Removing Rivarossi Big Boy body for DCC decoder fitting

[Seacommander]

I have recently purchased a Big Boy (HR2884) and would like to remove the body to fit a decoder.

I have located the two screws accessible from underneath the loco but despite my best efforts I cannot release the dome to access the screw underneath. It is very firmly fixed and I have lost a small piece of plastic flashing trying to remove. I don't want to cause any more damage!

In the DCC topic area of the forum reference was made to an body removal article in the International topic area - I have scanned all the contributions but am unable to find it. I expect it is hiding in so called 'plain sight' but would appreciate any help in locating it.

Thanks in advance for any help.

[P-Henny]

This video shows the dome being removed in milli-seconds just using his fingers, didn't even need the use of a fingernail as a lever, So either your dome is glued on [by previous owner?] or you are trying to remove the wrong dome part of the loco body moulding. Or you have a completely different version of this model and there are different body fixing arrangements.

Sorry but this YT presenter does prattle endlessly, but he does get there in the end. To save you a bit of time, the dome removal is at timestamp 4:27

Note that this video also has multiple inserted advert breaks in it that are rather annoying.

I haven't watched all 22 minutes of this video, but I had the distinct impression that the decoder goes in the tender not the loco, so the dome removal seems to be a bit of a red herring.

P.S I think I found the article referred to in the 'International' section, but it predates the forum upgrade. Thus the posted images in it are missing, therefore not of any use to you.

EDIT: Found this other YT for decoder fitting, seems to be a very complicated arrangement as a PCB needs replacing. By the way, the decoder in this video is in the tender.

EDIT: This second video is now known to not be the Rivarossi model version. The link is left in-situ for information only.

[Seacommander]

Thanks PH.

The exploded diagram of parts and brief instructions that are included with the loco clearly show that the decoder is fitted in the loco and not the tender. They also show that the dome needs to be removed to expose a fixing screw. The decoder can't be fitted into the tender because the connecting plug and socket is only 2 pin and not a minimumof the 4 connections for basic wiring of a chip.

I too noted how easily the dome was removed in the first YT video.

I have emailed a query to the Hornby Technical Team to see if they have a solution.

[P-Henny]

Sorry my reply does not appear to be much help, but it was posted in good faith.

I can only presume that the second video showing a tender located decoder was (being a USA video) not a Rivarossi branded version of the loco.

The first video presenter did say that he had already disassembled the loco, so maybe just for the video, the dome hadn't been fully fitted back in place to aid removal for the filming task. It certainly looked like it was an easy thing to remove.

EDIT: Just looked at Service Sheet HR2753. The dome appears to have a locking lip on it. With the loco cab on the right and the loco front on the left. To me, it appears to show that the lever to prise off the dome needs to be applied to the far side (right) of the dome. If you try to lever it up from the near side (left), the lever will be fighting against the locking lip that slips under the ring of the hole. Of course, it might be just the way the dome is drawn that suggests this.

[Seacommander]

No need for any apologies PH; it's good to be encouraged to review all of the possibilities and try to make sure the obvious hasn't been overlooked.

I did look at all the service sheets on the Lendon site but your comment made me re-visit HR2753 and indeed on enlarging the image there does appear to be evidence of a lip. I will unpack the loco again this evening and try gently prising from the right hand side, So far I only tried front and rear as these gave the easiest access.

[Seacommander]

Still being unable to remove the dome I considered that there would be nothing to lose if I removed the two screws underneath. Bingo! The body was off. Quite clearly there has been a change in design resulting in the abandoment of the screw under the dome and very disappointingly and frustratingly this has not been taken into account in the servicing sheets for the latest models.

Finally - the dome on the latest models is definitely not removable under any circumstances either being moulded integrally with the boiler or at the very least a separate part glued in place.

[P-Henny]

Congratulations in getting there in the end. Ironically my first reply had the answer contained within it when I wrote:

"Or you have a completely different version of this model and there are different body fixing arrangements."

[Seacommander]

Thanks PH.

Perhaps I am being too naive to think that the dedicated service sheet for the model would be accurate?

Maybe this thread will be of use to other similarly bewildered modellers!

[P-Henny]

Particularly if it is the paper one included with the loco from the factory. But then Hornby documentation is notorious for always being 'out of date'.

As you say, this thread will help others who follow. Particularly if you were to add an 'addendum' relating to the decoder socket access & installation experience.

[Seacommander]

Yes it was the paper one that comes with the loco.

One thing to watch out for once inside: you will need to disconnect the lead plugged into the on-board PCB that connects to lighting on the body. The lead is rather short and it makes for easier work if the body isn't 'flapping around''.

The on-board PCB is highly accessible. Simply remove the blanking plug and install a 21 pin decoder (or adapter for other decoders). On top of the on-board PCB and immediately under the blanking plug there is a small piece of dense black foam which I think is for cushioning and maybe preventing the decoder or blanking plug being installed on a slant. Depending on the component layout of the decoder it maybe necessary to carefully cut away some of the foam to enable the decoder to plug into the socket securely and without tilting.

[P-Henny]

thumbsupsunglasses

[Tim M]

Morning,

I must admit it took me a while to work out what screw under the smoke dome you meant.

This is a very old feature of the model and in honesty, the screw is no longer used for anything and you do not have to remove it to remove the body (You never did have to).

So apologies for the confusion, I've requested an amende service sheet is put on the FAQ center to stop confusion. The draft version is below showing we've removed the arrow and an indication about how to remove the screw under the steam dome.

In summary, you only need to remove two screws under the chassis to remove the body where you'll find the decoder socket.

Tim

[Seacommander]

Thank you Tim for requesting an amended sheet and hopefully others won't chase the red herring I did. One further suggestion for the amended sheet: perhaps remove the suggestion in the illustration that the dome is removable. The dome now appears to be an integral part of the body. This hopefully will prevent others trying to remove it and damaging the fragile part of the moulding where dome attaches to the top of the boiler. I did manage, annoyingly, to lose a small piece of this moulding in futile attempts to remove the dome by following the erroneous instructions on the service sheet. Are bodies available as a spare part?