Modeling and 3d printing some 34' Overtons with an Ender-3

[Woodat]

Hooray first post on these forums! But thought it'd be interesting for everyone to share this on here.

Have just started a project here in the UK to build a small American steam layout. Unfortunately finding appropriate rolling stock (as well as locomotives, buildings, etc.) has been a bit tricky, so I've elected to try and scratch build as much as I can myself.

One of my main tools is my Ender-3 FDM printer, which I can already hear everyone scream "can't do detail well enough!". Well... maybe we can squeeze a little something out of it. As exhibit A, here's a a shot of some 34' Overtons I've modeled up and painted (hastily)



Both the car and the Class-A climax were printed up by me. I'll post the details below for the settings but the short is PLA+, .2mm nozzle, and .08 layer height. It's getting good enough to do some fairly good detail, including individual bolts and some not-terrible (though obviously oversized) rivets. Wood-grain is also possible with a bit of clever layer setup (photos on that another date).

The climax is just a kato critter on a 11-107 chassis, and (as I haven't been able to source anything good yet) the bogies on the overton are some cheap chinese ones ordered from aliexpress (like 75 cents each). Needless to say they're... not ideal, but they're working for the moment (and I don't intend to pull more than 3-4 anyway). Besides the bogies the only thing not 3d printed is the handle rails on the ends, which were just simple bent brass wire.

Here's a few more photos as well of the ones I've printed out so far (2 passenger cars and one combination passenger/express mail car). I've been calling them the "school busses". If anything I think they're mostly being let down by my painting skills more than the detail on the model, but I wanted to show off the level of detail I could get with the vertical boards so they got hit with a lot of weathering wash. I'm hoping once I get my airbrush set up I can give the next batch a bit better/cleaner look. Printing on a resin printer would probably render them near-perfect, but sadly I don't have the proper space to get one of those set up just now.

Also including some photos of the 3d models to give you an idea of what they look like before printing.

[Army-Gandydancer]

Nice work. I always like seeing what people create with 3D printers.

I know buying ready to roll is not as fun as building your own. But Athearn has released their 34' Overton passenger cars. I can say that they are nicely done and some of the best rolling cars I have. I don't know if they are available in the UK though.

Here is a photo for you.

Overton train.jpg

[Heiko]

That's pretty impressive for any 3D printer, but way beyond what I expected from an FDM printer. Wow!

Heiko

[Moose2013]

@Woodat

Very nice! And, congratulations on your first post here... Let's see more please!

[badlandnp]

I agree with the above, Welcome Aboard! Very nicely done models! I don't know much about 3d printers, but that one is just fine. The cars came out great as did the climax. Well done!

[ChicagoNW]

Very nice job. Almost a perfect replica of the Roundhouse/Athearn cars. I like that you’ve added an interior. Does the combine include the wall that separates the passenger and baggage compartments?

Why did you make the platforms separate from the chassis? Could your printer have printed railings? Even if oversized?

Given the quality of the car bodies do you think you could make trucks that resemble the Shay’s or Brill as on a streetcar?

[Woodat]

Much appreciated all for the kind words
@Army-Gandydancer

The Athearns are definitely nice and I used them a lot for reference (to get a gauge of what's reasonable for n-scale)
@ChicagoNW
To answer the questions, the interior is just enough so you'd see it if gazing into the windows, and to put some people on. The Combine car does have a dividing wall (and stronger doors as I imagine those carrying things like payroll, mail,bank transfers, etc. inside). Given the scale I didn't spend an inordinate amount of time in there though.

The baseplate was made seperate to allow detail on the bottom. This eliminates the need for supports as I can then print those upside down. There's also holes for the truss rods but I was saving doing those until after I have a final set designed and painted. The tolerance is fine enough I just snap them in/out of the body without glue or screws (though there are screw holes if needed). This also allows for swapping the baseplate if/when I source or make some better bogies for them. Different bogies and couplers may be spaced differently so just reprinting the baseplate and painting it black only takes an hour, vs a day to reprint and repaint an entire new car. I also weigh these things down with some lead tape applied between the seats and the baseplate.

While I can get the printer to print the railings off (and roughly at the right scale no less) my big concern is actually just getting them off the printer's build plate without breaking them. For strength sake they'd have to be printed horizontally and separately, at which point I'm using my razor blade to scrape them off and that bends them. I'll give it a go eventually though, especially as that'd simplify making the truss rods.

I've experimented a little with trucks/bogies but not with great success yet. Since my last attempt I've uptooled a little (I've now got some axle reamers and a bunch of metal wheels/axles on the way) so eventually I'll take another swing at them as well.

---
Oh, and as for the Climax, that's also slated for a redesign. While visually it looks pretty good, it's definitely far too light to pull even 3 of these cars. I'm going to be making the base thicker to hide some weight inside, hollowing out under the boiler to add weights, filling the boiler with even more weight, and also adding some more detail underneath to put a weight compartment on the bottom. It's actually intended to pull a small rake of logging cars instead, but this was a good test at least

[Woodat]

For anyone curious to take a swing at 3d printing something this scale yourself, here's the info on my 3d printer setup:

Ender-3
Modifications:

• 0.2mm nozzle (required)
• New control board (optional but cleared up some random detail issues)
• 2nd Z-axis + motor (also optional but helped a lot with some z-banding errors in earlier printing)
• stronger bed leveling springs (optional. At least the earlier ender-3s all came with some weak springs that wouldn't hold level very long)

Material:
PLA+. Acts just like a soft plastic you can sand, file, or carve with your exacto knife.

Slicer:
Cura
Relevant Settings:

• Layer height: .08mm (.12 works ok as well if you want it a little faster)
• Wall line count: 3
• Alternate extra wall
• Print Thin Walls (very important - otherwise you lose fine details like bolt heads)
• Initial Layer Horizontal Expansion: -0.1 (-0.25 if your elephant foot issue is bad)
• Z-seam alignment: user specified
• Z-Seam X: -100mm (the biggest source of uncleanliness is the start point. this moves this so all start points are on one short side and all the window start points are inside the cabin. You can see them in preview mode as white vertical lines or spots)
• Top/Bottom Pattern: Concentric (this makes the outside pattern on the top straight lines. At this scale they look like wood-grains)
• Infill: 100%
• Infill Pattern: Concentric
• Print temperature: whatever works with your filament that creates the least stringing
• Flow: 105% (I was getting some serious underextrusion which led to brittleness/holes after changing to a .2mm nozzle. If you get the same try upping this by 2% a time)
• Print Speed: 40mm/s (slower leads to more stringing and cleanup, so it actually does need to move relatively fast)
• Travel speed: 130mm/s (same again)
• Retraction distance: 5mm
• Retraction speed: 50mm/s
• Combing Mode: All or Not In Skin
• (If using supports):
  
  • Support angle: 10
  • Support pattern: zig zag
  • Support density: 5%
  • support Z distance: .2 (this one especially makes it a bit easier to break off the model)

Everything else I believe is left at default. I'm not an expert on these and still have a little stringing from time to time so any suggestions are welcome to improve this setup.

Supports and build plate adhesion only as necessary for whatever model you're printing. Generally I have a brim on all of my parts to help protect against corner lifting/warping. Printing a brim also gives me warning about when I have to re-level the bed. If the lines have gaps it means it's time. To ensure full quality I'm currently releveling the bed every 6 prints. I'll be adding auto-bed leveling when I take the printer down for maintenance.

[sid]

very good .. i too love my printer and when set up right its great i love octo print setuo on a pi4 atatched to the printer. you can adjust temps ect as you go along in printing real time..
it makes printing easy an adjustable too, all from my computer and best part is i can turn off the computer and my prints still go on printing.

[Army-Gandydancer]

@Woodat, the more I look at the photos of your printed Overton cars while comparing them to the Athearn cars, I would say yours came out really well.

[Pencil]

Very nicely done - thank you for sharing!

For old-style trucks/bogies, Panamint on Shapeways has quite a few nice varieties: https://www.shapeways.com/shops/panamintmodels. A little more than 75c a piece, though (and I don't know about shipping to the UK...)!

Curtis

[ChicagoNW]

Thanks for the info on what and how you have explored on the printer.

As I model traction equipment, I am constantly kit-bashing and experimenting. The little Roundhouse Overtons are a favorite for building MOW cars.

The bodies are often combined with Bachmann Brill roof and ends to make Boxmotors. Freight versions of streetcars and interurbans.

The Kato Critter chassis are almost as important as the Bachmann Streetcar chassis. But the side frames are condensed versions of Japanese equipment. This often makes a nice model look bad. The fix has been a bit of a kludge.

Kato 8 wheel conversion(L) and Tomix(R) with Brill sideframes.
Cutting and sanding off as much of the sideframe yet leaving enough plastic to support the contact strips. Then glueing on replacements. A better solution would be to create a replacement truck with the correct side frame. Inserting the original metal contacts to make them functional. Tomix/TomyTec and BanDai just have the side frames as separate parts. Even a crude version of the Kato-Brill truck would look better.

Another liability of the Kato chassis is its lack of weight. In the 8 wheel conversion, I used a 1/16” brass plate with the end plates soldered on. In your situation you might try a variation of what the resincasters do. Use the printer to encase bits of brass and tungsten in the plastic. You might consider the deck, boiler and fuel box. Of course the better solution would be printer that uses metal instead of plastic. If not consider replacing much of the plastic with metal parts. Ever gram counts. So the use the plastic as a frame for metal bits. Using it for shapes that are harder to make in metal.

I asked about the interiors as they might be something you could sell. While the interiors, Brill and Shay conversion trucks might not make you a millionaire. They might pay for a few reels of plastic.

[Woodat]

Oh my goodness, I didn't even think of embedding metal as I print. That could work, just have it pause at various layers, drop in the weight, then continue the print.

I'll have to have a think on that. It'll be a while before I return to the climax but that would solve having to design it to be glued together. Thank you

[Woodat]

On a more rolling stock note, finished modeling up and printing the first iteration of the luggage/freight car. Without decals it'll be rather boring however. Will be a few days before I can slap some paint on it though. Will hopefully have the observation car modeled and printed also within the next day or two. If I get it done I'll paint them together.

Once these are done I'll be turning back to a few other pieces of rolling stock (simple early coal cars and logging/bolster wagons). I've also got a couple bachmann 2-6-2s now also and hoping to make a working loco between them. After that it's the layout. All in good time though

Anyway, a couple quick pics

[Woodat]

An evening of successes! Got one of my eBay bachmanns running and the cars pull! I had reservations given the cheap plastic wheels but away it went, even under low power.



I've also finished modeling up v1 of the observation car and its hot off the printer (along with two luggage/freight wagons). I'm out for a few days but once I get back I'll get them painted And finish off the thread. A few other wagon types will be next then it's on to building a layout. Then probably a return to these to fix some modeling errors and make another rake in a different colour scheme

[Woodat]

Luggage wagons and observation car are primed and ready for painting. Also included in the batch are the next items on the list: a few flat wagons and coal cars. The coal car itself is an homage to the 1870's coal car stamp (which itself was a hand-drawn homage to a coal car produced during that time-so there's no way any measurements are right). These tiny wagons will be weighted down with some washers embedded under the deck. Hoping to slap some paint on these tomorrow





Reference links to coal car:
https://www.si.edu/object/132c-coal-...m_1993.2070.83
https://www.midcontinent.org/rolling...d_1879_lrg.jpg

[Pencil]

Looking great! (Now that you have already completed your model) I do have drawings / measurements of several coal cars of that style ('coal jimmies'), if you are interested. For the luggage / freight car, I believe the prototype is in Nevada (http://www.nsrm-friends.org/nsrm34.html). I have drawings for that, as well (again, if you'd like). For my railroad, I'm torn between 'fixing' the Roundhouse / Athearn model and just printing out a new body....




Curtis

[Woodat]

I would love some drawings . While not zero, these models don't take a huge amount of time. And once I've done one it doesn't cost me any more effort (other than painting) to print ten as it did to print one. So I'm definitely happy to iterate on multiple designs.

I also want to go back and do a v2 of all of the overtons after I have a working layout. Currently all efforts are just to get things functional, so I'm not investing heavily In getting these first gens perfect. And with the lessons learnt from doing, There's more detail/design I now know I can do to them

[Woodat]

Took a brief break on the overtons to slap some paint on the coal wagon. I'm not bothering to clean it up much as there'll be some later iterations, but it definitely looks cute

(Standard reference peanut m&m included in the last shot for scale)







I'll also say my camera picks up the printer aberrations far more than my human eyes can. The layer lines are invisible unless you're 6 inches from it. They're even more invisible if I use solid coats instead of washes for painting

[spiralcity]

Took a brief break on the overtons to slap some paint on the coal wagon. I'm not bothering to clean it up much as there'll be some later iterations, but it definitely looks cute

(Standard reference peanut m&m included in the last shot for scale)

https://i.postimg.cc/HWvv0tLD/13-DDC...0-F0349498.jpg

https://i.postimg.cc/HnnZDrBh/4-F1-D...2-F86-E485.jpg

https://i.postimg.cc/c48hRyjw/0457-A...BD9-BB7-D6.jpg

I'll also say my camera picks up the printer aberrations far more than my human eyes can. The layer lines are invisible unless you're 6 inches from it. They're even more invisible if I use solid coats instead of washes for painting

Nice job on the wagons. I get a kick out the couplers combined being as long as the wagon.