Hornby Dublo Duchess

[SuperD]

Good evening all,  I've recently acquired a couple of HD Loco's, "Montrose" and "London", both two rail and non runners.  The magnets are weak and I realise a remag' will be required.

I thought I'd start by cleaning everything and then a little Lub' to the bearings.  I had no problem removing the armature from "Montrose" and cleaned  it with a plastic tooth pick and cotton buds, added new springs and brushes, a touch of oil on the bearings, reassembled and set about 1mm of "end float". Put power to each brush....nothing.

With "London"  it briefly burst into life with power to the brushes but with a squealing noise that seemed to be coming from the commutator, there isn't a groove in the chassis top so I can't remove the armature without removing the wheels, which I don't want to do.  Is there some "trick" to this?

Any help/advice would be very much appreciated.

 

Regards

John

 

[RAF96]

The squeal is usually the shaft bearing. Tiny drop of oil required.

If you have a multi-meter put it across the brushes (on the Ohms scale) and rotate the motor slowly by hand. You will see the reading flicker as the commutator moves brush focus from armature pole to pole. The valid readings should be around the same, say 100 ohms - ish. If you have direct access to the commutator simply meter between segments. It is likely a winding has broken.

[SuperD]

Hi RAF96, thank you very much for the reply.  Having lubricated overnight I had another go with "London" and she set off like a good un',  speed gradually increasing.  However, after about ten minutes running flat out, the squeal returned.  There is "end float" but I can't see any ball bearings.

"Montrose" no joy.  A neighbour has a multimeter so I'll ask him to oblige.

The thing that concerns me is not being able to get the armature out of "London" as I can with the Duchess.  Fortunately things seem to have worked the right way for me in that respect.

Once again, thank you for your input.

 

Regards

[TinTracks]

Hello John

 I'm a 3 rail lad myself so I've never had my  hands on a London.

I've just had a quick look in the Michael Foster Dublo Bible. He reckons the motor was re designed for the London model. I've checked out the parts list and drawings and at first look the only difference in part numbers between Duchess and City locos seems to be the top adjustable bearing (the screw threaded bit) I wonder if you remove the  top adjustable bearing completely the motor will then come out?

 I've had the odd screechy 3 rail loco but as RAF 96 says a clean and a  dab of oil usually does it.

Just a suggestion but if you post this in Vintage/ collectable there are quite a few knowledgeable chaps who may not have seen your question here. Scroll down a bit in the V and C section and there's a thread called Hornby Dublo.

 I'm a bit busy at the moment but later tonight I'll have a look through my stash of chassis and make sure I don't have a London Lurking. 

   Hope this helps a bit. Regards, Rich

Edited October 25, 2021 by TinTracks

[TinTracks]

Hi again.

 You may well have this but here's a link to Lendons of Cardiff website. Scroll down a bit and there's down loadable links to the Dublo service sheets. Duchess is number 5, City is number 12

 

http://www.lendonsmodelshop.co.uk/?button=button2&servicesheets=none

 

  Regards, Rich

Edited October 25, 2021 by TinTracks

[SuperD]

Hi Rich, thank you very much for your input, very helpful. I shall look at the link.

The only difference I can see in the motors is the larger top bearing on "London".

Regards

John

[DCB]

I have had H/D Duchess locos for well over 55 years.  They squeal when the commutator slots get bridged and they run with a circle of sparks all round the commutator which is very obvious with the body off.   Weak magnets are the base cause making the motor draw too much current.   Fortunately you can fit super neo magnets to the existing pole pieces.   I use any old super neo magnets from computer disc drives etc, The ones sold by the trade are too strong and wear the armature bearings.  They do like their proper suppressors or a nice big ceramic capacitor if the original has gone missing.    The Duchess tender drawbar is hopeless, it lifts the back of the loco while pulling, mine pulled 3 tin plate coaches out of the 5 I owned on the level originally and with modified drawbar now pulls 8 up a 1 in 33.  or 24 modern coaches on the level.  The city one is much better.

If you remove the wheels remove the INSULATED ones. The non insulated tend to work loose on the axle if disturbed and become insulated if you loctite or epoxy them back in place.  Its a lot cheaper to replace bushes than complete wheels. Actually Romfords make  big difference, pole pieces might need filing off a bit but  I used 26mm romfords with Triang crank pins, standard rods opened out to suit, centre wheels drilled for H/D insulated crank pin bushes and valve gear assembled just as standard  with Airfix castle bogie wheels and Jackson trailing wheels and scale spacing for the tender which still  goes round 1st radius makes quite a beast.   What it lacks detail wise it makes up for in realistic pulling power. Lets face it 16 coaches was quite a normal load for the real thing....