# Adding A Smoke Unit For An HO Scale Locomotive



## cool74 (Apr 1, 2018)

Hello everyone! How difficult is it to install a smoke unit in a HO scale steam locomotive? The one I'm looking at has on board sound but no smoke capabilities. Please advise.

Thanks!


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## gunrunnerjohn (Nov 10, 2010)

I suspect that depends on the specific locomotive. MTH has smoke in a number of theirs, they have an HO specific smoke unit. Here's one from my parts box.


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## Bwells (Mar 30, 2014)

Since no one has answered, I will give it a shot. You mentioned it has on board sound so I would assume this means that the loco is DCC. Since it is a steam engine I also assume that the decoder is located in the tender. My suggestion would be that you would have to add 2 more conductors from the tender to operate it, possibly from the F3 function.It may be possible to use one side of the headlight circuit for the common and only one conductor would be required. I'm not sure if you can wire it in parallel with the headlight but that would be the way to go. The two smoke units I had required more than 10 DC volts to operate but as I ran them at less, they were somewhat of a joke. After not filling them and still receiving voltage they burnt out.
Here is a link to a Seuthe unit but measure your stack as they make many different sizes.
https://www.google.com/search?q=seu.....69i57j0l5.9867j0j7&sourceid=chrome&ie=UTF-8

What model are you looking at?

OOPs John beat me to it!


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## gunrunnerjohn (Nov 10, 2010)

Bwells said:


> Since no one has answered, I will give it a shot.


So, I'm a nobody now!


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## Bwells (Mar 30, 2014)

No, and I edited my post.


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## MichaelE (Mar 7, 2018)

Has anyone here ever tried to fit one of these units to a modern diesel locomotive?

Dark smoke coming out of the top of a modern diesel would really be something to see.


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## wvgca (Jan 21, 2013)

MichaelE said:


> Dark smoke coming out of the top of a modern diesel would really be something to see.


Unfortunately you would get whitish / grey smoke, not dark at all ....diesel or steam ....:cAnada:


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## MichaelE (Mar 7, 2018)

Is there no type of fluid that would produce black smoke?


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## wvgca (Jan 21, 2013)

MichaelE said:


> Is there no type of fluid that would produce black smoke?


Not as far as I know, most are glycerine based ,which is whitish smoke ..


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## cool74 (Apr 1, 2018)

Thank you for the information.


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## cool74 (Apr 1, 2018)

Seems like quite a bit of hassle to add a smoke unit. Still would be cool to have though.
Thanks


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## cool74 (Apr 1, 2018)

Bwells said:


> Since no one has answered, I will give it a shot. You mentioned it has on board sound so I would assume this means that the loco is DCC. Since it is a steam engine I also assume that the decoder is located in the tender. My suggestion would be that you would have to add 2 more conductors from the tender to operate it, possibly from the F3 function.It may be possible to use one side of the headlight circuit for the common and only one conductor would be required. I'm not sure if you can wire it in parallel with the headlight but that would be the way to go. The two smoke units I had required more than 10 DC volts to operate but as I ran them at less, they were somewhat of a joke. After not filling them and still receiving voltage they burnt out.
> Here is a link to a Seuthe unit but measure your stack as they make many different sizes.
> https://www.google.com/search?q=seu.....69i57j0l5.9867j0j7&sourceid=chrome&ie=UTF-8
> 
> ...


Seems like quite a bit of hassle to add a smoke unit. Still would be cool to have though.
Thanks


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## wvgca (Jan 21, 2013)

cool74 said:


> Seems like quite a bit of hassle to add a smoke unit. Still would be cool to have though.
> Thanks


I've got factory smoke installed in a few older DC steamers, but not DCC units ...
You can pick those DC units up complete fairly cheaply on online auction sites, but I don't think they are under 100mw so that they can be run off a DCC function directly without a final pass transistor..
Running off the DCC feed itself you would probably need some diodes to reduce the voltage seen by the smoke unit, and of course a power switch for times when you have no fluid or don't want smoke


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## mopac (Feb 24, 2011)

Be careful with smoke units. Most get hot. I have 3 or 4 Bachmann steamers with
melted smoke stacks. I only use smoke units now on locos with diecast boilers.


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## gunrunnerjohn (Nov 10, 2010)

Bwells said:


> No, and I edited my post.


Just having a little fun with you.


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## gunrunnerjohn (Nov 10, 2010)

MichaelE said:


> Is there no type of fluid that would produce black smoke?


This has been pretty widely discussed in multiple forums. To my knowledge, there is no realistic way to produce black smoke that wouldn't pose a maintenance nightmare. The white smoke is vaporized mineral oil, the black smoke would have to be a product of combustion. Unless you're going to be running live steam on your HO railroad, I don't think the smoke will be black.


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## CTValleyRR (Jul 26, 2014)

cool74 said:


> Seems like quite a bit of hassle to add a smoke unit. Still would be cool to have though.
> Thanks


Honestly, having seen quite a few of these in operation, I have to say that the feeble wisps of vapor coming out of a stack, often not synchronized with the piston movement, doesn't really do it for me. If you've ever seen a real steam loco belching steam and smoke under a heavy load, our little model units just don't measure up.

GRJ hit it on the color, though. The units we install should be called "vapor" units, not smoke units. Even if you were to use a black colored liquid, what would happen would be that he liquid would vaporize (into white-ish vapor) and the pigment would be left behind, gumming up your smoke unit.


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## gunrunnerjohn (Nov 10, 2010)

I don't know about your experience with MTH HO smoke, but I've seen some decent smoke from them. They obviously won't match larger scales, but you can't really expect that.


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## CTValleyRR (Jul 26, 2014)

gunrunnerjohn said:


> I don't know about your experience with MTH HO smoke, but I've seen some decent smoke from them. They obviously won't match larger scales, but you can't really expect that.


I don't have a carefully catalogued list of what I've seen and what I haven't. But I have seen many over the years and have yet to see one that I would consider acceptable.

Add that to the mess it makes and I'm happier without.


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## gunrunnerjohn (Nov 10, 2010)

Since you're happier without the smoke, I can see that you'd be hard to satisfy!


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