New to This Forum

[Marbelup]

Hello All

 

I have just joined the forum and I have been doing 3D modelling for about 2 months. I have been modelling the Western Australia Government Railways (WAGR) since 1980, in Sn3.5 scale (16.5 mm track = 1067 mm (3' 6") narrow gauge, 1/64 scale).

 

I have embarked on a fairly ambitious project to produce a model of a WAGR R class diesel locomotive - here is a prototype photo. The prototype was made in Australia by English Electric in the late 1960's.

 

So far, I have nearly completed the 3D model of the body, using Rhino 3D, and I have had some test prints done of the short hood only (about 10% of the loco body) by three of the 3D print bureaux in Europe, plus some contacts in Australia have kindly some test prints on their home-based desktop 3D printers.

 

The bogie sideframes, fuel tank and underframe are yet to be modelled. Fortunately, I have access to good prototype info including the manufacturer's general arrangement drawings, drawings published in an Australian magazine, and extensive photos of prototype locos, some of which are still operating.

 

I am using a custom-made drive bogie and matching dummy bogie from an Australian supplier. As of about 1 week ago, I have a running loco to use as a test bed, based on a footplate made from 3 mm clear polycarbonate, a styrene mock-up of the cab and long hood, and a 3D printed short hood.

 

I am leaning towards the Prime Grey material from i.Materialise although I am still on the lookout for a somewhat higher-res finish, particular as the loco has curved roof and ends which exacerbate the stepping from the 3D printing process. I have tried the Shapeways FUD material which was clearly the best in terms of fine detail and minimal stepping, but marred by unwanted ripple and texture effects, which seems to be common based on my limited exploration of this forum so far.

 

(I have attached a photo of the short hood in Prime Gray.)

 

My current strategy is to continue with the 3D design - I should be in a position to order a 1-piece body in a week or so - and put together a complete loco from Prime Grey material, and consider getting some parts redone if and when better quality materials become available at a reasonable price, as I am sure they will.

[Pugsley]

Looking good, other than the stepping. Have you considered using the Prime Grey for the body and etched parts for the details? That way you could smooth away the stepping with gentle sanding, and add the details afterwards.

[Marbelup]

Thanks Pugsley

 

No, I haven't considered that option, although I have done artwork for etched brass parts in the past.

 

To my mind, it sort of defeats the purpose if you have to add detail parts to the 3D print, apart from things like handrails which would obviously not be strong enough in plastic to withstand normal handling. Also, some parts of the loco have raised panels and recessed areas so it would be virtually impossible to sand the surface flat. There are a lot of small details that I can do easily with 3D printing which would be difficult or impossible to do any other way.

 

For now, I am content with a less than perfect surface finish, just to see what is currently possible with 3D printing. And, I can keep on eye on alternatives for higher quality 3D printing in the future.

 

On the layout, the overall finish appears better than in close-up photos. The worst stepping is on the curved roof, but even that is not too obvious as my layout is close to eye level.

 

I have attached a photo of the mock-up loco as it is currently.