Servicing, trouble shooting Hornby Dublo

Ron Dodds has published a series of videos on utube which relates to many aspects of running Hornby Dublo. They include, servicing, trouble shooting, track, couplings almost anything you want to know about running HD all done simply and extremely well.

Here is the complete list

Cleaning and Lubricating

Adjustment of carbon brushes

Fault Finding

Use of multimeter

Type of magnet

Getting more out of your motors

3 rail track fault finding

Metal couplings and wheels

Cleaning the rolling stock

Loco wheels and their problems

Great viewing for cold wet winter evenings.


9 thoughts on “Servicing, trouble shooting Hornby Dublo”

  1. It appears not to be widely known, judging by the prices asked/reached on eBay, but several HD screws are in fact Meccano parts (the body fixing screw for the 4MT tank for example) and are available as such, at much lower prices ( as much as 10p against £2 or even more). Heretically, a metric screw will do at a push and will cut its own thread – lubricate and go slowly. The spacer for the pick up assembly is a nut with a plain unthreaded hole, but a standard nut will do. At most a little filing is necessary.

    The long brushes are actuallyWrenn spares and intended for their puny undersized commutators together with a longer spring (these must be softer?). As stated in the video, they can be cut in half for Dublo, but care is needed. Guess who has managed to split more than one!

  2. Has anyone got details of the measurements ie diameters/depth etc of the fixing holes etc for the 8F? I have purchased an unfettled chassis and body and intend rebuilding it (almost literally) from scratch. I suppose I could take another one to bits and measure each bit individually but I’d like to avoid that if at all possible.

    It would be useful (in relation to David Simmons comment) for someone to produce a comparison table/cross reference guide so it’s easy to know which ones are needed. I don’t know if there’s any info out there already – I certainly haven’t found it.

  3. I recently purchased an HD Cardiff Castle, I think it has a ringfield 2 rail motor that been converted to 3 rail using a standard castle tender with plungers, what I don’t understand is that it runs reasonably well running forward, but, in reverse its slower than a snail and frequently stops. Being new to HD my electrical knowledge is extremely limited, Is the engine not suited to 3 rail ? or could it be the armature ? If any one has an idea what is wrong with this castle, I would really like to know 🙂

    1. David, I’m not the most technically competent HD person but lets start with what I know. Cardiff Castle was a 2 rail engine and thus has one set of its driving wheels insulated. If these wheels have not been de-insulated in the conversion then this will lead to uneven running over points and X crossings. This can be easily checked by carefully turning the local upside down putting one wire from your controller on the pickups and the other wire on one of the driving wheels. If both sets of driving wheels allows the motor to run they have been de-insulated but if only one set allows the motor to run then you still have insulated wheels. This is a relatively easy fix.

      The three rail Castles had a wire from the engine which plugged into a socket on the tender which is how the current got to the motor. It is possible that this is an area subject to a bodge so a picture would be useful. If the motor runs forwards then there is usually no reason why it won’t run backwards unless something is shorting. I think that it is unlikely to be the armature but I must admit to being out of my depth here but I can ask around and see if anyone has an answer

      1. Hi Tony, thank you for your reply, I have to confess the inside wiring of the tender is a very very bad bodge and will require complete rewire and new tender door.
        I did what you said to attach one of the controller wires to a tender plunger and a wire to a driving wheel,and as you explained, one is still appears to be insulated, we are talking the center driving wheels ? one conducts and one doesn’t. Anyhow if this is the case what needs to be done to uninsulate the driving wheel ?
        Kind regards, David Overton.

        1. Re your Castle.

          Let me just check the basics.

          On my 3 rail castle if I attach a crocodile clip from a wire from the controller on one of the tender pickups and then check the engine upside down on by bench. Touching the other wire to any of the driving and tender wheels will start the motor. If it is a 2 rail engine unmodified then the motor will only run when you touch any wheel on one side of the loco and tender, if you touch any wheel on the other side then it will not run which indicates that the wheels are insulated. If just touching one wheel sets the motor going then that has been de-insulated which might be case if you have erratic running.

          Now to de-insulate them.

          1) with the body off check if the 2rail pickups are in place – this is a piece of metal which just touches the backs of each insulated wheel and then a wire would normally go to the motor in a 2 rail application. If that pickup is still in place all you need to do is to wire it to the chassis to make an earth which would involve drilling a small hole and a small self tapping screw to hold the wire.

          2) Get someone to fit new de-insulated wheels and sort the tender – like Dennis Williams
 who does a great job but you will be in a queue.

          3) Buy some conductive silver paint / Carefully scrape the paint away around the axles and wheel centres of all the insulated driving wheels, using a fine point or a fibre glass pen remove as much of the rubber insulation as you can. This will enable the paint that you put on the axle and wheel to conduct the electricity and de-insulate the wheel.Test that the wheel is de-insulated as above and move onto the next one, including the tender. Having tested all the wheels and run it on the track use some matt black paint to cover up the silver paint.

          By the time you buy the bits it will probably be best to let Dennis fix it for you but you might want the challenge.

  4. Hi Tony, Happy New Year and once again thank you for your advice, I have given this problem some thought and in the light of what you said, I think it would be better if I contact Dennis and get him to rectify the problem with my locomotive.

    Kind regards, David Overton.

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