this drop to that already on the axle would be far too much. I didn't. I wiped it off after the photo. These modern cameras are very effective at showing close up detail when in zoom mode. Its much easier to see than with a hand lens! That is my excuse for the amount of debris on the worm gear. With the naked eye, it looked to be clean.

The motor is held in place with two spring clips. Do not try to bend these clips - they will break. Put the clips into position and aply gentle, even pressure to both sides. Effected here by a central push with a small screwdriver.

The rear view of the motor with the clip in place. Don't try to force the clip - it will break. No warning, spring steel is like glass - it gives up to a point, then suddenly shatters.

Do you see the two little indentations in the back of the motor? Make sure yours are visible. They are a 'This Way Up' mark for the motor. If you don't check this, your loco will still work, but it will go backwards when you ask it to go forwards and vice versa.

Brushes. The 9F motor is very similar to the ivatt Motors, but the end caps are at the gear end of the motor on the 9F version.  However, they do use the same springs, brush caps and brushes - part number - 40015900. You may still get some from ebay.

If not, make your own. See information on the 'Other Information' menu - follow Key Parts and select 'Brushes' from the right hand menu.

Brushes.  Although round, I suspect (but don't know) that the Graham Farish N gauge brushes and springs (Part No 0129) may be adapted to fit.
Update - Denm contacted me via the Visitors Log Book and confirmed that the Farish bushes do indeed slot into place without the need for any modification.

The picture on the left is linked from http://www.lendonsmodelshop.co.uk - who list this part and also list some spare bits for Minitrix.

Motor Connections are managed by this little device which bridges the rear of the motor where the brush caps are. It makes contact with the pickup strip at the base and transmits the power to the top and bottom brushes. A capacitor sits across the brushes and a choke coil is inserted between the positive pickup and the bottom brush,

The beauty of this little engine is the electrical arrangement. No wires - this little housing does it all. But note how it fits. I've labelled the larger photo - (click the thumbnail), and this photo is taken before the housing is finally located. The bottom of each side press onto the bits of the copper contact strip at A. Strip B makes contact with the bottom brush cap of the motor. When reassembling, make sure that this contact is made and that the end of strip B doesn't poke inside the armature of the motor itself.

The contact on the left hand side. Another strip makes contact with the top brush cap.
Not the lug which is sticking out below the plastic housing, and the square hole into which the lug fits. This is not a push fit - the sides of the housing have to be eased open slightly to allow the plastic to slip over the lug....

... which is what I am doing here on the right hand side. A little pry and support will allow the lug to fit in its proper place.

And here again on the left hand side. Difficult to see in this photo, but check that the two contact strips at A (3 picures back ) are actually in contact with each other. Check also, that the contacts are not touching either the rear wheel or the motor housing.

Maintaining Classic UK Minitrix Locos
The Minitrix trademark is currently owned by Märklin Inc.  Gebr. Märklin & Cie. GmbH, Stuttgarter Straβe 55-57, D-73033 Göppingen, Baden-Württemberg

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