Union Pacific Big Boy 1:38

[Bricksonwheels]

When it comes down to scale modeling with Legos a lot has happened over the last years. Its more and more recognized as a true scale modelers medium, and I think that is great. About three years ago I decided to build more different things then only the trucks that I had built so far. I built Harley Davidsons, Hot rods, and started with trains.

After the two big 1:16 scaled American diesels, I thought it would be nice to have something dynamic for events: A true scale locomotive on actual Lego rail gauge. I opted for the Union Pacific Big Boy: (<a href="https://en.wikipedia.org/wiki/Union_Pacific_Big_Boy" rel="nofollow">en.wikipedia.org/wiki/Union_Pacific_Big_Boy</a>).

There are already many models of this type of locomotive but I wanted one for myself as it has always appealed to me since I was a kid. I did some math calculating back from the Lego track gauge, coming to a 1:38 scale.

Building such a big locomotive to run on Lego rail is a bit of a challenge. I had to deal with the following facts:

-The standard Lego curve is too tight for such a long locomotive. Therefor I chose the Radius 104 aftermarket rail.

-The wheels are not existing as such. In diameter 45 mm there is nothing available from the shelf. I worked together with Jaap Kroon to design and 3D print a set of custom wheels. To make it look more realistic I chose to add the valve gear as well. We designed the valve gear with Lego compatibility in the back of our heads. It should not become too fine compared to the bricks.

-Power. This thing is heavy. And it has a lot of batteries to add to the weight. The solution was three genuine Lego Power Functions XL engines directly geared to the axles of the tender. I chose the tender to push the locomotive as it was much more convenient to house the engines and batteries there. In order to get all the ‘juice’ to the engine I chose a regular RC Battery pack and the Tamiya connector was hooked up to a PF cable. To control it I mounted a SBrick, so there is no restriction of battery power in the whole system.

-Lights. I wanted to add some realistic lights as well. Initially I wanted a smoke generator but the proper 5V kit was not available anymore, so I dropped it (for now). Rob from Brickstuff.com supplied a very cool lightkit for the locomotive.

It includes a dimmer for the contour lights. All in all there is about 2 meters of wire in the locomotive. It took me about 2.5 months to finish.

Specifications (locomotive and tender)

Length: +/- 106 cm

Width: +/- 9 cm

Height: +/- 13 cm

Bricks: +/- 3400

A big thanks to Rob @ <a href="http://www.brickstuff.com" rel="nofollow">www.brickstuff.com</a> and Jaap Kroon for the 3D printing support.

[efferman]

Wow! does it drive through standard lego curves?

[Bricksonwheels]

Nope, It runs on MEmodels R104 ones. On my Flickr, you can see the first tests in a video. I managed to limit the swing a bit later on.

[Sven J]

WOW!!!!

This is gorgeous! :wub_drool:

Is it possible to show some more detail photos?

[garethjellis]

Wow. This is wonerfull!

[mrseven]

This loco is amazing. Wunderbar!, I have only a little questio: Would you be so kind to share the .stl files on thingverse or shapeways ?

[Bricksonwheels]

Thnx all.

I will shoot some more in the near future.

[Tommy Styrvoky]

Great job replicating it, I have seen one in real life, and it is probably one of my favorite locomotives. Have you tried testing how powerful it is at pulling cars/ weight?

[Bricksonwheels]

Hi Tommy,

It can run very slow with the tender, so there is a lot of power. I have a water tender under construction which will also be coupled. I think it could pull up to 7 or 8 cars in this scale.

Edited June 12, 2016 by Bricksonwheels

[dr_spock]

Sweet. Very nice. How does it look with a minifig engineer and brakeman?

Have you tested it on LEGO switches?

[xboxtravis7992]

This is very spectacular. Awesome dialed to 11.

[marbleman]

Wow, that really a "big boy", I like all details of it, that is like a train model more than Lego MOC. The only pity is picture is less, hope to enjoy more details of it.

[Bricksonwheels]

Thnx all. I will add some additional shots today on my Flickr pages (www.flickr.com/bricksonwheels).

Edited June 13, 2016 by Bricksonwheels

[monai]

Awesome model, like all your works, certified personally by Christiensen!

only one question: since you have rightly produced the wheels and rods that Lego doesn't make, why have you not concluded the work and produced a real functionig walve system? I see only the eccentric crank and eccentric rod and a pseudo expansion link but not the radius bar and the walve stem.

wit my best compliments

[Edwin Korstanje]

This is a absulute mind blowing good model Dennis :wub:

Good to see you building more and more outside your comfortzone.

[Man with a hat]

Oh WOW! That's not only huge but amazing as well. What a pack of details!

[Bricksonwheels]

@Monai: The reason for that is that I aimed for a design that was still close to Legos look and feel. Adapting the whole valve system would have required too fine parts, and would have put the design out of balance. Lego is not too fine in detail, and I thought so should the design of the 3D printed parts.

It would however have been possible. Maybe in the future.

Edited June 13, 2016 by Bricksonwheels

[LEGO Train 12 Volts]

Wow I love the Big Boy and this is the best lego model I've ever seen!

The wheels are stunning and the rods details gorgeous!

The lights and the bogies are the icing on the cake!

Perfect work!

[Feuer Zug]

A fitting tribute to a fine steel masterpiece.

[monai]

@Monai: The reason for that is that I aimed for a design that was still close to Legos look and feel. Adapting the whole valve system would have required too fine parts, and would have put the design out of balance. Lego is not too fine in detail, and I thought so should the design of the 3D printed parts.

It would however have been possible. Maybe in the future.

I beg your pardon if I cite myself but let me invite you to see at http://www.eurobricks.com/forum/index.php?showtopic=115207#entry2343753

a functioning walve system is possible, I've cut something and made by hands the rods , you have printed by yourself some pieces with much better finesse so your results are smoother and more elegant, but the possibility is real.

I love the way you have produce the right scale feeling, definitely these wheels are a must for train lovers.

regards

[Bricksonwheels]

@Monai: You prove my point that it is possible. Yours looks good. I decided to keep the system like this, as it appealed more to me.

[harnbak]

What ... a ... brute!

[Bricksonwheels]

Thnx Harnbak!

[3D LEGO]

Bricksonwheels,

You have designed and built a beautiful rendition of the ALCO 4000-class 4-8-8-4 articulated steam locomotive for Union Pacific. I like how you used the scale and smooth surfaces to your advantage in order to use studs for things like stay bolts on the firebox. Am I correct in assuming the coupler is of a larger scale model type? I love the characteristic Boxpok drivers and the simple yet working drive train. From the videos and pictures I would safe to say it is plenty powerful. The lighting adds that nice finishing touch to the model. Seeing as it is #4014, I am sure it will not be long before someone at Union Pacific Railroad takes note of it. (They are only rebuilding #4014 as we speak.)

My one critique concerns the front and the use of the cowcatcher part. That kind of design had been long phased out and the Big Boy had a very rudimentary, solid version that does not protrude very far. I do not know if you tried alternate brick-built versions or not but perhaps you could. (For one it would allow you to include a coupler up front.)

3D LEGO

[Bricksonwheels]

Indeed 3D Lego. This particular one will run again in the future. Hope to see it one day!