Classic UK Minitrix Models  -  Break it Apart
or carefully disassmble

Here it is.  A none - working, messed around with, badly repainted Class 42 Warship.  It was once 'Hermes' - Amongst other things, the Greek God of Travel.  This model wasn't going anywhere in a hurry though.  Let's take a look inside.

The top screw keeps the body attached to the chassis, and it does this by providing a thick metal plate secured across the top, with a little screw hole in the centre.  The Class 27 doesn't have this arrangement, and I can't think what else the plate is there for - unless it supports the pantograph on German Electric trains that share the same chassis.  Possible.

This model has had the top circuit board removed.  The wiring is for a pair of replacement LED front and rear lights, and the 2.2k resistor provides the necessary voltage drop to prevent the LED from blowing.

A front view of the LED as found.  One leg of the LED has a sleeve on it, which wasn't providing much protection.  The half sheathed leg of the LED was very close to the chassis, was exposed near the LED and was free to vibrate around.  I reckon that this loco ran with a considerable stutter.

And here again, from the side. 

And at the other end of the loco, a similar arrangement, but a resistor and no insulating sheath.

The loco without its top, identifying the front and the rear.  Note the brass screws under which the LED legs are clipped.  They are on the nearside of the loco, and will serve to identify which side is which.  ie they are on the left side of the loco if the front is to the left - as in the picture.

Undo the 2 black flat head screws.  Note the locating pin peeping through the hole on the far left of the black metal plate.

Front side of the loco from above.  Better illumination.

And the rear side - LED legs removed from under the brass screws.

Lift off the rear worm gear cover .....

... surprisingly, this reveals the rear worm gear !  Note the two thick spacer washers.  The one at the right hand end can drop off when the gear is lifted.

Here is the front worm gear after the cover has been removed.  Note the two slots in the lugs in the chassis on the other side of the worm gear.  These are for locating the gear cover.

The motor is held in place by a bracket at the front and the rear.  Each bracket is held by 2 screws, so that makes 4 to remove in total.

Undo the front two screws, followed by the rear and gently lift the motor out by easing up the two brackets.  Be careful, the motor my not separate without lifting the gears spindle out.

See the slot in the plastic end of the gear spindle.  If this is not aligned up & down, the motor will lift the spindle up.  There is no way you can tell - just be ready for it.

Rear worm gear spindle, with the thick washer removed from the right hand end.

The front gear spindle is identical in every way.

The front bracket can be slid away from the motor body a fraction and then lifted off.  Note the small locating pin that we mentioned earlier.  This is the front mounting bracket.

The rear bracket is fastened to the motor with two screws.  No need to take them off.  The motor in the photo is as it should look.  The motor that I actually removed had a broken spring, which needed to be repaired.

Note the two contact strips for the power, the top end of the two brushes, and the spring arms which keep the top end of the brushes pressed outwards.  This in turn keeps the carbon brushes pressed onto the motor.  The brass stud is pressed into the fragile top of the motor, and is riveted from the other side.  Don't try to unscrew it.  It isn't a screw.

The top side of the motor showing the carbon brushes.  Plenty of wear left in these.

The bogies are secured with a dowel.  Push it out from one side....

...like this.....

...and viewed from above.   Note the plastic gear.  The dowel passes through the hole in the middle of this gear.  When you remover the dowel, the gear is free to fall on the floor, and their design ensures that they roll under the heavy object which casts the darkest shadow.  Be aware of this so that it doesn't fall off in the first place.

This is what it looks like when you have recovered it from the floor.  And that is what happens to all of that grease that you put on there.  It dries and hardens.

The front bogey also has a plastic gear.

Rear bogey - removing the single screw underneath ....

... to take off the cover plate to reveal wheels with brass gears.  Note the electrical pickup strip, and the insulation between the wheel and the axle on the nearest wheels.

More gears to loose.  Take them out and put them safe - 2 of them in each bogey.

The electrical pickup has quite a kink in it.  It shouldn't have, but is a sign that an attempt has been made to adjust its position, without taking the bogey off.

The pickups are part of the plastic block which sits against that square metal block in the chassis with the screw hole in it.

It can be lifted with gentle prying.  Here I use a sewing needle.  Later I found my smallest watchmaker's screwdriver to be better.

And here it is removed.  It needs some careful cleaning and straightening.

Showing the pickup block alongside the bogey.

The rear is very similar, but not identical.

The front and rear bogeys facing each other.  Now they are identical.  It is the fitting of the contact strips which are 'handed' which makes the front bogey different from the rear.  I'm not going to tell you which is which here - it is confusing.  I'll safe the confusion for when the loco is reassembled.

The lower circuit board is secured with a black plastic undertray, which has two thin legs protruding from underneath, through a small slot in the side of the circuit board and clipping onto the top of the chassis side.  They are very fragile, and the black plastic tag can be seen to have been bent over at some point.  Ever so gently ease the tab away from the chassis side, and simultaneously press down GENTLY on the circuit board floor until the clip moves down slightly.

This is what it looks like - the broken clip clearly didn't survive an earlier removal attempt, and is hanging on for dear life.  The other one doesn't look healthy either.  There is a lip half way down the chassis side which provides support for the circuit board.  On its way out, the plastic clips will snag on this, and may need to be eased gently over it.

The two protruding copper tags make contact with the strips on the underside of the motor that we saw earlier.

Here is the underside of the circuit board.  The strips at either end provide the power from the wheel pickups to the motor.  They need to be clean.  The coil and the capacitor are legal requirements to stop radio interference from the electric motor, and reduce the sparking from the brushes.  If fitting DCC, these two items must be removed.  Electrical interference is managed by the DCC chip.  But fitting DCC is a separate issue.

Here's the plastic support tray, with its broken leg.  In this state, it will not keep the circuit board pressed against the motor, so the contacts will be intermittent.  It needs fixing.  Easier said than done.

Here are all of the components laid out on a piece of greaseproof paper on top of my Ipad, which has the Torch app running underneath.

And again, all of the components neatly packed away awaiting cleaning and reassembly.

Maintaining Classic UK Minitrix Locos
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