4-8-8-4 Big Boy Locomotive

by MakerBot Feb 27, 2014
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will a 200x200x200 bed printer work for this project?

it is possible to print it 1:32 scale ? any recommendations?

Does the wheels and rods move if pushed?

I love it, now i just need the big 3D Printer to build it as mine is to small. hehe

Meh, I've seen bigger...

(Seriously, that thing is awesome!! You rock!)

For anyone assembling the rail/ties using Paul's graciously supplied separate models for them, I've uploaded an alignment/spacing tool as a remix.

I've finally decided to print this out and started with the drive wheels. I am ideally wanting to print this at "O" Gauge (31.25% of uploaded model). Issue I'm having is that the wheel is hollow when slicing (Simplify3D, 0.4mm nozzle, 0.15mm layer). At the scale reduction I am using, the perimeter walls for the open areas of the wheel aren't slicing and the print isn't successful. Regardless of infill percentage I choose (even at 100%), the wheel prints hollow.

I have tried to fix the model in netfabb, tried to import the mesh into Fusion 360 and then export a new STL. I have yet to get the wheel to NOT be hollow.

I do not have Solidworks, so I am unable to attempt fixing the issue with the SLD files. If I change the scale reduction to 40%, then I can at least get the open areas to print with a perimeter wall. But, 40% does not equate to any standard gauge size.

Comments deleted.

How did you print the Drive_wheel_assembly part? It doesn't seems to be manifold and the automatic repair in Slic3r doesn't seems to be able to fix it.

This is awesome ! Once I get time, I am making this for my father for Christmas, hopefully will get it done if I start now lol.

Well, I'm at about 90% done after one year (only using a 200x200x180 build volume printer, not 24/7), but with a big size printer (CR-10. Tevo Tornado...), you can save a lot of time. Good luck ;)

how many rolls of filament did it take?

It took me about 11-12 rolls with only a couple of small parts remaining to print/re-print, but thats counting the failed/re-printed parts.

Another quick question for all who finished assembling the model. Where do the stoker pipes go? I printed them all out, and the stoker support, but can't find it in the complete 3d model.

Hey everyone! After a long-long time, I finally finished the bigger parts, so now I'm starting on the pipes, and linkages. I came across the stoker pipes, but I cannot seem to find them anywhere in the complete 3D model. Could anyone tell me, where sould I attach them, or if I even need to print them? Thanks

Hi Paul Fischer,

Yesterday April 19 , 2017 Mr Benoff started his project of publishing the print-files for the BigBoy tenderparts.
As you know I printer in 2014 your BigBoy already and waited all that time for the (your) tender files.
Would very much appreciated to apply your stl files (most ones should be ready as you commented previously) as I want to print the tender in your original scale.
Like to hear from you.
Wim de Groot, The Netherlands

Thank you for tinforming me.
I downloaded the files.
Wim de Groot

I am guessing this project is a dead end with the tender never to see the light of day sadly.

search union pacific

Hi, i am going to print this amazing model. My complements for the design!
I cannot find what infill percentage should be used, can you give me an idea?

I am printing this awesome model right now, be prepared for a lot of printing ;) I may be doing it wrong, but I'm using 15-25% infill. 15% for decorative (non structural) pieces, and 25% for structural (wheels, axles, frame) pieces, and 2-3 shell layers. I can only hope, I'm doing it right, and the locomotive won't crumble under it's own weight.

Oh, and one more thing. If you look at the files, you'll see that for most, like the wheels, the boiler, the cab, and so on, there isn't that much infill to matter, those are thin pieces. The only big chunky parts that would much infill, is the engine frame parts, and the axles at most. So yeah, I'm pretty confident ,that 25% should be sufficient.

Thank you for the information!
You are right, my worries were for the engine frame parts and axles, but i think you made a good decision.
I will do the same, we will only know when we are ready if the choice was right.

Just burnt my control board printing this incredible model. I ordered a mks gen 1.4 with smc2100 stepper drivers so i have already a delay.
Good luck printing the big boy!

Hey guys, started this huge project a month ago. Great model, but need some help. On the trailing truck, is there a sleeve, or bearing that goes on the axle? It seems it's smaller than the hole on the frame. Also its thicker than the hole on the 42 inch wheel? Can you tell me how the parts go together? Looked at the pic, but still ...

Never mind, got it, I need to print axle bearings.

Excellent model! Kudos to the person who designed it and made it available for download. I'm printing this on a slightly reduced scale (66.37%) to make a 2-1/2" gauge model, as part of a project to make a live steam version in that size. I have the UPHS drawings, printing out this model helps me to visualize some of the more complicated parts of those drawings. I'm printing with a Malyan 150 (an i3 clone), and all the parts seem fit the print area on the reduced scale, so I'm cracking on with it :-) It would be nice if the tender were made available too, but I can always draw that up myself, eventually - I have to do a crash course on 3d modelling first, LOL

Has there been any progress with the tender? (Fingers crossed)

search union pacific

what scale is this train? and if you know how much filament does it use?

If you print it at 50% scale it's very close to "G" gauge.

Hi Paul,
I'm not sure if I should print a model of this train on my Up! Mini 3D printer? As the name suggests, the printer only has a bed size of 100mm x 100mm and a print resolution of 0.2mm. Before I consider printing it, I would like to know what the largest piece is (so I can scale all the other pieces accordingly) and what the most detailed piece is, as my printer has some trouble printing detail if it's not on a flat surface. If I can test print these two pieces I can determine whether I should print it. I do know that it's a hard print and that it will use a lot of plastic but if I can do it I think it's worth a shot.

Hi Paul,

how is the 25-C Centipede Tender doing so far? :) Hope all is running smooth and you can finish the Beast soon.


May be I have a mistake but in one your replies you wrote that in GrabCad library there is smaller scale of this very nice work
I download the both file ( from Thingverse and grabcode ) but when I try to compare size of some part before printing it seems to be the same .
Do i have any mistake in my understanding ??
Regards Doron

how much filament does it take?

Well it's still not done and 2016

The instructions reference drawings. Where can they be found?

Hi Speedy,

here, scroll down to the UP 4-8-8-4 Big Boy Drawing Sets: http://www.livesteamlocomotives.com/union_pacific_drawings.html

and in the Union Pacific Shop, here: http://shop.uphs.org/unionp02.html

But I have no Idea which one from both is more detailed...


Hello, I am in the 1/8th scale railroad hobby and we are building one of these fully working in 1/8 scale. I understand you are working on a tender and if so any idea when it will be done? We plan on actually printing the parts to our scale and casting them in steel. (at least most of the parts we can use i.e. wheels, tires, rods, ect.....) This is a great model i love it! Im planning on printing it myself after im done with this 1/8 scale passenger car truck. Thanks!

I'm currently working on preparing the water tank / hopper to be printed on a Z18. I have the frame and about 75% of the suspension pieces done. If all goes as planned...I will have the tender up by the end of January.

I really love this project. I can't thank you enough for posting this model Paul! I am building a "full scale" version and I'm about 200 hours into it ;0) I really look forward to the tender files. Thanks again for your generous contribution!!!

Where did you get your plans?

I plans came from the Union Pacific Historical Society. I was working from many of the original blueprints. Other reference material included lots of photos from the web.

Hi. I have a question. Did you design this at 1:1 scale or did you design it at 1/15 scale?

Comments deleted.

My original design was at 1:1 scale. I was working from copies of original Union Pacific blueprints for the model (including the tender). It was a lot easier to just have Solidworks scale the parts down instead of scaling the dimension as I was drawing it. When I got to printing...some of the pieces such as the boiler walls had to be thickened up for strength.

I'm working on getting the tender printed. So hopefully in the next month or so I will have the scaled files available for that as well.....which at 1/15 scale....will put the entire Big Boy over 10ft long!!

ok, but are the files 1:1 scale. Cause I want to print one in HO scale

Jon, if you want to change the scale of this model, you will have to go over to GrabCad where I released the scaled Solidworks part files. Once you have those drawings you can go in and change the scale from 1/15 to HO.

WOWZER, gorgeous loco, im gonna have to try and scale her down to fit in with my 28mm scale tabletop steampunk/horror miniatures game im playing, and this is EXACTLY what ive been looking for, i'll post pics once shes scaled and printed :)

Cool....can't wait to see the pictures!

I wish this wasn't so big! I would love it if it was Lego scale!

Check out GrabCad now....the Solidworks part files for this project are now available

LOL....I had to make it big!! It was impress the MAKERBOT CEO !!!

The hard part was scaling it down to the size it is.....my original drawings for the "Big Boy" were at full scale!!!
Hopefully in the next couple of weeks...you will be able to get your hands on the Solidworks parts when I upload those files to GRABCAD!!

Looking forward to the tender and the solidworks files. This is a wonderful body of work.

The Solidworks files for the locomotive are now up on GrabCad. The tender files will follow as soon as I get done printing it.!!!

Hey there! Thanks for posting the files to GrabCAD! You've inspired me to try my own hand at making a Pere Marquette 1225 2-8-4!

If you have any pointers or good resources for diagrams, please feel free to share them ;)

Awesome model!

Thanks for drawing this out. I'm going to try to build this with a running chassis under it in 1/20.3 scale. How the tender coming along???

I'm currently printing the tender.....working out some design changes.

The tender will be up here in the next couple of months.
I'm currently finishing up another MASSIVE project...and I will have that posted in the next couple of weeks.

what scale of track? O? HO? Lego? N?

I printed the whole locomotive at 1/15 scale. It was just size I chose that would allow me to maximize the printer.

Yep where is the tender (printing 50% 90% finished loco)

the tender is in progress....working out the best way to print it.

It will be up in the next couple of months.
I'm finishing up another massive project....and that will be posted in the next couple of weeks!!

if there is something new in the subject of the tender ? when there is a chance that it will be available ?

MAV33....I'm hoping to get the tender printed...and the STL files uploaded here and the Solidworks assembly uploaded to GRABCAD in the next couple of months. I'm currently putting the finishing touches on another EPIC project...one that makes this locomotive build look like child's play. So in the next couple of weeks....look for another project from me!!!!

Any chance I can get the Solidworks files or iges files for the parts? I'm building live steam locomotives with my dad. He was a fireman and a hostler on the big boys. Your drawings would give me a huge leg up on a working eighth scale working loco.

Alames....I'm hoping in the next couple of weeks to get the Solidworks files loaded up on GRABCAD. When I get done printing the tender that goes with this locomotive...I will have that posted here and on GRABCAD as well.

I've looked through the comments and haven't seen this mentioned so I shall. In the build instructions you specify that all the wheels on the engine frame should be attached with their "(counter weights down)". Surely only the wheels on one side should be like this with the wheels on the other side offset by 90deg?

The wheels on opposite ends of axles should be quartered, 90 degrees apart. This is so the loco can start no matter where it stopped, even with a piston fully extended.
Union Pacific had right hand lead. The right hand wheels are 90 degrees ahead of the left.

J cant find 38 inch weel in file - where is it ?

It should be a 36 inch wheel ...must have been a typo

In the mean time I have put the Big Boy on printed rail-sections, but there are a few questions left:
1) Your model has nice steps on the back side , but STL files are not listed.
2) What is the right location of placing the "Stoker pipe" and what is its function?
3) Where and how to mount the "Front step bracket"?
4) Would like to print and build the "coal-truck" as well . Any chance in the future?
Thanks for all your work in providing this nice Big Boy project. It took quite whatof my time, but I enjoyed it very much.
Looking forward to your next project your are working on.
Wim de Groot

Wim ....the steps are actually the steps off the tender....yes the tender will be online soon. I'm putting the finishing touches on my other EPIC project and home to have it posted within a couple of weeks. I will find the step STL files and get them posted.

The stoker pipe is the located under the firebox above the frame. It is the way the coal from the tender is automatically fed into the firebox. You can wait till attaching the tender to place that so it lines up with the rest of the pipping from the tender.

The coal truck( tender) is on its way...I'm printing it out now....I hope to have it up soon.

When you see the next project...it's going to make this Locomotive build look like child's play!!

Sorry I didn't get back to you sooner. I haven't checked back in a while on account of spending so much time on the new project.
Per your questions.
1) I will forward the parts to the Web Manager to get the parts posted
2) The Stoker Pipe could be omitted for now. It is the pipe that transfers the coal from the tender. The proper placement of the part will be determined when the Tender Drawings are available...hopefully later this year.
3) The Front Step Bracket attaches to middle of the underside of the Front Step Plate and to the vertical surface of the Front Engine right behind the Radiator Core.
4) The full scale Tender drawings are done. I have to scale the drawings down and cut them up to fit both the Rep2 and Z18 printers. The Tender will hopefully be printed and drawings available by the end of the year.
The next project is going to be a lot involved. As it stands it will be around 2000 pieces!! Stay Tuned!!!

Thanks for enjoying this project, and thanks for the compliments! Makerbot and I appreciate them!


Hi Paul,

The year has ended almost, so I come back to you with the questions:
1) When do you plan to publish the Tender STL files?
I am out of "great" 3D-projects and would very much appreciate to extend and finish my Big Boy with that coal-truck.

2) I stayed tuned to learn your new project with around 2000 pieces.
Some info on the object would be very much appreciated.


Wim de Groot
The Netherlands

J cant find 38 inch weel in file - where is it ?
and when we will see the release tender

Hi Mav33.

There is no 38 inch wheels in this build. If it's called out in the assembly procedure it must be a typo.
The tender will be available after I complete my current project for Makerbot. I was hoping to have the tender ready by the end of the year, but the current project is taking longer than expected.


Paul, this is an excellent model. How can I get the model into SketchUp? Anyway you can upload a file type to do so? I didn't have any luck with converting the e-file. Thanks!

Thanks!! Sorry....I don't have too much experience with SketchUp.
Currently I'm working on another...larger and more complex project that I'm working on between 4 - 6 hours a night, after my full time day job. So I'm not going to be able to play with SketchUp at this time.

Great Job. I just downloaded the files and looking to do this one. My question is now what material have you worked with. Did you use ABS or PLA. I will be happy to see the tender as well. Im thinking of printing this with laser sintering out of metal would be great. Thanks for the info.

Sorry for the delay in getting back to you....I've been sooooo busy working on the next project!!!
I used Black PLA for all the parts of this model. Ugh....sorry to hear that you "only" have the 2X!!! LOL.
I designed the parts to work with the REP 2. with it's 6x6x12 build area. If you let me know which parts you are having problems with, I could mod them to work with the 2X and send them directly to you.

Hi Paul
Thanks for the awnsers. I just figured out that when I print it as Sn00zerman sayd on 92% it will fit on it.
I just have one wish I would like to print the Rail like this thing 38609 can you separate the rail so I have the rails as a standalone and then iI can use the oder one as support? Becouse I would like to Print the wood in brown and the rails in silver. Thanks for your help and keep on doing this great stuff. If Makerbot ever comes to Switzerland as a stand alone company I will work there.
Greetings Roger

I've uploaded the files you requested to the web site manager. The files should be available next week.

Hi Paul
Thanks for your effort. I got a last question. Is it possible to get a STP or STEP file of the complete drawing that you uploaded I do not have Solidwork only Autodesk.

Is there a possibility to get the Solidworks assembly or an E-drawings file ?
It's hard to see the final assembly on that one huge STL file.
(for example, the springs, I don't know where the regular ones go, and the mirrored ones, and there are lots of other parts not so easily identified on this STL, a solidworks assembly would make it easy to identify parts)
Started printing this weekend. (I first had to finish another project, printing an extra printer)
printing at 92%, because this is the exact scale for 3 1/2" locomotives :-)
One printer now dedicated for this print-job for the comming months, and a second printer for small "inbetween/other" projects.
thank you,

I've forwarded a copy of the e-drawing of the locomotive assembly to the site administrator.

Hi Paul,
I just downloaded the Edrawings assembly, awesome :-) This is what I needed !
I'm surel lots of other users will also find this usefull.
Already a box full of parts, now I can already start assembling sub-structures :-)
Keep up the good work, and I'm hoping you get the tender finished by the end of the year ...
P.S. You should open a paypal account, to accept donations !
best regards from Belgium,

Glad I could help!! I'll have to remember to upload the E-drawings file on the next project!
It will need it...since the next project is going to make this build look easy!!! LOL
Thanks....If all goes well..the tender will be printed near the end of the summer. The full scale drawings are done...I have to scale them down and mod them to print on a Rep2 printer.

Hi Paul,
Looking forward for the tender :-) Already printed about 200 pieces of the BigBoy. (I started with the largest pieces first, printing 24h/24h - 7d/week) I think I will finish printing somewhere by the end of june.
I have 2 printers, but currently only printing on one printer. (other printer is also fully occupied, with smaller projects)
I'm also looking forward your next major "big" project, can you tell me what "colors" I will need ? (just to be sure to order them in time, lol)
good luck,
best regards from Belgium,

Kris, The next project will need about 7 colors. Unfortunately....I have to keep the exact colors under wraps along with the project. Sorry.

You talk about using rafts/supports when printing. I understand why to use it, but not how to use/implement it - please help. Apologies, I am a newbie!

Hi if you a newbie as you say i would try something else to get experience before you try making this as you may struggle, but with raft/support depending on your software there is normal a tickbox to use raft and options of what type of support to use hope this helps you also with the drawings refer to pictures of frontend/truck etc at top of this page

Fantastic job!!! Where do I get the drawings referred to in the instructions?

I have tried to open the files, they all come back certificate of trust has expired. Is there a way to fix this? Or a way to get around it?

Would you post a fully assembled STL file?

The complete locomotive STL is uploaded now. You have to scroll all the way down to the bottom of the list of files to find
It's quite large...it's a 168 Meg file!!

3/4 finished at 50% looking very nice. as it is scaled down some detail is lost now i am starting to think about the cabinet size it will be put in will you be publishing the tender for the loco? working out length of cabinet. now my wife wants me to 3d print a bridge also to put loco on as part of the display and going to put arduino in to play sounds so my grandson can press buttons and plays sounds and lights work etc.. many thanks

Thanks!! Sounds Great!!! I hope you will post some pictures when you get your project finished!!
You might want to leave some extra room.....I'm hoping to have the tender printed by the end of the year!!

The full stl, would that need to be printed with supports?

Would love to print the full thing one day, but one must start small

Yes...it definitely would need supports.

Fantastic.... the time you must of spent on this project. i have always want a loco in cabinet on wall and model locos never met the mark but now i have 3d printer Cool. 50% scale 0.2 print have not the time or money 100% scale lol question stuck on rear engine assembly any pictures like front?

Thanks!!! I've forwarded some pics of the rear frame, I hope they help.

I am making good progress in printing the locomotive 50% scale. One question I have. The main axle is bigger in diameter the the axle 2 but I can't find the spring sets with a bigger hole fitting the main axle. Am I wrong? Any solution? Thanks

and how did you get on with netfab resize

fabulous. Best find for a long time.

Jack,..no you're not wrong...I used the same spring set for all the main wheels. I just bored out the hole in the spring set to fit the main axle.

What is the weight?

The weight is between 25 and 30 pounds.

Very nice loco very Cool

If a part is to big for your printer, what you can do is make a 50% part, redraw it in 2 halves at full size from measurements of the small part and print these two halves and glue together, bingo!!

If a part is to big i would add part in netfab basic and cut part in half then export both parts and print both halfs parts then glue together

Thanks for the info, I will try it out.

Folks, what size of the biggest part? Is it possible to print all parts on printer with work area 200x200x200?

Unfortunately, some of the parts, such as sections of the frame, and Main Rod, are over 10.5 inches long. It was designed to fit the build area of a Replicator 2.

Amazing and fantastic work! I am tempted to print it as a gift, but that is alot of work. Maybe I am giving a kit......

HOLY MOLY! I am super impressed.

I am totally dumbstruck. This is awesome. I am printing this at 95% on a UP! desk printer and so far all is well. The front engine truck is almost finished.
Reading about curling problems, I solved it by making an enclosure around the printer from perspex so no draft can upset the printing. Since I have done that my warping problems have disappeared. It is important to wait till all is at temperature of about 100 C if you use ABS. For PLA it is about 60 C. I have painted the printer plate with green heat sensitive paint and that works really good.

Do you have any problems with parts being too big? My afinia (basically an UP! Plus) has too small a work area for some of the boiler sections

I know. Turn them 45 degrees and reduce to 95% and you can do it.

Started the first parts (front engine parts). They look amazing! Just needed to scale it 70% to make it fit my Printer, but still great. When the front part with the wheels is done, I'll post it, but it will take a lot of hours of printing, even in 70 percent (PLA/0.2 layer height).

This is totally amazing! Thanks for sharing the pics and STL files.

EPIC might make a smaller one...

how many kg's of plastic did it use?

enough said

I've run out of superlatives to describe how impressive a project and how magnanimous a gesture your sharing it really is! It's something on this order that everyone who uses a Replicator dreams of creating, but I have to agree with another commentator who said "it will be a loooooong time before anyone hits the "I Made One!' button". Absolutely inspiring!

I hope that it does inspire the community! The tender will be added in the near future.
I will be looking forward to someone can say "I Made One" also. I definitely was a challenge to create and make it so it will work with the Replicator 2. After my next project, I will redesign it so it will work with the Z18, so it has less pieces and easier to assemble.

btw, Union Pacific Big Boy 4014 will be restored to fully working condition, by Union Pacific Steam program.
in fact, it was moved from Pomona, California January of 2014, and it is now at West Colton Yard.
eventually moved to Cheyenne, Wyoming for restoration.

Thanks for the reply. One last question for now, can you tell me which solidworks you purchased. It looks as though you can get a Student version. Seeing that I am new at this can you tell me exactly which version of solidworks and the approximate price for it. Again thanks so much and now I'm off to check out the tank you did.

I'm actually using the full version of Solidworks 2013. I have used the student versions in the past. The only difference I could see between them is that the Student version "watermark's" the digital file to say it was made on a student version and any print-outs say that as well. Also Student version stop working after 1 year. Full versions run about $2300 and a student version about $150.

Hello. I just wanted to say that you are truly gifted. I build and fly Rc jets, helicopters and other various items. I just decided to get into 3D printing and pre-ordered the 5th Gen Makerbot (Which should have been sitting on my desk as I type; however it seems as though some "tweaking" was needed) Well I have used Autodesk123d design, I guess because it was the first one I saw and started using. I see that you use Solidworks & I see they have a STUDENT version, what would your suggestion be on how I should proceed. This will be something I will continue to use and would like a 3D software program I can both use and grow into as I learn. Again you are an Artist and for you to share something you put so much effort, time and skill into so readily, shows the character of person you are.....thanks so much, Ken.B

Thanks for all the compliments !
I would highly recommend getting Solidworks!! You definitely will not regret it.
I've used AutoCad Inventor, AutoCad, Pro/E, CadKey, SolidEdge.They all have their strengths and weakness, but Solidworks is a lot more intuitive and easier to use. It is a very powerful program when you want to go beyond the basics. You will pick it up very quickly.
If you have read the article on MakerBot's Blog...there is a link to my GrabCad Tiger tank model...you could download that model to play with, to see how I did some things in Solidworks.
Enjoy your printer when you get it!!!


Esta maravilloso ... gran trabajo ...

Thats a nice BIG print 1000+ hours wahooo wowsers, awesome someday I might print up one.. making it a smaller print would loose alot of detail, imho I would print it full size for the Mantel for the Fireplace..
Most Awesome Pice of work on this site IMHO... awesome stuff.. yep yep..

HOLY! THAT IS A WORK OF ART!!! If its possible to make a miniature version I’d do it. Nice addition to my desk or something!

Unfortunately...it was designed for the size I printed it. Some of the parts will not print any smaller and a lot of detail would be lost.
If you want to try it smaller....try printing some of the really small linkage parts, such as the "Union Link" that is one of the smallest pieces.

Wow! this will really inspire others. Well done!

Nice work! I doubt that anyone has as much experience as you do with running a Rep 2! Is there any advice that you can offer us newbies? Did you print on blue tape on the stock build plate? Anything customized on the printer? Thanks!

When I started this project....I was a newbie too!!! LOL. The blue painters tape works.....3M double-sided tape really works...but takes time to set up the next build.
The one thing I did find is...keep the printer in a fairly warm area when printing. Curling will happen more often when the room temp is low. I was printing in my basement...during the warmer months I didn't have much curling ( Room temp about 70 degrees). When it's got colder in the fall/ winter ( room temp at or below 60) I had a lot of curling even with the double sided tape.
As for customizing...I didn't need to. There are some items on Thingiverse that could be used to help printing...but I never tried them.

Yep, I've been suspicious that my cold room has been the cause of much of my curling. I'm curious about the 3M double-sided tape. They sell many different products in that range. Do you happen to recall which product number you used? Thanks!

Off hand...i don't remember what the product number is....but I will check when I get to work on Monday.

Super, thanks!

I used the 3M 401M 2in wide tape. It's pricey,,,but it really came in handy.

So our printer curls and messes up a lot, and now that I think about it, the room it's in is perpetually cold! I'll make sure to mention this to our mentor, thanks!

Awesome print!

You left out one important stat, though. How many kilos of filament did you use? (Alternately, how much does the finished model weigh?)

I used approximately 16 spools of the 1Kg True Black filament. The model weighs in between 25-30 pounds.

I get a feeling of accomplishment when I spend a day or two perfecting a simple one inch coupling...but this...this is truly an awe inspiring piece. Outstanding job! It goes to show that our community of artists, inventors, engineers and tinkerers have really limitless capabilities. A community I'm proud to be a part of. I use examples just like this when I try to explain to others when they ask what the lump of gears and belts on my desk can do. Well done Sir!

Thank you so much!! I'm glad that MakerBot has posted this project.

As you could see, this was a HUGH project to be completed by one person...from design..to print(on one printer)...to assembly, So...I'm looking forward to the community printing this out for themselves. I'm looking forward to the feedback( both good and bad) on what works...and what needs improvement.

ahh must be nice to have tonnes of machines at your disposal... lol that would have killed my printer

Sorry...I didn't have access to tonnes of machines. I printed this on ONE Replicator 2.

Did you have to replace any parts on the replicator during or after the 1000 hours of print time? As of today I have 325 print hours on my replicator 2 ( purchased it Jan 7th this year) So just wondering.. Thanks in advance.. Jerry

Jerry, The only part I had to replace was the cable to the X-axis motor. It had flexed and broke near the motor. You are well beyond were mine broke..about 250 hours. I know that problem was addressed and some revisions were made to the Rep2's. My machine was from March of 2013. But if you do start getting some offset printing...like about 1/4 inch off in the X-axis...that is the cable. Paul

Whow what a nice object, compliments to you.

That's inspiring! Is it designed for a certain gauge or just scaled to be as big as possible on a Replicator? Next time I hope MBI lend you a small battery of printers so that you don't need to baby-sit a single machine for 1000 hours (42 days / 6 weeks)!

Yes it is designed to be printed on the Replicator 2 with the 6"H x 6"D x 11"W build area. I now have 2 Rep2's so I can get 2x as much done!!

I will be redesigning the model to work with the Z18 printer as soon as I get a chance.. This will significantly reduce the number of parts needed to be glued together(eg. the frames and the boiler sections)

FABULOUS and congratulations on such a wonderful project, would it be possible to have a drawing or picture of all the modules as they fit together in the downloads file, even a wireframe or solid drawing from your solidworks drawings. I have started some test prints at a smaller scale to suit my garden railway scale, though I did read your note earlier about it being it being designed for big printing, I don't know if it could live with my other Loco's.

We've uploaded Paul's drawings to the gallery :)

I have been working with the people at Thingiverse to get some pictures of solidworks drawings added to a rough instruction set, to be added to the web page/ download.

I have to ask, which part or parts would be the most demanding to print? For example, in terms of details and resolution, or bridging for example. Just wondering where to start to test things.

Resolution-wise...I printed the entire model in the Standard resolution. Some of the smaller Linkage parts such as the "Union Link" or "Combination Lever" or "Radius Bar" would benefit from using the higher resolution since they are so small. Another part that would be a good place to start testing is the "Reverse Gear Motor". This part has a lot of very fine detail to it.

When I was test printing... one of the Main Drive Wheels took about 5 hours to print on Standard....9+ hours to print in High!!!

Did you use any rafts when printing for example the Rear Gear Motor NO STAND OFF ?

I generally used rafts all the time. I had issues with curling, but found out that the room temperature had a lot to do with it. The warmer the room...less curling. Some of the bigger pieces, such as the Cab wall and Boiler sections I didn't need rafts.
The Gear Motor most definitely needs the support material. The linkage rods also definitely need rafts/supports.

Awesome,, that what I was thinking.. Let the printing begin LOL

I'll never complain about 20 hour print again! This is awesome.

I'm glad i only had to print it in the Standard Resolution!!! It most likely would have been over 2000 hours to print in High Res!!

my kids would be grown

It'll be a looooong time before anyone hits the "I Made One" button.
+1 cool.

3 people already clicked on the like button.

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amazing !!! great .. like it very much .. thanks !!!!

"Not a project for the faint of heart ..", I'll say!

Unbelievable, I cannot fathom a design and build of this complexity.

Great work!

Nice job! Does it roll on the track? Could it be motorized?

This is just a static model for display. It would take a lot of redesign to make it operational.

Not only jaw-dropping from a technical perspective, but the fact that you are sharing this freely with the community makes it hands down the most impressive project on Thingiverse.

Thanks! I am humbled by your high opinion of this project.

It will be even more impressive when I can get at chance to print the Tender to go with the locomotive. I have the full scale drawings done...just have to scale them down and break up the parts to fit on the Replicator 2.

Got to see this in person at MakerBot HQ. It is really, really impressive. Nicely done Paul!

You can use Loctite Super Glue or Zap-a-Gap Medium CA+ (you can also use Zip Kicker CA Accelerator with it).

Can you motorize it for a garden railway?

This is just a static model for display. It would take a lot of redesign to make it operational.

Do you have a link for the specific glue to use?

Thanks for the info.. AWESOME design and print.. WOW... I ordered some black rolls of Makerbot Black PLA today..

Very Kool.. this is on my list to print

As a train-enthousiast, I'm really impressed by this mega-project ! Kudos my friend !

I have one unanswered question: what is the biggest piece "volume" ?
(I mean, what is the largest needed X/Y/Z ? I have a Velleman K8200, with max. 200 x 200 x 200 mm build volume, will this be enough ?)

Thanks for the compliments.!!
Sorry...the biggest pieces top out around 10.5 inches long. Large sections of the Frames and some of the linkage were designed with the build area of the Replicator 2 in mind.

Thank you for the files. I always loved the big boy. A 200x200mm print area should have about 11 inch if you go dangle,

Great. Compliments are earned, definitely!

Maybe a nice idea to have this "crowd-printed" by a group of volunteers. 1000 people only need on hour each :-)
If some train museum organizes the "crowd-print", I will offer 5 hours on my Orca for free, including the PLA.

Are parts snap-fit, or is 6 litres of cyanoacrilate needed as well ?


Thomas, It took about 2 2oz bottles of CA to glue it together. My next project will be a combination of glue and Snap-fit parts.

i am curious how much abs did it take to make?

It was made with using only PLA filament. I used approximately 16 of the 1Kg spools to print.

="thingiverse-1add8d786863a7d547b73c2657406d19:disqus" href="http://disqus.com/thingiverse-1add8d786863a7d547b73c2657406d19/DannyVD I have drawn the tender with the intention of printing for MakerBot, but I ran out of time before the delivery date. The tender will be printed at some future time.....I'm working on another AMAZING project at time for MakerBot....STAY TUNED!!!

This is mindblowingly amazing, I am stunned. Is there any plans to do other models? I suggest the Mallard next!


Thanks for the idea...but right now I'm off on another "Mindblowing" project!! Stay Tuned !!!

Wow. I had a huge fascination for steam locomotives when I was a kid - and I still get a thrill seeing them, real or in scale models. This is one really amazing print! Love it!

HAS this been printed? Oh... let me guess... at MBI in Brooklyn!

Yes...the "Big Boy' has been printed....it is at MakerBot in Brooklyn. But I printed it in Maryland...on a single Replicator 2 machine. It took about 1000 hours to print...after more that 700 hours to draw it.

When did you start the project? Deigning? Printing?

Very impressive!


I started designing and printing the model in April 2013.
The drawings were completed in November 2013.
The printing was completed about the first week of December 2013.

Can't wait to see what you are up to next!! All the best

Will the tender (coal wagon) also be build/designed? Really impressive model.

I have drawn the tender with the intention of printing for MakerBot, but I ran out of time before the delivery date. The tender will be printed at some future time.....I'm working on another AMAZING project at time for MakerBot....STAY TUNED!!!

Please share the tender. I really think this is great project, would be a shame if it lacks a tender. It's even bigger then my Smit Rotterdam (wood build) in scale 1:50 (150cm / 5 feet long). I'm trying to get it to fit my printer (prusa). 1000 hours of printing time. WOW, that's more then 41 day of contious printing, RESPECT.

Danny...Unfortunately right now, I cannot release the Tender. When I get it printed and the drawings to Makerbot, they will release it.

Maybe late 2014 I will get a chance to print the Tender. Right now, I'm working on another massive model...STAY TUNED!!!

You MUST somehow release the tender! Even if it just becomes a community project to finish it and add it on. A large locomotive without a tender... well that's just not done! ;)

I know....my original full scale Solidworks model has the tender. I was only contracted to do the engine, but I had drawn the tender and was going to print if time allowed. The deadline came up quick, so the tender is going to be a smaller side project with MakerBot.
I will get back to the Tender as soon as my current (and MORE MASSIVE) project is complete.!!
Trust me....I want to see it complete too!!

More massive... hummm... as in maybe of TITANIC proportions? Personally, I would prefer the Bismark, but I'm not fussy. ;)
I will make a test print of the Reverse Gear Motor next.

Ha ha ha.

Seriously, holy smokes! I'm wondering how well this would print scaled down to being 1-2 feet long instead of 6.

Unfortunately the model won't print properly that small. I designed the parts to be printed that big.

Holy Cats! At what scale was this printed?

The model was printed at approximately 1/15th scale.