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Power Functions wagon for small LEGO trains

Two of my favorite LEGO trains are the #10254 LEGO Creator Winter Holiday Train from last year, and the train from the #79111 LEGO The Lone Ranger Constitution Train Chase set from 2013. They are very similar old-style steam engines, each with a coal car, a flatbed wagon, and a closed-in wagon. I like them because they are smaller and cuter than regular LEGO trains, but still run on normal LEGO tracks. 🙂

Speaking of running LEGO trains, the fun you can have with them increases exponentially when you motorize them. LEGO sometimes releases trains with LEGO Power Functions components already included with the set, and at other times, they release trains without Power Functions, but they include instructions on how to motorize them (all this takes is swapping a few parts out, as the train is already designed with Power Functions in mind). And in some instances, the train is not planned to have Power Functions, so LEGO fans have to figure out on their own how to motorize them.

The #10254 LEGO Creator Holiday Train is not motorized out of the box, however, it was designed with Power Functions in mind. The last pages of the instruction booklet show you exactly what you need to get the train motorized, and step-by-step instructions for installing the Power Functions components. And the set does include a full circle of tracks, so all you need to get is the Power Functions components: an #88002 LEGO Power Functions Train Motor, a battery box (either the regular one or the rechargeable one, see at the Online LEGO Shop), an #8884 LEGO Power Functions IR Receiver, and a #8879 LEGO Power Functions Remote Control. The whole kit adds up to $55 (or $92 if you get the rechargeable battery box).

To motorize the #10254 LEGO Creator Holiday Train, you replace the underside of the engine with the Power Functions Train Motor, swap out some parts in front of the conductor’s compartment to accommodate the IR receiver, and insert the battery box into the coal car. Then, you run some wires between the engine, the IR receiver, and the battery box that you stuff into the conductor’s compartment so they are less unsightly.

The #10254 LEGO Creator Holiday Train is small, so hiding the Power Functions components is not as easy as in larger LEGO trains. However, LEGO designers did a good job integrating all the parts as much as possible, and I think most LEGO fans would be very happy with the official solution. I really like the look of the original train though, so I wasn’t so happy with the light-gray section that the IR receiver added to the engine, and that the battery box was still slightly sticking out of the coal car. Plus all those wires running in between took away the space for the conductor. So, I was looking for some other ways to motorize this little train.

In the meantime, my other favorite train from #79111 LEGO The Lone Ranger Constitution Train Chase set was sitting un-motorized, because it was not designed with Power Functions in mind. While some trains are easy to motorize even if LEGO doesn’t provide instructions, the Constitution was not one of them. The coal car could hold the battery box the same way as in the Holiday Train, but the engine would take quite a bit of rework to include the train motor and IR receiver.

I have looked for instructions and watched some videos on how to motorize the Constitution but wasn’t really happy with any of them. I love the look of the engine, and the changes it required to accommodate Power Functions was just too drastic for my taste. Then, I found a video where Jason from the BrickShow reviews the set, and at the end, he quickly rigs the train to motorize it by just stacking up the train motor, the battery box, and the IR receiver, and adding the whole contraption at the end of the train. Yes, it’s ugly, but it allows the train to run without any modifications, and without unsightly wires running between the engine and the coal car.

This made me think; what if I just build an extra wagon for my trains that hides the train motor, the battery box, and the IR receiver all in one place? This way, I wouldn’t have to modify the trains at all, and all I have to do is hook up the extra wagon to the back of the train (or anywhere else between cars). The most obvious choice was to build a closed wagon, like the caboose on the Holiday Train, or car with the sliding door on the Constitution. Then just use the train motor on the underside of the wagon, and pack the battery box and IR receiver inside. With larger LEGO trains, hiding the Power Functions components in a wagon is not a problem at all, as the wagons are usually quite large. However, the Holiday Train and Constitution are smaller, so I wanted to keep the size of the extra wagon as small as possible.

The LEGO Power Functions Battery Box is 4 studs wide, 8 studs long, and 4 bricks tall, and the LEGO Power Functions IR Receiver is 4 studs wide, 4 studs long, and close to 4 bricks tall. So, putting them back to back, and leaving some room for the wires, I concluded that the wagon needs to be a minimum of 12 studs long, 6 studs wide, and 5 bricks tall (not including the roof). The 12×6 footprint also happens to be the minimum needed for the train motor, so I decided to go with this size. Please note that this is the absolute bare minimum, which allows putting walls on the two sides of the wagon to hide the Power Functions components, however the end of the battery box and some of the wiring will be slightly visible at the front and back, as they are 12 studs long together. This didn’t bother me, but you can always make the wagon a couple of studs longer to hide everything.

At this point, you can just build a generic wagon with all the Power Functions inside, and then hook up this wagon to any of your trains to motorize them. I decided to get a bit fancier, and match the design of the Constitution wagon, and the Holiday Train caboose. Note that I left part of the roof open. This is so that I can access the on/off button of the battery box without having to remove the roof, and I also found that the IR receiver had a more reliable and greater connection distance with the roof open. You can’t really see these openings unless you directly look down on the train.

I’m happy to report that hooking up the extra Power Functions wagon at the end of the Constitution and the Holiday Train operates perfectly fine and works even at full speed forward or backward without derailing the train. I can even pull all the cars of both trains with one Power Functions wagon. I prefer to put the wagon at the end of my train, but you can put it anywhere between the other cars as well. All in all, I’m very satisfied with this solution.

Please note that this solution is for smaller, lighter LEGO trains like the #10254 LEGO Creator Winter Holiday Train, and the train from the #79111 LEGO The Lone Ranger Constitution Train Chase set. Full-size LEGO trains generally need better balancing, and it is still best to put the Power Functions components inside the engine. But for smaller trains, or trains that are too difficult to motorize in the conventional way, adding a Power Functions wagon is likely all you need. This way, you don’t have to modify your trains at all, and you can easily swap Power Fuctions between them.

If you want to add a Power Functions wagon like I did, I would suggest that you build a generic car that could work with all your trains. Something like the design of the Constitution wagon works really well, as it fits with pretty much any train from any era. You could also build extra “shells” to match the design of your different trains, and then just swap out the battery box and IR receiver in between them, which is quite easy to do. I ended up buying an extra train motor, battery box, and IR receiver, so I have two fully powered train wagons for my two little trains.

If you don’t have the LEGO The Lone Ranger Constitution, I highly recommend it. It really is my favorite LEGO train – cute in every way! Although it is retired, you can pick it up for a very reasonable price at secondary marketplaces like eBay or BrickLink. The #10254 LEGO Creator Winter Holiday Train is from last year, so it’s still readily available at the LEGO Creator section of the Online LEGO Shop.

What do you think? Do you have the #10254 LEGO Creator Winter Holiday Train and/or the train from the #79111 LEGO The Lone Ranger Constitution Train Chase set? Or any other of the smaller LEGO trains? How do you like them? Do you motorize them? Or would you like to? And what do you think of my solution of building and adding a Power Functions wagon? Feel free to share your thoughts, questions, and comments below! 😉

And you might also like to check out the following related posts:

{ 36 comments… add one }
  • rainey November 21, 2017, 1:08 PM

    How very clever! I added a passenger car to the Christmas train too. I just thought it needed one other than the caboose. But mine is merely a passenger car modeled on the one on the 10173.

    Any discussion of Lego trains should have the advisory that they won’t operate with Duracell batteries. Does that sound insane? I thought so too when I called to complain that my train would only work for a few seconds at a time. They told me I needed to switch brands on my batteries. I, of course, told them that couldn’t possibly work but they replied that there’s a micro difference in the stem of a Duracell and any other battery. Skeptical still, I changed the batteries and LOW and BEHOLD, the engine ran!

    I don’t know why they don’t add that advisory in North America but I thought I’d spread the word.

    • brickmaster November 21, 2017, 1:35 PM

      Really? I never heard this before! Thanks for the info!

    • admin November 21, 2017, 2:51 PM

      That’s very interesting. I didn’t know that either. I usually use rechargeable batteries, but sometimes I use regular batteries as well, but I guess I never tried Duracell. Will keep that in mind for the future. Thanks for sharing!

  • brickmaster November 21, 2017, 1:36 PM

    That’s a great solution! I really like the idea of just having an additional train car. This means that the engine doesn’t have to be ripped apart every time I want to change power functions between trains. I wonder how well this would work with larger trains.

    • admin November 21, 2017, 2:50 PM

      Yes, that’s one of the reason why I choose this design. If you don’t have separate Power Functions for all of your trains, this is an easy way to swap out the PF components between trains.

  • DavidH November 21, 2017, 2:05 PM

    Very nice solution. Is that a sticker or printout of the elves in the windows? Did you put that there to cover the battery box?

    • admin November 21, 2017, 2:49 PM

      Yes, that’s just a piece of paper I slipped in there with a printout of some elves. Later, I was thinking of changing that to shaded windows, but at the time of building the wagon, those window panes were not available in a solid color.

  • Hayato November 21, 2017, 2:26 PM

    Are the rechargeable and the regular battery boxes the same? So this method could be used for both?

    • admin November 21, 2017, 2:48 PM

      Yes, they are the same size, so they can be used the same way. 🙂

  • Håkan November 21, 2017, 4:02 PM

    My friend thought that the PF parts were too big and bulky, and hard to implement in your builds.

    At least wireless technology should simplify things…

    • admin November 21, 2017, 4:41 PM

      I read that the whole PF system is going to be overhauled soon. I don’t know what this means as far as size, but the thing is that we always need to somehow house enough batteries and a motor. Perhaps the IR receiver could be made smaller though. What really needs an overhaul is batteries themselves. It’s really holding back advancement in so many areas of technology.

      • Håkan November 21, 2017, 7:52 PM

        Ah, yeah… I guess electricity in itself could be pretty green and clean, as long as it’s generated properly…

  • Darren November 21, 2017, 4:07 PM

    Very clever! I am pleasantly surprised that the extra motorized car can be put at the end of the train instead of closer to the front.

    • admin November 21, 2017, 4:42 PM

      Darren, yeah, I was pleasantly surprised too. I don’t know though if it would work as well on larger trains, but perhaps two extra wagons could be added, one towards the front, and one at the back. And maybe the engine could be weighted down some to make sure it doesn’t derail. I have seen that LEGO fans fill the engine with pennies on very long trains. 😀

  • Laurie November 21, 2017, 8:02 PM

    Looks AWESOME. Sadly we do not have a train set yet. however my little guy got a Lego Duplo train set for Christmas this year.. Maybe next year I would get one for my older kids, however there are a lot of awesome sets we are considering for future…

    We have 6 bins full of legs and we got all the Lego elves sets ever sold in store and online, and the same for Scooby Doo. My kids are big fans of Scooby Doo.. most of Lego batman movies sets just missing one.. Ninjago we got both the city and bounty, can not wait for the brick bank.

    Status Update, Just submitted our creative design ”Ideas Inspire Imagination ” By RaphLuna 😉 it was a ton of fun to create. The entries all look JAW Dropping AWESOME, Good Luck Everyone…

    Hugs 🙂

    • admin November 21, 2017, 9:35 PM

      Yeah, I’m seeing some really good entries! I didn’t see yours, but it’s probably not approved yet. Will look for it later. 🙂

      • admin November 21, 2017, 9:37 PM

        Never mind! I just found it! That looks really-really good! I also like what you did with the description! 😀

  • Matt November 25, 2017, 9:13 AM

    Great article. It was very helpful! We are getting the Constitution for Christmas, and I bought the power functions as well, and I’ve been looking for the best way to add these. This certainly seems like the best way to go! Thanks!

    Do we know about when the overhaul of the PF system will take place? Should I perhaps have waited on buying PF…?

    • admin November 25, 2017, 9:41 AM

      Matt, I’m not sure when the PF system will be updated, but LEGO indicated that they are planning to consolidate all their robotics and motorization systems. In one sense, it doesn’t really matter, as the PF system works very well, and is quite open-ended due to using regular batteries. And the components are reasonably priced too. It is not going to be like when the 12-volt system was replaced, and we had to get new of everything. As long as the shape of regular batteries remains the same, we can always use the PF system. I would not hesitate getting PF system components even at this point. Mindstorms is another matter though. I wouldn’t invest in Mindstorms right now, as it is expensive, and is going to be replaced as well.

      • Matt November 25, 2017, 10:57 AM

        Good to know, thanks! And thanks again for the great article! Super helpful!

        • admin November 25, 2017, 11:14 AM

          Matt, you’re very welcome. Have fun with your train! 🙂

  • Alison November 25, 2017, 2:50 PM

    Thank you for yet another really useful article. I have had my eye on the Constitution since a previous article where you wrote of your fondness for it. Your praise for it here has prompted me to finally take the plunge and I have just ordered a new set from Bricklink! I am super excited about this and I just hope that it arrives before Christmas!

    I like your ideas of how to install the power functions into these sets. TLG’s solution for the winter train was really disappointing and to me spoiled the look of the set. So now I have another Bricklink project to work on 🙂

    • admin November 25, 2017, 2:58 PM

      Alison, I’m positive that you will really enjoy the Constitution. It is such a lovely train! It has the same color engine as the Emerald Night, but I actually like the Constitution better. Who needs big trains, when these littler ones are so awesome? 😀

  • Alison November 25, 2017, 3:55 PM

    I agree with you about the size! And I just love this style of steam train with the big funnel, cow catcher and so on. Just wondering if you might have a parts list of the pieces required to build each of these extension wagons?

    • Alison November 25, 2017, 4:02 PM

      Well I have just found this which will help enormously, it is an LDD file of a similar creation for the Constitution: http://www.moc-pages.com/moc.php/420115
      I think that is all I would need as the exterior is easy enough to work out.

      • admin November 25, 2017, 4:17 PM

        Oh, interesting! That’s actually pretty cool! Larger than the wagon I built, but that means that everything will fit comfortably. 🙂

    • admin November 25, 2017, 4:06 PM

      Alison, I actually had all the extra pieces needed for the Constitution wagon. I only had to buy some pieces for the Holiday Train wagon, as it has some special colors and pieces. It’s pretty much just those wood looking bricks (1×2 and 1×4), and four fences that I used for windows. The rest are just plates, and some curved slopes on top. But if you are not sure about something, feel free to ask. 🙂

  • Ben November 29, 2017, 9:06 PM

    Do you have a parts list to make the car for the holiday train?

    • admin November 29, 2017, 9:13 PM

      Ben, so sorry, I don’t. I never made an LDD file, as this was an easy modification. If you have the Holiday Train already, then look at the instructions for the cart. The powered cart basically has the same pieces, it is just that the body is a little longer (it doesn’t have the roof overhang). So, you will need two sets of five windows instead of three, and bit longer 1-stud wide plates and bricks (or some extra) for the decorated sidewalls. The roof is the same, except for the opening in the middle. It shouldn’t be hard, but if you get stuck, feel free to come back and ask. I’m happy to help. 🙂

      • Ben November 30, 2017, 1:52 PM


  • MaLuChaNn December 8, 2017, 4:54 PM

    Are all items required to “power up” the train for motion? I mean, do I really need the remote control if all I wish to do is to allow the train to go around and around the track when turned on. Thanks!

    • admin December 8, 2017, 5:50 PM

      The most essential are the motor and the battery box. They will make the train go around like you described, but you will not be able to control the speed at all, and the train will go very fast at its full speed. So fast, in fact, that it might derail. You really do need the remote and the IR receiver to be able to control the train’s speed, as well as being able to turn it on and off remotely. It is a system that is compatible with all other LEGO sets, so it’s not like you would be wasting your money to power just one train. In addition the remote and IR receiver are really not that expensive.

      • MaLuChaNn December 10, 2017, 11:49 PM

        Thank you for the response! I will get the whole set. Happy holidays!

        • admin December 11, 2017, 12:30 AM

          That’s awesome and a great decision! Happy Holidays to you as well. 🙂

  • Hannah April 4, 2020, 5:58 AM

    Do you have a list of parts for the 2nd wagon you made for the constitution by any chance?

    • Thita (admin) April 5, 2020, 1:35 PM

      Hannah, sorry, no, I don’t have a list of parts. But it’s super easy to build. If you want to figure out a parts-list for shopping purposes, I suggest that you first built it in LDD (LEGO Digital Designer), which will give you a list of parts.

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