Need help to convert M.N CLASS R2204 to DCC.

[Mac90]

Hi everyone...This is my first time of asking for help.I have a merchant navy class locomotive that is not DCC fitted it is model number R1087-38-06, could anyone please suggest which decoder I need to convert it to DCC with sound if possible, if this is not possible which decoder to simply convert it to straight DCC.

I am ninety years old, have just taken an interest in model railways, I have some knowledge of electronics and circuitry, Any help would be most appreciated.

I have a track and DCC controller and a couple of models already running, they were easy to convert as they were DC ready.

[Mac90]

I am sorry that MN class Locomotive should read R2204........ the R1087 was the actual train set number....put it down to my age...sorry.

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[Simmo009]

Hello and welcome Tom. For a cost effective sound decoder, the Hornby TTS one will be fine. EKM Exhibitions have the one you need in stock at a very good price. Or you can go full fat with a specialist, but you will be looking at around £100. For fitting, I would suggest checking if you have a local club, if you do there will be someone there to help you. A small donation and a packet of biscuits will engender goodwill (it does at ours).

Good luck, keep us informed.

[Going Spare]

When enquiring about fitting, check that there is room within the loco body to fit even a decoder without modifying the body as this was one of the very early Merchant Navies produced by Hornby before DCC came in to vogue. If you wish to fit a speaker as well, it may necessitate either running wires through to the tender, where there is space for both decoder and speaker although there will not be specific provision for either, or substituting a smaller speaker for the Hornby TTS one.

This thread may benefit from being moved to the DCC section of the forum.

[Bulleidboy]

R2204 is 35020 Bibby Line, as Going Spare has already said, this is an early Hornby re-built Merchant Navy. The internals of the body are different from later DCC Ready/Fitted rebuilt M/N's. Again as has already been suggested you might find fitting everything in the tender easier, which I am sure has power pick-ups from the tender wheels - you would still require wires to go to the motor. I recall that the red and black decoder wires go to the track pick-ups, and the orange and grey go to the motor. There used to be a very good instructional guide from Bromsgrove Models - using Bibby Line, but I cannot find it, and have a feeling they closed the site down.

This may help - go to Youtube and insert fitting dcc to hornby merchant navy class

[ColinB]

I have converted all my old Merchant Navy locos to DCC and in fact I am doing two at the moment, Port Line and Brockelback Line.

On these type there is no room in the loco for a DCC socket, you can make room by cutting back the weight mounting (this is what Hornby did on their later DCC fitted models in the loco) but I wouldn't recommend this. Fitting the DCC decoder or even a sound decoder is a pain as there really is not enough room and you might break the valve gear trying to do it. So the best idea is to retrofit a DCC socket into the tender. Now with all my locos I like to do it so that the loco doesn't look modified so I will explain how I do it.

Buy a Hornby x6113 lead or a a equivalent off EBay. Connect the wire in the loco that goes to the pickup to one of the outer wires on the x6113, connect the ground connection/other pickup wire to the other outer wire. Now connect the motor to the two inner wires of the x6113. Buy a Hornby x9958 tender connection socket. Now open up the tender and you will see the wire that goes to the drawbar pin. Snip this off and lever off the pcb it is attached to from underneath. Snip off other wire to drawbar. Now cut a rectangular hole in the tender for the socket to fit, making sure the front edge of the hole is where the tender base front bulkhead is. Cut the hole in tender plus tender base, being careful when cutting the tender base that there is enough plastic left to prevent it from splitting. Fit x9958 and drill a little hole 1.6mm diameter to take the self tapping screw to hold the socket in place. Now wire the socket to the DCC socket plus pickups. Two outer wires to pickups and pins 4 and 8 on the DCC socket. Make sure that the pickup on the tender connects to the right pickup on the loco when the lead is in place or else loco will short out. So if you wired right outer pickup on loco to outer pin 1 on plug, so tender right pickup must go to outer pin 1 on socket. Wire pins 1 and 5 of the decoder socket to the inner pins of the x9958. Mount the DCC socket onto the weight by a plastic holder of tape. I use threaded studs but that involves drilling and tapping of the weight which is more difficult. Finally when all wired up screw socket down and do continuity check on DCC socket (covered in outer posts) to make sure you don't have the pickups connected to the motor (DO THIS WITHOUT A HEADER SOCKET FITTED TO THE DCC SOCKET).

That is how I do it. There are probably easier ways.

[Fishmanoz]

It is possible to do this more simply than Colin has described above but he has good reason to do it his way. It is so he can use the current standard Hornby parts being the 4-pin plug and socket now used to transfer pickup and motor connections between loco and tender when the socket is in the tender.

Pickup transfer between loco and tender already exists in this model via the older fingers on the drawbar arrangement. You could leave this in place (Colin removes it) then you only need 2 wires, orange and grey, to go from the socket in the tender to the motor connections. But maybe someone else can say if there is a 2-pin plug and socket available for this.

Then Colin’s continuity testing is to achieve two aims:

• that you haven’t swapped pickup black and pickup red between loco and tender as this will short out the loco, and
• you don’t have a stray connection between pickups and motor connections as this will blow your decoder instantly.

Finally, I’m surprised no one has suggested an HM7000 decoder yet - HM7000-8 for non-sound or HM7000-8TXS for sound (superior to TTS and priced between TTS and full fat mentioned).

[Going Spare]

Hornby did, very briefly, use a 2-wire plug & socket on the Britannia (S/S 289) but while the plug is available (expensively) as X9606, the socket was supplied only pre-fitted in the tender chassis frame.

[ColinB]

Yes going spare I did consider using the 2 pin version in my original build West Country/ Battle of Britain locos to remove that dreaded pronged drawbar., but as you say you cannot buy the circuit board separate. In these locos there is more than enough room to mount full sound in the loco but those dreaded drawbars are always causing issues putting shorts on the loco when one of the prongs inadvertently touches the pin. In the end I even went with the 4 way lead although I only use the two outer wires. I did use the two pin on another loco as I had an old Britannia tender where I converted the loco to decoder in tender (again very little room in loco to fit sound decoder).

[Mac90]

Thank you everyone for your fantastic response and help, I am very grateful for all of your suggestions and I now have a plan of action in my head of what is necessary for the conversion.I will keep you informed of how things go.

You have all been very kind and generous with your help and I really do thank you all very, very much indeed.