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I have a MTH Rail King Scale engine that I an interested in modifying. Has any one ever done the following:

1. Added a Smoke unit

2. Adding an electrical tether between two engines, linking an A (powered unit to a B un-powered)  to extend the electrical foot print

3. Adding/moving an electrical coupler to a un-powered B unit?

I am happy to do this my self or pay some one else to do the work, you can be handy man or checkbook and sometimes a little bit of both!

Original Post

The model in question is the MTH SW9 that came out last year. 

I have the cow and calf units and I would to make them a little more prototypical. 

1. Added a Smoke unit to both cow and calf

2. Adding an electrical tether between two engines, linking an A (powered unit to a B un-powered)  to extend the electrical foot print

3. Adding/moving an electrical coupler to a un-powered B unit?

4. Weathering 

I would be very happy to pay some one to do this work for me, if any one can recommend any one


It could be done, but I'm pretty sure the board is right under the stack on the locomotive.  Getting smoke out of two stacks will require extra plumbing as well.  If the unpowered calf is like the ones I've seen, there's nothing inside.  No problem adding smoke, but you'll have to bring the control from the powered unit via the tether you speak of.

Almost anything can be done, it's a question of how much effort and cost you're willing to bear to enhance these units.

I can do this type of work, but here is your problem.  The Switchers that have smoke use a small smoke unit and flash code that support it.  Room is really tight in the switchers and all the brackets and mounting that support a smoke unit that you can easily do maintenance on is not a readily purchased item.  The smoke units I have. 

Then you need the flash code, but since this is not made for smoke I am not sure what the SF flash code supports.

The tether for a unit like this will also probably require coming thru the shell.  It will also require a bulky looking connector between the two units if we use MTH type.  I custom make harness when I need to but time is $$$.

I am also not sure what the trucks look like on your calf so a picture would help, but some dummy trucks are not made to take pickup which would also add time and effort to mount, and some are not set up to take electro couplers.

So how much do you want to spend on this?  Smoke units run $35 to 50 each, Funnel or custom funnel more $$, Couplers $12, Harness set up $20-30, Pickups $10 or some, plus labor. 

If the PS-3 flash code does not support correct smoke unit it can't work.  If there is no room in the Cow, same problem.  G

I am actually wanting to do the same thing on the same engine. But I don't want to tether them.

I am trying to get a sw1 so I can use its ps2 board and tached motor to make it powered only on the front truck. It will still look like a sw9 calf with its weird platform but it will have lights, sound, and could move on it's own if needed.

And I also plan on putting a smoke unit in both engines. These will be lashed instead of tethering them.

I am actually wanting to do the same thing on the same engine. But I don't want to tether them.

If you use the PS32 board instead of a PS/2 board, you can load the chain file for the small smoke unit, that will solve the smoke unit issue.  You still have many of the problems that GGG alludes to.  First things first, you need to be specific as to what exact models you have and where you want to go.

I think I may have a simply solution. I took apart my  MTH SW9 Cow and Calf. Looking at the guts, it dawned on me all I need to do it buy another  MTH SW9 cow any road name at all, ditch the shell, and put the calf shell on it, then make a lash up!  Smoke unit not solved but I can save that for another day. The Cab section is hollow and there are not parts that occupy that space so, the calf shell fist no problem! 

Now to just by another SW9 in a road name I don't care about. 

Tethering is a way of the past. Then they went to wireless drawbars and now they have DCS.

With 2 dcs boards, you can pair them without having to worry about a wire. If you use the guts from a tiny switcher like the sw1. It leaves room in the hood for a smoke unit.

The rear exhaust shouldn't even be blocked. Mind you, I am taking off the rear unneeded motor. Allowing you to do a very simple duct system.

I also plans to use the reversing headlight wire to put 2 red markers next the the headlight since it will never need one in the other direction.  The light will then automatically switch between headlight and rear marker.


If you put a calf shell on a cow. You will need to drill new holes as the cow has wider screw spacing on the cab end. Then you will need to fill the original holes as the will be exposed.

Plus, I don't think it will fit. The calf has a narrow rear area where the cab was. I don't think you will fit the motor in it with it being both, narrow and shorter.

This is really expensive to put a PS-2 board in just for smoke, but your railroad.  The PS-2 or 3 O diesel boards are the same basic size and big regardless of model engine.  There are no small boards.  Yes the S gauge board is smaller but a one off.  I guess if your just after smoke an lights in a dummy you could go HO board, but your going to have to go with AC version.  This is not easy to do as separate parts not easy to get.

The tether is easy.  Lights, coupler, smoke.  PS-3 does it with the early slave model.  Otherwise your buying a diesel kit, plus a smoke unit.

Just by a newer smoking switcher.  Cheaper to paint the shell then do the modes your considering.  G

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