# 3d printing a 1:22.5 scale locomotive



## peter_m (Aug 10, 2014)

Hi, my name is Peter and I'm new here, as you can read in this thread:
http://forums.mylargescale.com/33-new-members-forum/38986-another-hi-holland.html

Last year I bought a 3d printer and beside other projects I built a locomotive which is almost completely 3d-printed. I was asked to share the story of how I designed and build it.
Please keep in mind that English is not my first language so please excuse me if I use some strange sentence structure 
Also feel free to ask for more background information about the 3d modelling and or 3d printing. I make 3d drawings as a profession so what may seem clear to me might not be to yours. I might switch a bit to fast between my story, some information about printing, modelling and back to my story again, so if this confuses you just let me know!
I'm still learning 3d printing and this is visible in some of the parts of the locomotive.
Also keep in mind that I still know very little about locomotives, so I kind of had to guess what some of the parts were. The plumbing is just a bit of my imagination 

Well, here we go!

As I told in my introduction I started playing with my LGB train when I was a kid. As I grew older i dreamed of the idea to build a permanent layout, rather than using it as not much more than a toy. Of course I needed a lot of trains on that future railway. My biggest problem at that age was that a new locomotive would cost me about one year income. And by the time I would have saved enough money I had already 10 other things in mind to do with that money. For that reason I started thinking about building my own trains. My dad had a nice workshop so I had access to a soldering iron and some brass sheets. I asked my grandpa to make some wheels on his lathe that would fit lego axles. My plan was to make Mogul loc as i had a side view in an LGB catalog. I wanted to make power block from some lego gears and motor and solder the body. 
No of course I didn´t start with something small like a flat field railway car. A real riding locomotive was much cooler so I first needed this and later on I would make some cars..
Long story short, it was no success. 

Nevertheless I always kept dreaming of building my own "machines". No matter in which form. A few years ago I heard about consumer 3d printers becoming quite affordable and knew I had to have one. About one year ago I bought an Ultimaker Original kit. About 4 long evenings were used to assemble the kit (fortunately with help from my wife) and some more to fine tune it. When I got it running I was surprised by the quality of the prints and immediately started thinking about what to make with it.
It didn't took long to start dreaming about building my own trains again..
Only a little bit smarter than years ago I first designed this 4 axle flat car:
http://www.thingiverse.com/thing:183820

It's a simple design but the floor was quite difficult to print. It is a large flat area that tends to warp during printing. I think this is a good moment to start about the basics of 3d printing.
If I do, please excuse me for giving you incomplete or half right information, I'm just telling you what I know about it. Also I've seen that there have been articles on this site about 3d printing, so some information may be old news.


3d printers are machines that build objects by placing thin layers of material onto each other. These are normally plastics bus can also be powders which solidify or even layers of paper. The consumer printers where many people are so excited about, mostly use a plastic wire or filament. This can be made out of many plastics but ABS and PLA are most common. I usualy use PLA for a number of reasons. I find it more easy to print with than ABS. It has a nice shiny finish and is quite strong (but a bit less flexible than ABS). If you print with ABS you need a heated build plate, which I tell you more about later on. The Ultimaker Original still doesn't come with a heated build plate so I have built one myself. However I mainly use it to improve my PLA prints rather than to print with ABS.
As said there are some drawbacks to PLA as well; It is a bit brittle compared to ABS, has a lower melting point (which for instance, could be an issue when using it in gearboxes) and I haven't got a good solvent to glue it (it should be available but I haven't tried it) so I use cyanoacrylate if I have to bond parts.

My ultimaker consists of a frame with double x- and y-axis. These are used to move the printhead by small but strong stepper motors. The printhead is mainly a 0.4mm nozzle with a heating element attached to it. Besides this it has a small fan used to cool your print during the process. On the back of the printer there is an extruder mounted that also uses a stepper motor that pushes the filament trough a bowden cable into the printhead to the nozzle. Here the filament gets hot and starts flowing out of the nozzle. By moving the x- and y-axis and pushing the filament trough the nozzle it can draw a layer on the printbed. This bed is a flat plate attached to a spindle. This spindle is connected to the 4th stepper motor and by controlling this one it moves the bed up or down (down of course during printing) so here we have our z-axis. 
There are more designs possible, for example with the printhead only moving on one axis and the printbed moving on the other two axes. A drawback to this is that your print is shaking during the whole print process and by this it might come loose from the printbed (usually when your print is almost finished). Another plus of the Ultimaker design is that by mounting as few as possible parts to the printhead it stays very lightweight so it can move very fast and thereby also print very fast. Especially in the beginning many printers had the extruder mounted on the head which made it more heavy. Ultimaker was one of, if not the first to mount the extruder loose from the head to keep it as light as possible. I think by now more and more brands come with this design.

So now when the printer starts "drawing" a layer it normally draws the perimeter, and than colours the area within, like a cross-section. When it is finished with this the z-axis spindle rotates a little bit and the bed moves down, for example 0,1mm.
Now the printhead can start over again for the next layer, drawing the perimeter and the infill but now with the cross-section perpendicular to the previous layer. 

Wow, three hours later already. I usually don't speak this much not to mention in English.. 
I hope this all sounds a bit interesting to you. If so I'll continue my story tomorrow.

ps. for those not willing to wait for the end result, I attached a photo of it


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## Jerry Barnes (Jan 2, 2008)

Looks good Peter. You seem quite skilful in something I will never try.


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## tmejia (Jan 2, 2008)

Peter,
Keep posting. I find this very interesting.

Tommy
Rio Gracie


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## Totalwrecker (Feb 26, 2009)

Welcome Peter,
Please continue, we can learn as you go.
No need to apologize for your English, we are happy that you take the time to use it.
Happy Rails,
John


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## DKRickman (Mar 25, 2008)

Jerry Barnes said:


> You seem quite skilful in something I will never try.


Why not, Jerry? It you're willing to learn something new, 3D printing might have something for you. I've started playing with some designs and products from Shapeways, and I have to say, I am impressed!


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## Stan Cedarleaf (Jan 2, 2008)

Welcome, Peter... Wonderful use of the technology available today. 

Very interesting and very nicely done..

Yes, there is no need to apologize for your use of English...


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## vsmith (Jan 2, 2008)

Its too bad the finish results still show a bit of the crudeness still latent even in state of the art printers, namely the rough texture. I have received some printed parts and they all show this, its a result of the printing process itself so there isnt much that can be done about it save alot of sanding to smooth the finish surfaces. But given where 3D printers were a couple years ago, there's been amazing progress so I expect in about 5 years the finish quality will be right up there with the best injection molding.

I have been pondering just where this technology will take us and its long term effects on hobbies like Model Railroading, I can quite easily see someone investing in a 3D printer the right CAD program (or just get files off the net) and 'print' whatever you needed for your layout. One of the biggest complaints I have always had about LS is the extremely limited selection of structures available, soon you may be able to take a photo of a building, translate it into a 3D file and print it out, same for locos and rolling stock, we are already starting to see that today.

The long term effects of this remain to be seen, not everyone is going to be able to afford a 3D printer but enough will, and how that access to an almost unlimited selection of possible models will effect how manufacturers produce their product and what (if any) new product they offer to counter the 3D market. I suspect that some manufacturers (in all scales) are very soon going to see 3D printing as the biggest threat to their bottom lines since the crash of 08.


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## Jerry Barnes (Jan 2, 2008)

Maybe the manufacturers will adapt and print their own former castings right here in the United States, making small runs of all types of trains. That could be interesting.


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## peter_m (Aug 10, 2014)

Thanks everyone for the compliments! this gives me more than enough confidence to continue my story.

A quick reaction to the last 2 replies; I have been thinking about the long term effects to this new technology as well. 

I think when you compare it to a revolution not too long ago, let’s say the personal computer, 

we are at this point still far before the introduction of the comodore 64.
Like every new technology it will bring us lots of good things but of course there will be negative effects as well. 

When 3d printing becomes available to the masses (and then I mean affordable and being able to use it without having to know what you are doing), 

it doesn't need much imagination to realize that it will start a whole new form of piracy. 

This has already started; take a closer look on thingiverse.com...
Illegal downloading of music and films concerned a relatively small group of victims but think about being able to make about everything what you see...
Fortunately (for all those manufacturers) were still far from that point, but don't underestimate how fast this could go.
I'm curious about how the industry is going to solve this.


Back to my story:
I looked at what I wrote and thought it might be a bit difficult to understand without pictures. 

So here are some photo’s of the printer:
https://imagizer.imageshack.us/v2/1037x943q90/661/vAIKeD.jpg
https://imagizer.imageshack.us/v2/1029x822q90/906/nAdDQd.jpg


Here you can see the parts I discussed yesterday. 
Well enough about the printer for now, I’ll tell you more about it as my story continues.
Let’s talk about the model.
I was looking for something not too challenging and I wanted clear photo’s of it. 

I started searching the net for narrow gauge railways when I came up to the Saxonian railway. 

They had a nice series of steam locomotives including the 1K. 

I think it looks good and I found quite a lot of large photographs including a good sideview. 

Found some dimensions so the parts were scaled to 1:22.5. 

Later I found that I must have had my scale a bit off because it looks a bit out of proportion next to my LGB Dicke… 
No very big deal, the project was mainly to see if it is possible to print a complete running loc and worry about details etc. when I build my next locomotive.
https://imagizer.imageshack.us/v2/1437x943q90/674/elHvNx.jpg


I first made a rough sketch with the main dimensions like wheelbase, spaceclaims for the motor, gearbox and so on. 

This called the packaging.
Then I searched a electronics shop for an electric motor that was not too big and had (hopefully) enough power to run the loc: 
http://www.conrad.nl/ce/nl/product/...-toerental-14850-omwmin?queryFromSuggest=true

I measured the wheels and asked my grandpa to make them in aluminum on the lathe.
By doing so, the motor and wheels were my only “hard” dimensions. 

Everything else could be fit around this. When designing, 

I like to capture some dimensions or parts as a starting point. 

This way you have a bit of footing during the process. 

The drawback is that there is a risk you have to change your foundations. 


After I had this clear I started the modeling in Creo (former Pro-Engineer). I use this at my work so I’m happy I can use my computer there. 

Otherwise I think I would have to fall back on free software like google sketchup or something. 

Just as with 3d printing, 3d CAD is not that difficult when you get the hang of it. 

The basic principle is that you draw a section, and then extrude of revolve this to get a 3d object. 

Besides this there is an almost endless list of features like cuts, fillets and so on that you can use to modify your shape. 

This list is always growing and every new release brings new fancy features that promise you to work even quicker J
When you got the shape completely as you like it, you created a part. 

Two or more parts can be used to form an assembly. I guess this is pretty straightforward, you generally buildup your virtual assembly just like you would build the physical one. 
https://imagizer.imageshack.us/v2/541x943q90/904/zIZeeB.png


When we translate this to the locomotive I started with the chassis, then the boiler, the cabin and then all the detailing. 
This was the first version of the chassis:
https://imagizer.imageshack.us/v2/1363x775q90/540/3nXBax.png


It looked good with the drive gear quite accurate and the motor placed low and compact in the chassis. 

The chassis was one single box that would be printable in one time. 

I thought it should work well, so as soon I modeled the rest of the body far enough I started printing. 

Soon I realized that I made some mistakes. First of all I made no calculations for the gear ratio. 

When I was ready to let the motor run for the first time it immediately appeared that the ratio was too heavy. 

Besides that I didn’t use any bearings so everything had a lot of play. 

The worm axis was placed in two slots and the wheel axles were about the same. 

In fact when I ran for the first time it made such a loud noise it almost scared our cat to death.. 


So back to the drawing board …
https://imagizer.imageshack.us/v2/1465x823q90/661/1pFRQ1.jpg


In fact it took me 4 revisions before I had the chassis completely working. 

The very first one broke in half when I tried to lift it from the printbed, the second one was the one described and after those 2 more would come until it was acceptable. 


Well I think this is enough for today, again if someone has any questions of suggestions feel free to ask!


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## riderdan (Jan 2, 2014)

Thanks for the additional info, Peter.

I'm curious how much run time your printed locomotive has and how the gears are holding up. I'm just thinking PLA is rather soft for gears, but it is neat that the whole locomotive is printed, rather than just the shell.

I guess if they get worn down you can always print another set


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## peter_m (Aug 10, 2014)

The loc hasn't got much run time and the gears show a little bit wear, but I think this is mostly from testing it with too much play on the gearbox and trying to make it run when for example something was stuck and everything got locked up. When they proof to be to weak I can simply make a new set but I can also try a different material just for the gears for example ABS. I also have another plastic which is a copolyester and has like ABS a higher melting temperature and has more strength than PLA bus is easier to print than ABS. I'm going to let it run for some longer time to see how everything is holding up. 
For next projects i'm going to scale the gears up so they become even stronger


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## vsmith (Jan 2, 2008)

Great write up on the process, I think your going to find that you're to have to use metal gears and bevels on the drivetrain, plastics just dont cut it. I hadn't realized you printed the entire drivetrain (which is very impressive). I would have used a modified commercial drive block like LGB or Piko just because the reliability and durability is built right into it, but you seem to doing quite well on your own.

I think the only reason I haven't paid too much attention to these DIY 3D printer kits is that I already have more stuff than I can really use.


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## peter_m (Aug 10, 2014)

Yes I might come to the conclusion that I need metal gears but at least I want to try. 

Especially for this project I had no idea where it was going to end so I didn’t want to make a big investment. 


As said I needed to change a few things on my chassis. 

Most important the gear ration had to be lightened and the tolerances had to become tighter. 

Also I started to dislike the design of the complete chassis as a complete box with the side plating all in one piece. 
I had some bearings left from an old nitro rc car that could be used. 

Two larger ones (19-7mm dia) were used on the worm axis and 6 smaller ones (13-6mm) for the wheel axles. 

The axles themselves were also changed. In the original design they were printed but they had a bit of wobble so I had them turned in steel. 

They are six halves and slide in the gear. 

The gear has a small wall in the middle so they can never make a short circuit. 


I came up with a new design for the chassis that was now cut in half in its length. 

Also the side plates became loose parts that can be screwed to the side of the chassis. 

By doing so, the print area of the chassis became much smaller which makes it easier to print. 
Now I still had to change the gear ratio. 

I wanted to print the chassis upside up as everything was modeled to make this the easiest way. 

This meant though that I couldn’t use larger gears on the axles because they would protrude the bottom of the chassis. 

Also it would mean that my motor should be lifted up which was not easy as well because it would interfere with the bottom of the boiler. 

There was not enough room between the motor and the worm axis to arrange a few more gears. 

I thought of a concept where an axis connected to the motor would run through a hollow worm axis, powering some gears at the end (below the cabin) and these gears powering the worm axis, that in this way runs with a different speed than the inner axis 
I also imagined that this was a bit to complex.


So there was not more left than move the motor up, above the worm axis so that it would be positioned above the worm axis between the wide part if the body. 

This way I could put a small gear on the motor and a larger one on the worm axis. 



All this resulted in the 4th version of the chassis:
https://imagizer.imageshack.us/v2/1228x635q90/540/QTzQlc.png
When all the parts were printed I assembled them and again tried to let it run. 

First without wheels but soon after this with the wheels attached; 

Wow! It realy worked!


The printed chassis (still without wheels) now looked like this:
https://imagizer.imageshack.us/v2/1257x943q90/539/M6jkif.jpg


The outside was given a coat of filler and after some sanding a nice red color. 

You can see the inside doesn´t look so nice. 

This is partly as a result of the complex shape. Both halves took approximately 5 hours each to print. 

When I wanted a better finish I could reduce the layer thickness but the printing time would also become a lot longer. 

Since the outside was quite straightforward I didn´t realy bother about the inside finish and just used a rather high layer thickness. 

(I think it was 0,2mm).


Also I didn’t really like the filament color that I used. 

It wasn’t completely opaque which makes is also a bit uglier than it could have been.
So enough about the chassis for now, let’s talk a bit more about the printer again.


I mentioned that this 4th version of the chassis was easier to print because it had a smaller footprint. 

Why is this?
When you buy an Ultimaker Original the printbed is made out of an acrylic plate, about 8 mm thick. 

When you would try to print on this, your filament would just come off just as easy as you layed it down. 

So what you do to make it stick to the bed is place a layer of blue painters tape on the bed. (the one you can still remove after 2 days…) 

It appears that the PLA is really sticking on the blue tape. 

ABS however doesn’t… 
There are several ways to remove your print from the blue tape.
I often let it soak in some cleaning alcohol. 

Small parts usually just snap from the bed without alcohol. 
Now when printing you are placing a layer on the bed.
PLA prints at about 210 degrees Celsius so it’s quite hot when just layed down. After a layer is printed is starts cooling down. 

This goes quite fast, as the air around the object is much cooler and so is the printbed. 

So as it cools down it also shrinks a bit. 

Now when the next layer is placed on this shrunken layer, it is a bit wider. Again this layer also starts to shrink but by doing so, it is going to put some tension to the previous layer. 

As this continues your print may begin to warp at the edges. 

This is worse on objects with a large printing area because the difference in size between the hot and cool layer is larger. 

This effect is also enlarged by using a bigger layer height and faster printing speeds, because by doing so you use more heat.


There are some techniques to reduce the warping on large objects. 

One that I often use is to print one layer, about 15mm wider than your object. 

This helps to let the print stick better to the bed and if it still starts warping, first the skirt will warp and if you’re lucky the rest of your print doesn’t. 

After printing you can usually just snap off the part of the layer that is too wide.


This however is not a real solution to the problem, more like a patch-up
What you want is the layers not to cooldown so fast. 
This is the reason that most new printers come with a heated printbed. This is a also a flat plate but unlike the acrylic it is normally made out of glass or aluminum.
Under this plate is a heating plate that can make the printbed up to about 130 degrees Celsius (dependent of the glass-temperature of the material, 70 for PLA, 125 for ABS) 

Now when you place a layer on this hot bed it doesn’t cool down to much but stays just under the point where it is becoming softer. 

Another plus is that by using a hotbed you can print directly on your bed without the need of replacing your blue tape after every print. 

A aluminum bed like mine needs a layer of kapton tape to get the layers sticking (heat resistant tape used also in circuit boards). 

Sometimes I spray a light coat of hairspray onto the plate before printing to make it stick even more. 

Yet another plus is that the bottom of the print has a nice glossy finish as the top of the bed is also smooth.
When you have a heated bed you can also print ABS and even more plastics.



My Ultimaker Original didn’t come with a heated bed so I had to fabricate one myself. 

I bought a heating plate on a 3d printer exhibition and placed it under an 3mm aluminum plate. 

The printers electronics are partially prepared for connecting the plate. 

You still need a second power source (I used an old laptop transformer), and an NTC attached to the plate to keep the temperature constant and tunable. 

The printer has a relay to switch on the second power source and a port to connect the NTC. 

When everything is installed you have to reload the firmware of the printer and then normally it should be working as it was 


You can see some photographs in the second post that show my home built heated bed.


Well, again more to come!


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## peter_m (Aug 10, 2014)

ps. my appologies for the many enters between the lines, I type everything in Word and when i copy-paste it in the text field its comes out like this. Also when I want to edit my post all my text is gone?
<edit>


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## Semper Vaporo (Jan 2, 2008)

hee hee hee... extra space between lines just gives me extra time to absorb all the info, so no apology is necessary!

I have no idea why the text would be gone when you try to edit it. These kinds of problems really should not exist, but with computers, all bets are off.


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## chuck n (Jan 2, 2008)

Peter:

Try typing it directly into one of the two boxes provided ("post reply" or "quick reply"), rather than using MS word and cutting and pasting. It is possible that the word processing program on the site doesn't permit editing of text from other programs.

One of our IT experts should be able to clarify this.


Chuck

This is an experiment the following was typed in word and pasted in this post:

"I am typing this using MS word. I will cut and paste it into a MLS post."

I was wrong. I can edit and change the statement above. The quotes were added after editing.


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## chuck n (Jan 2, 2008)

Trying the same experiment through the Quick Reply box.

"a MLS post"

Could still edit here. Sorry I couldn't help.

Chuck


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## peter_m (Aug 10, 2014)

Hmmm, when I can change my last post but when I try to edit my longer post everything is gone?


Anyway,
Lots of pictures today!
As I was finished with the chassis I could now concentrate on something more relaxing; the body.
I say more relaxing because now I didn’t have to bother about making it work, only nice looking 
I first made a connecting plate to attach the body to the chassis:
https://imagizer.imageshack.us/v2/10...631/n9WcvA.png
Next the boiler, this later snaps to the body and is secured with two small screws.
https://imagizer.imageshack.us/v2/92...674/Kl2TXL.png
And the body:
https://imagizer.imageshack.us/v2/97...902/px2gxa.png
The cabin:
https://imagizer.imageshack.us/v2/64...537/ZfxFrx.png
printing the cabin (upside down):
https://imagizer.imageshack.us/v2/89...910/v8JRGl.jpg
You can see that I didn’t had my heated bed installed yet and to prevent it from warping I used some ducktape to tape down the first wide layer even more to the bed.
The interior, here you can clearly see that I still don’t know much about locomotives 
https://imagizer.imageshack.us/v2/69...661/FKCZNU.png
The roof:
https://imagizer.imageshack.us/v2/96...661/BuM4uv.png
The lantern. The lens was printed in a clear filament of only two layers
https://imagizer.imageshack.us/v2/63...538/LmlO0o.png
The coal container (is this the right name?).
This is a nice part, it is printed in a filament mixed with real wood fibers so no post processing was necessary!
https://imagizer.imageshack.us/v2/86...673/daoBBB.png

Next I started the assembly, that should look something like this:
https://imagizer.imageshack.us/v2/90...674/xumbUP.png
https://imagizer.imageshack.us/v2/75...674/fo8Fll.png


The boiler with the left lantern already in place. The boiler took about 16 hours to print, but I think it came out quite nice:
https://imagizer.imageshack.us/v2/89...538/oXVX6K.jpg
The boiler attached to the body, also I dry-fitted the coal container. The small seam between the boiler and body was later sealed with some strong kit.
https://imagizer.imageshack.us/v2/89...673/5vGp34.jpg
The cabin: this is screwed to the body and a small grove keeps the boiler in place. 
https://imagizer.imageshack.us/v2/89...540/46qRg0.jpg
And finally the roof was snapped into place:
https://imagizer.imageshack.us/v2/89...673/YMPw5j.jpg
Hereafter I used some electric copper wire to make some piping and sprayed on a coat of plastic primer, followed by a few coats of filler. 
https://imagizer.imageshack.us/v2/89...745/MRO63x.jpg
https://imagizer.imageshack.us/v2/89...540/daWimk.jpg
After it dried it got a black coat and when placed on the chassis it looked like this (placed on an early version of the chassis btw):
https://imagizer.imageshack.us/v2/89...673/lj0TGa.jpg
https://imagizer.imageshack.us/v2/89...908/4sXPcq.jpg


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## CliffyJ (Apr 29, 2009)

Great project Peter! You've really put your heart into the modeling and the product, and it shows. Very professional.

If your gears wear down, and before going to metal / commercial products, you might want to have your present gears printed in SLS (laser sintering), out of nylon. For example, via Shapeways.com. I've heard that such gears last quite well, for what it's worth. Also, though very expensive, they print in various metals as well.

Best regards,

Cliff


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## peter_m (Aug 10, 2014)

Thanks for the compliment Cliff!
Nylon gears might be an idea, especially when i can use my own designs.
I'm already looking forward to my next project as there are still lots of things that can be improved


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## peter_m (Aug 10, 2014)

So after a load of building pics yesterday I think it’s time to explain some more about the printing process.
When you have modeled a part you want to print you can’t just click file -> print, as you would normally do with a document that you send to your inkjet printer. 

You need to do some preprocessing. 
In your CAD software you have the option to save a file to different formats. 

Some of these are universal formats that every CAD program can read. Some well known are .DXF for 2d drawings or .STEP and .IGES for 3d models. 

Another one is .STL, also universally accepted.
When you save a 3d model to an STL file it becomes a polygon. 

You can adjust the ratio of the polygons, eg. when you chose a very low ratio the top view of a cylinder could become a six angle. 

When you chose a high ratio the line gets divided in such small parts, you can’t see them anymore.
So normally you try to convert a part so that the polygons are small enough not to be seen yet big enough to keep small sized files. 

This way they can be loaded faster in your pre-processor; the slicer.

The slicer does just what it says; it slices your 3d model in layers and writes them to a file that the printer can read. 

This file contains not only the data for the layers but all the settings needed during the printing. 

Settings like the nozzle and printbed temperature, printing speed, etc.



Here is a screenshot of Cura, the slicer that I use:
https://imagizer.imageshack.us/v2/1440x780q90/661/VxQIBw.png
Cura is free and written by the developers of Ultimaker, so it’s basically plug and play when you use an Ultimaker.


As an example I used one of the lanterns of the loc. 

You can see it’s placed in yellow on the chessboard that represents the building volume of the printer.
You can spin it to reposition it as how it has to be printed. 

At the left are several tabs to change all the print settings. 

Every time you change a setting it immediately recalculates every layer and corresponding parameters. 

There are several view modes and one is called layer. 

This one enables you to scroll through the layers that will be printed:
https://imagizer.imageshack.us/v2/1162x652q90/674/31xn06.png
Here you can see I zoomed on the object and set the layers at about halfway the lantern (at the horizontal stay) 

Now when you start printing it will start at the base, that gets a bit smaller every layer, as it is tapered. 

Now when it comes to the horizontal cylinder that holds the bulb, the layers suddenly get a lot wider, as the very bottom of a lying cylinder is almost flat. 

You can nicely see this as the image has a bit of an x-ray view.
By now every layer has a little bit of overhang; it has to be printed a bit in the air. 

This can be a problem. A bit overhang or normally no problem to but much overhang gives ugly results at the bottom of the overhang. 

This can be reduced by choosing a smaller layer thickness. By doing so, the overhang becomes smaller. 

Also small bridges in the air usually print just fine as the nozzle just draws small strings from one to the next supported area.
Now imagine printing an upside-down J; The first vertical part is no problem, just placing layers on top of each other, next you get a bit of overhang, than a bit more overhang and then it goes back down again! This is impossible ?!


Not completely..
We can solve this by printing a support structure. 

This is printed next to the other layers, under the area that needs support.
It can be something like a grid or a zig-zag pattern that usually easily snaps off your object after printing. 

Now back to the lantern.
Remember the stay at the side that attaches the lantern to the boiler. 

This is a small but completely flat area that should be printed in the air.
This is an example where you need support. 

So just select “support” from the pulldown menu in the slicer (there are some more options that are not really relevant by now).
Now it starts calculating again and draws the support under the area’s where it is needed (I scrolled a bit down through the layers so you can clearly see the x-section):
https://imagizer.imageshack.us/v2/1141x669q90/538/3Yac6v.png


You can also select “support everywhere”. 

This enables support from the base of the model but also inside the model. 

This can be necessary when there are big unsupported area’s IN your print.
This can be a bit more difficult to remove but normally also works fine. 



Now I learned that small vertical prints often don’t give to nice results so I turned my lantern on its back. 

This way it is laying nicely on the flat side of the cylinder, it can draw nice round circles when printing the cylinder and it prints a firm support for the overhang :
https://imagizer.imageshack.us/v2/1170x721q90/673/1ph7l4.png


When you have all your settings to your liking you can save the file to an sd-card. 

This file has a .GCODE extension en contains all the data needed for the printer. 

This is than loaded and your printer can start its program. 

Since you are using an sd-card, there is no connection between the pc and printer and the printer can work as stand alone. 

This can be a great plus, just imagine your pc to crash near the end of a 24 hour print… 

Well, I hope this again was an interesting explanation going a bit deeper into the theory of 3d-printing.


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## CliffyJ (Apr 29, 2009)

By the way Peter, Shapeways is in the Netherlands (and also New York).


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## Gary Armitstead (Jan 2, 2008)

Peter,

I'm very interested in your 3D printing project. I have been working on a 3D printing project as well. I want to make a scale model of the pneumatic trolley poles that were used on Pacific Electrics freight motors in the early 1920's here in Southern California.

I have taken photos of the last freight engine still in working order and have some prints of the poles. I am doing a geometry and surface (nurbs) drawing in MasterCam. Each part of the pole are on different levels so I can print the parts separately. What I'm trying to learn is how to draw the support pieces for the parts so I can do the printing. I am a retired moldmaker/die sinker, so I have experience with molds and cavities. But this is a different learning curve for 3D printing. I hope to print these parts in brass. The engine I am making this pole for is a 1/8 scale, ride on engine.

Thanks for posting with some very useful information.


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## peter_m (Aug 10, 2014)

Wow, great project!
Which filament are you planning to use for the brass parts?
I'm going to order a spool of colorfabb bronzefill. I hope I can use it for (wheatered) locomotive parts
What will be the approximate size of the model?


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## Gary Armitstead (Jan 2, 2008)

Peter,

I base of the pole, shaped like a "star", is 1 1/2 inches square (38.1 mm square). Some parts will be very large pieces. Some will be exceedingly small. I won't be printing this model myself........I will be sending the converted files to Shapeways and they can give me a quote in both resin and brass. I don't think it will be cheap. 

I have to go back through the drawing when it is completed to make sure I have "water-proof" and seamless, clean surfaces. At that time I will know how many separate parts I will need to complete the model.

.


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## peter_m (Aug 10, 2014)

Well I think this is the last part of this story, but if it’s up to me there will be much more to come.


This was the result of the work that has been done yet:
https://imagizer.imageshack.us/v2/897x673q90/742/XXbQY6.jpg


The connecting plate was mounted:
https://imagizer.imageshack.us/v2/897x673q90/745/oZecoq.jpg


As well as the motor and driving gear:
https://imagizer.imageshack.us/v2/897x673q90/742/6tZf2j.jpg
I originally designed a more accurate drive gear but it appeared a hassle already to get this timed. 

The wheels are secured with something that looks like a cam (from camshaft) with a hole in it. The cam is screwed to the axle and pushes the wheel In place. 

This was a bit weak and came loose quite easily. 

Every time this happened at one wheel the rest locked up.
Also there is quite a bit play on the worm and gears.
Because of this I didn’t even try to print the more complex drive gear.. That’s something for next time. 

So I printed the pistons, piston guide, and the pushrods. (are these the correct words?)

I also printed a part that is attached to the front of the chassis and closes it. 

Last some small parts like buffers and connectors. 

I had still to come up with a pickup for the current. 

In the chassis I prepared several possibilities for this, but the following seemed the easiest way:
https://imagizer.imageshack.us/v2/897x673q90/631/VRMciJ.jpg
It gets covered by the side plates attached to the chassis anyway. 

Left and right are just two single core copper wires bend into shape, pushing on the wheels. 

I know this is no long term solution but for now it worked.


Now finally everything could be assembled:
https://imagizer.imageshack.us/v2/897x673q90/539/tLt752.jpg
https://imagizer.imageshack.us/v2/897x673q90/674/FY0pJm.jpg
https://imagizer.imageshack.us/v2/897x673q90/910/eBcYzw.jpg


And the proof that it really works 




 
Conclusion:
I started this project to test if it was possible to build an (almost) completely 3d-printed g-scale locomotive. 

To me the project was a success, however there are some remarks.
- - Tolerances can be a problem. Especially small parts preferably have smaller tolerances which can be difficult. Holes often need to be re-drilled risking to break something. Also the gears are a problem. As some of you indicated they might be to weak to withstand long runs. Also there is a quite some play on the gears. The wormaxis is very difficult to print because the tooth are thin and warp easily. Besides that, it is hard to keep perfectly straight during printing because of the small base. 
- - Some parts could have been more detailed but aren´t because they are integrated in a larger part. (for example the boiler with smoke stack, domes etc.) 
I haven’t done this to make the assembly a bit tougher as I haven’t found a suitable glue for PLA yet. 
- - Some parts just need more work or a complete redesign. The whole idea of a completely printed gearbox looked cool to me but it takes a lot more work to get it working good. And I doubt you can get it perfect (using techniques reasonably available to consumers). 
It hasn’t discouraged me though. But next time I’ll try to get a drive block from one of the manufacturers as suggested. Also I’m going to try different materials like ABS that is stronger and can be sanded more easy to get a better finish. 



For my next project I would like to build a Baldwin 2-6-0 (with the unevenly spaced wheelbase built in the masterclass).
Although I will use a existing drive block I’m still building most of the rest myself so I need more detailed pictures. Does anyone know where I can find them? I tried google but it comes up mainly with the even spaced wheelbase versions..
Also it looks like autumn is already starting here in Holland so now I hope I have time to make plans for my garden layout.


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## Scott (Jan 29, 2008)

Peter. That is a very good result, and you can build on from that and get better. I am also planning and designing my 3d printed components for my modelling. This will augment and expand our hobby in so many positive ways.


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## peter_m (Aug 10, 2014)

Thank you, I hope that I have made you guys enthousiastic about 3d-printing!


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