Servicing old HST 125 models (rear single drive bogie)

[Chuffchuff]

have been servicing some old HST 125 Intercity units which are non runners.

Following the YouTube advice I have dismantled and lubricated (sparsely !) the gearing and one HST seems to run OK. Unfortunately the other two, I managed to break the 2.8mm spade connectors, more like they fell apart so I have some on order) before I can test again.

I was surprised how basic the electrical connections were to the motor. The spade connectors seem to be fitted to “bumps” of metal, rather than something more sub substantial.

Is there a better way of making connections ?

I also was investigating the tail unit which squeaks as it runs. Taking look underneath, it would appear from the shiny axles that some lubrication is required.

A questioning thought popped into my head, quite how is an (sparsely!) oily axel suppose to conduct electricity? I would have thought that the oil would act as an insulator. I have a feeling Copper-ease may not be a good idea ?

Rgds

[Mountain Goat]

It was the standard way of doing it and it worked ok. With DC, a slight interuption on rare occasions was not usually an issue.it is only when DCC came along that one may have issues, but if one sets the inertia to zero and possibly the back EMF to zero, it will perform just like any other DC loco will and absorb any small interuptions.... That is if one is using DCC.
Lima soldered their connections which can be good but can be not so good, as the ability to just unplug connections and it all being nice and simple is easier. I do prefer Lima pancake motors to the Hornby ringfield motors for this one reason. Lima armatures can come straight out without the need to remove the drive cog from the shaft. This makes home servicing a tad easier if the motors happened to have been clogged up with tiny bits of metal that the magnet may have attracted over the years.
I once had a "Mystery" problem with one loco (Either Lima or Hornby or possibly Mainline powerbogie... I don't remember) only to eventually track it down to having picked up a stray Hornby track pin (Older smaller type of track pin) which was rather hidden from view. I had many issues and eventually stripped everything down and found it when I decided to even take the wheels off. It was so well hidden behind one of the wheels I just had not noticed it.

Other then that, and the need for fresh traction tyres for them to pull heavy trains, they seem to just keep going as long as they are cleaned and serviced.

Be aware when servicing that some oils may weaken the nylon (Or plastic) cogs.


Your question as to if there is another way instead of the spade connectors. On the motor they can be soldered but on the other power bogie would need some thought as the design is such that it would be difficult to alter it.

[Brian]

Hi
I assume this is a Ringfield motor (Pancake type)? If so, you will be very lucky to be able to solder any wires to the metal chassis. Hence why Hornby used nibs and 'push on' small spade connectors. Note spade connectors come in various sizes and you will need to obtain the correct size to fit the nib.

Lubrication should be kept to the motor drive shaft (both sides where the drive protrudes through the bearings in the casing. And to the pivots of the gear train.

Lubrication should be only be a oil sold specifically for model railway use. Never use spray lubricants like WD40 or thick oils such as 3 in 1 types. Remember the lubrication Golder Rule.... If you can see it (the oil) its probably too much! Use a tissue or kitchen roll paper to blot up surplus lubricant.

Clean the motors copper commutator with a soft fibre pencil brush or use Isopropanol Alcohol (IPA) of the 99.9% type on a cotton bud to clean the copper segments and also use a wooden cocktail stick to gently clean the slots between Comm. segments. Replace worn carbon brushes and their springs if the springs are weak. Peters Spares and other spare part retailers sell these.

Traction tyres can be easily replaced if slipping on the wheel or show signs of wear again sold by spares retailers. Clean all metal wheel treads with the the soft fibre pencil or use IPA on a cotton bud. In fact even if the fibre pencil is used on both the Comm. segments and wheel treads its a good idea to follow up with a Cotton Bud dampened with IPA for a final clean.

Lubrication of the non powered bogie is not normally be needed, but if you wish to only apply a tiny spot to the wheel bearing / axle and blot off excess with the tissue/kitchen roll paper. Cleaning the axles and wheels with a contact cleaning fluid or IPA should be all that's needed really!

[Chuffchuff]

Thanks for your replies and guidance.

Just to add to the woes !

Now sourcing a spring for the brushes! I swear it was in the box of bits until I came to put them in.

Rgds

[Chuffchuff]

My new springs arrived.

I undid my box of bits to start work

By magic I had two springs !

It would seem I did not look hard enough at the single spring to see that it was two springs wound together.

Lesson learned,( or is it learnt?) and maybe a useful tip to others.

Pleased to report, repairs and maintenance to date after your advice, are all working well.

Rgds

[Mountain Goat]

Haha. That happens! Nice it is back running again.

[RAF96]

You can fit a ring tag in lieu of the spade connector, then drill and tap the motor housing in a suitable place if such a screw is not already there.