1/15 scale Big Boy anyone?

DGE-Railroad

DGE-Railroad

The Orchard Line
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I'm not sure how I haven't managed to stumble across this before but I noticed the Makerbot-commissioned Big Boy design on Thingiverse yesterday. Has anyone else seen this?

Big Boy on Thingiverse

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It's an impressive piece of design The entire thing is downloadable for printing although you'd be pretty insane to attempt it at full scale :p

It piqued my interest though, as a kit bashed Big Boy is on my bucket list and I am hoping that some parts such as the boiler, front, cab and tender may be worth printing out for it. It'd certainly be easier and more accurate than if I tried to scratchbuild those parts. Scaling the relevant parts down by 75%, should bring it down to 1:20.3 I think.

I've tried one of the cab pieces with some rivet detail and it's come out pretty nicely.

The tender is available as a seperate Thingiverse thing
Big Boy tender
 
Greg Elmassian said:
if you scaled it down to 1:20.3 I believe the gauge would be wrong, i.e. NOT 45mm
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Doh!
Yes. It probably would.

I'm less worried about the wheel gauge, as I'd only be printing out the bodywork rather than the mechanics, but it'd still need to be proportional. It'd need to go down to something like 1:29?
 
Exact scale for 45mm in standard gauge would be 1:32

You could probably scale it to 1:29 and the drivers would be a little narrower than they should be, but you don't hear from people how awful 1:29 scale with 1:32 driver width looks. Plus if you are bashing, getting a couple of Aristo Mikados would make sense.

Greg
 
Paul M said:
Out of interest, how long would it take to print such a beast, any ideas?
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From what I've read, someone has printed it out at 1:33 and it took 3 months.

That's the entire loco though (without tender) and they didn't state whether that was a single printer (probably safe to assume it was) and whether that's 24x7 printing, any reprints or whatever
 
DGE-Railroad said:
From what I've read, someone has printed it out at 1:33 and it took 3 months.

That's the entire loco though (without tender) and they didn't state whether that was a single printer (probably safe to assume it was) and whether that's 24x7 printing, any reprints or whatever
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That is 3.5 years in doggy time.
 
DGE-Railroad said:
From what I've read, someone has printed it out at 1:33 and it took 3 months.

That's the entire loco though (without tender) and they didn't state whether that was a single printer (probably safe to assume it was) and whether that's 24x7 printing, any reprints or whatever
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Not a 10 minute job then
 
Paul M said:
Not a 10 minute job then
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It *could* be....but you'd probably need an awful lot of printers :D

I'm printing out the cab pieces at 1:29 now, and have the boiler/smokebox and tender rescaled and waiting. These are all quite large pieces so it shouldn't take too long to get a sense of what it should look like, without printing out the tens of other parts which wouldn't be needed for a kitbash anyway.

I'll post back when I've printed out enough parts to put something together. Its vying for printer time thanks to requests from my daughter at the moment :)
 
Bet it won't do R1.... :D
 
Cab, domes, funnel and smokebox door are printed I'm now ploughing through the rescaled boiler and smokebox sections.

Next up is going to be assembling the jigsaw to start getting an idea of how it could look. Thankfully there's a .easm file which can be used to see where everything goes!

It's pretty cool in fact. You can spin and zoom the model in either assembled or 'exploded' form, and hover over a piece to identify it
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EDRAWINGS2.png
 
A quick shot of the completed cab. The boiler and pipework are printing

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I'm feeling my way a bit with the construction. I've opted for uhu to glue the parts as I felt it gave me the best combination of adhesion, positioning, drying time and gap-filling.

It will all need filling, primering and painting eventually.
 
The body of the Big Boy is done and now it's a case of working out the jigsaw puzzle to assemble it, while the printer works its way through the tender parts (fnarr fnarr)

Once ive worked out where everything goes and if any need a reprint, it's onto the steam pipework. Gulp.

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Out of curiosity I looked at what getting a driver printed in metal would cost. As expected, it's quite prohibitive given the quantity needed for something like this even in a cheaper medium such as steel.

Interestingly though, that led me to find the technique of lost-PLA casting; it's possible to use the PLA to form a mould in water soluble plaster: The PLA is melted out and the mould can then be used to cast in aluminium and then rinsed away. I'm probably late to the party with this but I found it fascinating. It's an interesting blend of old and new technologies.

So if you have access to the forging equipment (and I appreciate that could be quite an 'if' :D ) it should be possible to transfer any parts you 3D print, to metal if you need to. Pretty cool.
 
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