The Irish Railways 3d printing thread

[AnUnknownConsciousness]

6 minutes ago, Colonel said:

I'm hugely impressed with the whole 3D printing thing, especially the visualisation of how to draw/design something that can be printed as a single unit. But (and I am very much typing in ignorance here), is there too much emphasis on having that single, one piece print?

 Seeing what the talented folk on this thread are doing is splendid, but the time scale is considerable. I appreciate that R&D is not quick, but would printing more parts separately (ie producing a kit), be easier/quicker? Am guessing that if it is, then there would already be 3D printed kits out there for us to play with, but I do wonder.

 After all, a 3D printed loco body still needs a chassis and the whole thing then needs painting. Not inconsiderable tasks the the space/time continuum, but (mostly) part of the fun of model making. With the ever growing dearth of parts for scratch building, is this gap something 3D printing might fill?

I've tended to make mine as single-piece bodies with add-on roofs, footboards, etc, to provide strength and stability. My experience has been that resin prints have a tendency to want to warp, and I've found having single piece body+chassis mitigates that, though I use separate pieces for detail parts where it may be more trouble than it's worth supporting them as part of the print, or parts where it's otherwise not practical to make them part of the print. These generally end up being roofs, buffers, and footboards.

Whilst assembly would provide the same stability, it relies on parts remaining straight for long enough to assemble them, which I've found to be a challenge. There are also cases where single-piece prints make supporting the print easier to reduce clean-up.

[Colonel]

Interesting, so many thanks for that insight. However, maybe begs the question of whether the printing materials used are not fully fit for purpose? I've seen that you can get fittings like domes and chimneys printed in metal. No idea how that works, but suspect cost (money and time) would be a factor here.

 Either way, these are pioneering times, so all power to all you creative folk out there!

[AnUnknownConsciousness]

4 hours ago, Colonel said:

Interesting, so many thanks for that insight. However, maybe begs the question of whether the printing materials used are not fully fit for purpose? I've seen that you can get fittings like domes and chimneys printed in metal. No idea how that works, but suspect cost (money and time) would be a factor here.

 Either way, these are pioneering times, so all power to all you creative folk out there!

It's certainly a bit of a compromise. As far as available hobbyist equipment goes for 3D printing, the options are filament or resin, unless you start looking at outsourcing printing which is where the money and time cost you mention starts to come into it. 

[Mayner]

I have trialled a number of different resins to overcome the problem with brittleness almost inherent in printing with "top down" home printers.

I successfully trialled Monocure 3D (Australia) 'Engineering Resins"  including Tensile resin with a Flex additive and recently Impact resin. https://monocure3d.com.au/collections/engineering-3d-printing-resins. 

I don't know if engineering resins with similar characteristics/properties are available in Ireland or the UK

I used Tensile resin with flex additive as an alternative to whitemetal to produce some of the detail parts for a 2024-5 batch of etched kits and to replace damaged/missing large scale parts including caboose smoke stacks & handbrake wheels.

The original injection molded smokestack Accucraft 1:20.5 scale caboose.

Replacement 3D printed stack (different caboose!)

The smokestacks are quite vunerable in garden railway use two broke off/lost in recent years. Fixing upgraded to a metal pin/stud into a hole bored in the roof and bedded in silicone to try and provide some resilience.

 

Window and doorset for a  4mm Victorian Terrace printed in "Impact Resin'

The base is sacrificial to assist printing per -anunknownconsciousness/ advice.

I am planning to print a wagon chassis in Tensile to see how it compares with commerically printed chassis.

 3D Modelling/Printing in metal?

Lost wax (invesment) brass castings prepared from 3D models.

The brass detail castings (buffers, sand/tool boxes & tank filler) for my GSWR 52 Class kit were prepared from 3D printed (Shapeways) masters (2019?) These days I would simply send the 3D Model (CAD) direct to the casters who would print the master in a 'burn away' resin rather than wax!

I have used Morris & Watson a locally based caster who supplies to the jewellery industry, and kit/model suppliers. https://morrisandwatson.com/

I would expect that similar casters exist in the UK.

3D printing in Aluminium. 

I use(d) Facfox https://facfox.com/# for the commercial printing of kits and rtr wagons with their SLA-abs-like resin. I found their prints quality and customer service to be to a consistent high standard and pricing (incl shipping) highly competitive compared to local and UK based suppliers.

NZR 9mm scale modellers (O gauge track-3'6" gauge) have have produced 3D printed aluminium drive components including , gears, flywheels, gearbox casings.

[skinner75]

Group of Irish drifting lads 3d printed the whole front end of a car build - can't find what resin they used though

https://www.youtube.com/watch?v=RM6ImzEZ3B8

[Broithe]

1 hour ago, skinner75 said:

Group of Irish drifting lads 3d printed the whole front end of a car build - can't find what resin they used though

https://www.youtube.com/watch?v=RM6ImzEZ3B8

Maybe they could print a tripod for the camera next?

[skinner75]

31 minutes ago, Broithe said:

Maybe they could print a tripod for the camera next?

Maybe they could

[Colonel]

Fascinating, but forgive my ignorance here - how does 3D printing with metal actually work?

[Mayner]

49 minutes ago, Colonel said:

Fascinating, but forgive my ignorance here - how does 3D printing with metal actually work?

Basically melting & fusing finely grained metal powder in an enclosed printer with a laser. Not exactly home/desktop equipment

https://www.ram3d.co.nz/metal-3d-printing/

https://www.renishaw.com/en/renam-500-metal-additive-manufacturing-3d-printing-systems--37011

Edited 23 hours ago by Mayner

[murrayec]

Here is a guy I follow, this is an old video of his first attempts in home metal 3D printing. It is rocket engine stuff, but I reckon there isn't many guys doing this for model train building! 

Eoin.

[Mol_PMB]

As with plastic/resin, there are several different 3D printing technologies for metal. they suit different sizes, materials etc. 

The metal equivalent of a filament printer is a bit like a MIG welder. 
It’s also possible to use chemical vapour deposition (as used for example to build up worn crankshafts) as a 3D printing technique. 
Then there’s the powder-based process which is basically laser sintering. 
For small and fine detail parts, investment casting using 3D printed wax masters is a half-way house. 
 

We have examples of most of these at the university I work at, but not in our department and I’ve never used them - but I’ve seen some of the results. 

[AnUnknownConsciousness]

Thought I should produce some actual models to add to my theoretical additions to the discussion, so here's my crack at an MGWR D175B 8-ton covered goods wagon, drawn up based on the HMRS drawing. This is the first print, and there are two accidental omissions if anyone spots them - one a detail part, and the other something rather important for getting an operational model - but I don't have any 28mm axles so I wouldn't be able to get it running anyway. I ordered a stack of 28mm axles from the S4 society a month or so ago, who are apparently out of stock and unsure when they'll get more, so unless anyone has suggestions for other sources it may be a while before I have a running model unfortunately.

The layout it's sitting on is my P4 model of Thurso in Scotland (very much WIP), and with the exception of the Heljan class 26 and two Hornby Generics in the far background, all the stock behind it is similarly printed to my designs. 

The model after post-curing. I remove supports from detail components (in this case the bracing between the W irons, brake rigging, and a couple of other spots) before post-curing, as it's easier to do it without damage while the resin is still pliable. The inside shot shows some extra lateral supports I've been using to reduce twisting, but I still ended up with a tiny bit through the body (due to the thin planks; 0.5mm thick, or a scale 1.5") so may add a couple of small removable lateral supports inside the body to mitigate this. Other vans I've done have been completely covered so I've had thicker walls, as it hasn't mattered, but here I want the detail visible.

 

 

And with the support strips removed, and buffers fitted at one end to see how it looks. You can see a bit of the twist through the body in the second shot. 

Once I can get my hands on some axles these will be going on 21mm gauge to P4 standards, to go with some early 5'3" Australian models I'm working on. I have the drawing for the matching 8t cattle wagon, the Ernie Shepherd 'Illustrated History' book on the way, and a copy of 'Locomotives of the Midland Great Western Railway' arrived earlier this week, so I have plenty of ideas forming about what to do next once I have this refined a bit more.

Sara

[Rob R]

Sara,

Excellent print.

Would it really matter if you increased the sides to 1mm thick? Printability would improve considerably.

Rob

 

[jhb171achill]

Wow!!! Looks amazing!! I’ll want a couple if they’re available eventually! 

[Mol_PMB]

There are quite a few good wagon drawings of this vintage in the IRRS archives. In some cases the basic construction and dimensions are similar, but with detail differences in vents, ribs etc. 

I also still have all my photos, measurements and diagrams of the 1900ish GSWR ‘big boy’ van that I need to draw up. That would male a good 3D print subject too. Hopefully I’ll get some time to catch up with life over Christmas. 

[AnUnknownConsciousness]

6 hours ago, Rob R said:

Sara,

Excellent print.

Would it really matter if you increased the sides to 1mm thick? Printability would improve considerably.

Rob

 

Thank you.

Realistically it wouldn't matter, I just like keeping things as close as reasonably possible to prototype dimensions where it's going to be visible. I do all my designs at 1:1 scale before adjusting for 1/76.2 which doesn't help, but makes it a lot easier to follow drawings - I used to do the design work at scale and I wouldn't like to calculate how much time I wasted converting dimensions! Some combination of additional supporting and slightly thickening the walls should do the trick. The bigger issue is the roof, I made the edges far too thin (nearly knife-edge) and the test-print was a failure, so it at the very least will need some thickening, but that's easy enough.

6 hours ago, jhb171achill said:

Wow!!! Looks amazing!! I’ll want a couple if they’re available eventually! 

Thank you. I'm slowly working with a friend who's a UK based modeller with the end-goal of getting some of my other designs (Highland Railway stock) available, so it's entirely possible. Given postage costs from Australia to Ireland and the UK I wouldn't fancy doing the distributing from here, knowing how prohibitively expensive that would make it.

Sara

[Colonel]

Amazing stuff. 're axles, I've long used 2mm brass wire for my 7mm scale, 3ft narrow gauge Irish models. Not too difficult to pin point the ends, while being non magnetic, you don't get problems with uncoupling magnets.