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Australian V'locity DMU in N Scale - with 3d Printed mechanisms


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Hi all! 
 
I've just sent this off to Shapeways - but as they have quoted a month's turnaround on my order (printing in bronze, see) I thought I'd post some images of my model. It's an N Scale model of the V'locity DMUs in the Australian state of Victoria 
 
What took the longest time and most of the effort was working out a way of 3d printed everything or at least as close to it as I can so I won't have to buy a chassis which would then need to be modified to fit. So I've designed the bogies and the gearboxes to be 3D printed with the chassis as internal moving parts.
 
The green represents bronze electrical conductors, the yellow motory thing is a motor. 
 
For an added challenge I motorised both the bogies. This meant figuring out a way of getting electricity to the motor - preferably in the same carriage. While I can use the Kato metal wheels (which will used in the dummy cars) they don't have gears on them, so I'm printing out bronze wheels with bronze pick ups which are then connected to a a plastic gearbox and bogie.
 
Green for Bronze, yellow for moving parts.
 
 
Thanks all for viewing - I will update as soon as I receive my prints which may actually be a long way off...
 
Alan

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Hi Alan,

 

Very impressive work so far.  I have seen (and use myself) a fair amount of 3D printed stuff, but mostly for "cosmetic" components - I have not seen anyone really pushing the envelope with operating parts, so like others here I will be very interested to see how this goes.

 

Please keep us updated!

 

cheers

 

Ben A.

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  • 4 weeks later...

Thanks everyone, I will definitely keep you updated as the project evolves. At the moment it will be mid-june before I receive any prints at all so watch this space! 

 

Hi bluemattersoda,

 

Just checking if you have made any progress on your project? I model early 20th century USA traction in N scale and am very intrigued with the idea of building custom chassis to fit each model. All of my models are 3D printed but I have just been building the body shells and then matching them to Tomix/Kato/Bandai chassis. I like the Japanese chassis but sometimes they are hard to find and don't always match the wheelbase and size I'm looking for. It looks like you have put a lot of thought into your chassis design and I am very curious how it turns out.

 

By the way, nice job on the compound curves on the front of the DMU! By the screenshots it looks like you are using Rhino? I've been learning Rhino and am very happy with it but have found making compound curves always the hardest part of the model. I was pleasantly surprised to pull off a clerestory roof for an old wooden Sacramento Northern interurban though it took many hours and numerous do-overs.

 

 

Thanks, Darby

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This seems a logical extension of the art

 

Will shape ways be doing the metal printing? Is it laser fused deposition? Will be interested in the quality and what finishing will be required

 

Will you have stub axles with a printed plastic connector??

 

Nick R

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Hey there, 

finally received the prints! I've been mucking about with them to see if they all worked together or not, and as usual there are a few issues that one doesn't foresee on the computer screen. But first here are the prints! (I forgot to take a photo immediately out of the box - so everything is partially assembled)

 

I have to say I'm a little disappointed with the lack of detail on the bogies as it looks rubbish compared to the FUD body shells. I'm having another look into doing the bogies in FUD at the moment. 

 

Another disappointment is that the mechanics aren't working as well as I thought they would. Because Shapeways needs a clearance of 0.5mm between moving parts, this means the cogs tend to move about in their housings. I had accounted for this movement, though I did not foresee how rough the wheel rotations are because of this, nor how prone to jamming the cogs were. Again, I'm investigating FUD to give smaller tolerances to reduce the movement. I'm waiting for my n scale motor from North West Short Line before I can fully evaluate how successful my design is, but it's going to be three (three!) weeks for delivery.

 

 

 

EDIT: Sorry Nick, I meant that the metal parts are BRONZE, not brass!

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I read your thread yesterday and am very impressed with how far you have gone with 3D printing.

 

This is pioneering work using a technology that relatively speaking is still in it's infancy, so I guess it's not going to be a smooth path - but equally I'm sure others will find this project both inspiring and instructive.

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Hi bluemattersoda,

 

Just checking if you have made any progress on your project? I model early 20th century USA traction in N scale and am very intrigued with the idea of building custom chassis to fit each model. All of my models are 3D printed but I have just been building the body shells and then matching them to Tomix/Kato/Bandai chassis. I like the Japanese chassis but sometimes they are hard to find and don't always match the wheelbase and size I'm looking for. It looks like you have put a lot of thought into your chassis design and I am very curious how it turns out.

 

By the way, nice job on the compound curves on the front of the DMU! By the screenshots it looks like you are using Rhino? I've been learning Rhino and am very happy with it but have found making compound curves always the hardest part of the model. I was pleasantly surprised to pull off a clerestory roof for an old wooden Sacramento Northern interurban though it took many hours and numerous do-overs.

 

 

Thanks, Darby

 

Hi Darby, 

I don't know how I managed to miss your post in the first instance!

Yep, this is Rhino 4. I've been using it for the last 6 years for architecture school, and it truly is versatile. Keep at it - it does have a notoriously steep learning curve (many classmates have since given up on it!) but the rewards are great. 

 

I too am a fan of the Japanese chassis and having compared them to those from Britain (Dapol) they seem to be simpler yet just as effective. They're quite cheap in comparison too though the reason I have chosen the 'independent' path is because the supply of the tomix chassis is too uncertain - I believe the TM03s I've used on my Waratah (http://www.rmweb.co....e/#entry1042659) are no longer manufactured. 

 

Anyway, I am in the process of redesigning the motor chassis so stay tuned!

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I really like your work - very nice models.  I hate to be a naysayer but my instinct is that, even if you get the mechanism to work, it will wear out very quickly.  The SLA materials used for WSF and for FUD are both quite soft and high friction by the standards of what you would usually use for gears and bearings.  It's certainly what I've found on my prints, where I have been forced to include brass parts for anything moving.

Best of luck though, I really do hope that it does work!

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Hi Rabs, thanks for your reply. I have to agree with you on the plastic wearing out - the thought has been in the background as I design these! I guess the aim here is that once the geared bogie design is finalised it would work out to be quite affordable to replace the bogies when they do wear out. On the other hand, it would be interesting to print them out in metal in the future. Shapeways do print in steel after all...! If not there are places locally which can print in tougher plastics such as acetyl with (I'm guessing) similar tolerance to what Shapeways does in FUD or FD as the steel is quite low detailed. Anyway, I'll see how this all pans out!

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  • 3 weeks later...

HI all, 

Still in the middle of redesigning the new motor chassis, but here's a few photos of the paint job!

 

In Primer (Tamiya Fine):

 

Sprayed with Tamiya Spray Can Aluminium

 

And colours in Humbrol enamels. 

 

I have to say the enamels really ruin the appearance...it's much too thick and hides all the fine details; doesn't apply evenly and STILL hasn't dried after a week. Is this a problem with Humbrol only, or is there another way of doing colours that will keep the details? I've once masked and sprayed colours with great effect, but this is quite expensive for multiple colours (more spray cans) and means time consuming masking. Any ideas?

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I have heard several people complaining about humbrol enamels recently. I vaguely recall news about them being reformulated to meet new restrictions, particularly in regards to shipping. The symptoms all seem to match yours with the finish being too glossy and failing to dry properly.

 

Personally I switched to acryclics several years ago on the basis that they were easier to use and clean. There are several good ranges including Valejo, Citadel (Games Workshop) and Coat d'Arms. Finding an exact match for a particular prototype shade can be a bit time consuming but is worth the effort IMHO.

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Hello Alan,

 

Hard luck with the enamels. They will dry eventually in my experience but it could take weeks.

 

Having had a similar experience I now use halfords car aerosols for 3D printed models, and tbh I tend to stick to single colour items.

 

Cheers

 

Ben A.

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I tend to use the automotive spray packs for the primer and base colours (approximate colours are fine), then overpaint with the model enamels or acrylics with very thin coats - two or even three coats usually give sufficient depth without any brush strokes showing, Being thinned, the paint tends to dry more quickly too.

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For OO sized models I don't find the sprays too thick - I do a few thin sprays rather than one thick layer.

 

I can't say for sure it would work as well for N and smaller models but it would be worth experimenting with, perhaps, less critical models where it won't matter if things don't go quite the way you would like.

 

An advantage of such sprays is that the silvers and other metal finishes are a little more convincing than most of the available model paints.

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Hi Alan,

 

I think it's a balance - the car paints are probably a little too thick but the smoothness of the finish compensates for this IMO. They also give a good high gloss finish which is ideal for taking decals.

 

Cheers

 

Ben A.

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Thanks all for your responses! And Karhedron - great model! I can see how the car paints result in a smoother finish! 

 

I'm wondering if anyone has had any experience with decals as well. I've tried the inkjet home DIY variety and the colours aren't as solid as the ones you get in plastic kits so you get a sort of transparent print. Also, anyone know how to produce a decal for a rounded surface without having to trim it once on the model? there's a bit of a colour gradient happening on the front of the V'Locity, and i don't really want to invest in an airbrush to do that one small part!

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  • 1 month later...

So good and bad news...

The good news is that Shapeways has finally delivered my redesigned chassis! The bad news is that they forgot to send the wheel housing and substituted my bogies with two astronauts. The brass bogie pickup looks very good though, especially considering how small it is (bullet train for scale)

 

I did however manage to test the corkscrews with the motor. The parts needed some sanding and paring to reduce the friction, but then it works OK. It makes a helluva racket though. I will try to upload a video soon. 

 

In the meantime, I stripped the enamels and repainted the body shells with Mr Hobby acrylics. I have to say that the acrylics are far superior to the humbrol enamels I used previously. The acrylics apply smoothly and dries quickly. 

 

 

The V/Line logo is a decal:

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