Old dog new tricks, DCC for old trains

[tom_weston]

My first post.

My son in law mentioned digital trains for his son aged 4. This got me thinking about all my old trains, 1960's vintage double O. Is it possible to convert the old trains to run on the dcc system? If so is there a guide as to how to do it?

sorry if this has been asked before but I find it very interesting. I have loads of old track and engines so it would be nice to try.

Tom, age 62.

[Lyd 85B]

It is possible, with varying degrees of difficulty, but there is no one-size fits all method. You need to search online, where there is a plethora of information on converting particular individual or groups of models. This will need sifting through to find what you want, or you can ask for information on specific locos here. Much depends on the motor type and the route taken by current from the track to the motor. So-called split-frame, or split-chassis, locos are usually reckoned to be most problematic, but they can be done without too much trouble (though best avoided as a first attempt at conversion).

[Chrissaf]

I post this link purely just to give you a flavour of some of the complexities of older loco conversion. Note that this site used to be very comprehensive, but currently many of the conversion links go to a 'dead end', but worth browsing anyway.

http://www.bromsgrovemodels.co.uk/decoderinstallation4mm.htm

 

The principle is very simple, it is the execution of the principle that can sometimes be more difficult.

 

In principle. You trace out the electrical connection between the two track rails and the two sides of the motor. Break those connections, so that the motor is totally isolated from the track. Then connect the track connection path to one side of the DCC decoder and the other side of the DCC decoder to the motor .... simples !!!

 

OK what sounds simple in principle can be quite difficult in practice for the age of locomotives that you are referring to.

 

For example some of them might be using a 'split chassis' where both sides of the chassis split are electrically insulated from each other. Each side of the chassis then makes contact with a track rail via the wheels and one side of the motor. Thus in that situation there is no really convenient place where you can break the circuit to insert the DCC decoder.

 

Some locos might go half and half, where one side is via the chassis and the other side is via wiring. Again the chassis side has to be isolated from the motor.

 

Some locos (steam) might use the loco to pick up power from one side of the track and the tender to pick up power from the other side of the track with the motor typically being in the tender.

 

Old locos with what they call X03 / X04 motors are, out of the older loco types, one of the easiest types to convert.

 

It is only more modern locomotives I.M.O that can truly be considered 'DCC Friendly' when contemplating DCC conversion.

 

Then to complicate things even more, older locos tend to have motors that draw far more current than modern rolling stock. Thus suitable 'high current' decoders need to be sourced. This usually means looking at non Hornby decoders as the orderable range of Hornby decoders are only motor rated at 500mA.

 

So in summary and conclusion. Virtually any loco can be DCC converted if you know what you are doing and can identify the type (electrically) of loco that is going to be converted. That is to say, does it use a 'live chassis', how is the motor isolated, what is the electrical path between the track rails (wheels) and the motor. Thus what physical modifications need performing to the loco to achieve the necessary motor electrical isolation. It goes without saying. that a 'Multimeter' is a critical tool in the 'Toolbox' to have at your disposal if you are going to be serious about DCC converting locomotives, and 'how to use it' of course.

 

TIP: As a newbie poster on the forum, just be aware that the 'Blue Button with the White Arrow' is not a 'Reply to this post' button. If you want to reply to any of the posts, scroll down and write your reply in the reply text box at the bottom of the page and click the Green 'Reply' button.

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See also – further TIPs on how to get the best user experience from this forum.

https://www.hornby.com/uk-en/forum/tips-on-using-the-forum/

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[Fishmanoz]

Not too much searching needed, you've come to a good place to start.

 

As well as Bromsgrove, google Brian Lambert and check out his DCC pages including some conversion guides. This will be particularly helpful if some of your locos have Ringfield motors as some of these are tricky with the LH motor brush holder connected to chassis via the screw that holds it (a giveaway here is when there isn't a wire connected to this brush holder, only the RH one).

 

There are also some conversion guides on this site, mostly more modern types but worth checking out.

 

Two things to add to Chris's above:

 

-  When disconnecting pickup wires from the motor, remove any electronic components connected across the motor terminals (capacitors) or in series with one terminal (inductors).  They are spark compression components not needed for DCC.

 

-  Before conversion, always do a DC stall current test to see just how much current the motor is drawing, then fit a decoder that can handle that current.  Details in Brian Lambert.

 

Then some will tell you that you should fit a DCC socket to the loco first, then plug your decoder into that.  Makes it easier to change decoders or fit a blanking plug to go back to DC.

 

For X03 / X04 motor types Chris mentions, user Margate-Richmond has the definitive conversion guide posted on these pages (don't solder directly to the motor brush, use a clip like the one already fitted to the other brush).