Wednesday, 9 January 2019


I'm usually quite circumspect and diplomatic on this blog.

I try not to go in for polemics or to stir up controversy for the sake of it, or just to get attention.

Every now and then, however, I feel that there is something which has to be said, and this is such an occasion.

The subject is 3D printing.

Or to be correct, 3D printing design and the degree of care and attention which does - and more frequently, doesn't - go into it.

This is not a rant against the technology.

We have a couple of 3D printed locomotive bodies ourselves which were designed by Robex who have created wonderfully detailed and fine models.

Here, for example, is a screenshot of one of their FR slate wagons.
There is always another end to every spectrum, sadly.

The other day, as I was googling around for pictures to research a model, I was led to a 'shop' on perhaps the most well-known 3D print site where I was appalled to come across a fleet of what were purported to be scale models of FR stock - some of it of very rare items of rolling stock of which I know of only a few previous models, all painstakingly scratch built.

(Many of which by me.)

In most cases what is presented are computer simulated images, not actual printed models, so it is impossible to judge them in reality, but what I can see on the screen makes it exceedingly hard for me to accept the stated claim that they are accurate scale models.

There are some dimensions which are just grotesque, and other parts which, frankly, might as well be built using Lego.

It seems to me that many of these designs are being 'knocked up' in almost indecent haste with seemingly not a care that parts of them bear no obvious resemblance to the real thing.

Some of the prices are, frankly, iniquitous, and I don't mind telling you that it makes me mad.

In my view it is even more important in this digital age to keep the words caveat emptor at the forefront of your mind.


  1. Very true. Anyone showing JUST 3D renders isn't describing their model accurately. Aside from the issue of proportion and detail, some things can be designed in CAD but don't work in real life when printed. You also have the issue of finish - the render looks lovely, the real thing? A lot less so, but they are selling on the basis of the render. And don't get me started on the "it can be sanded or just needs a thick coat of paint" arguments...

  2. I can't think who you're talking about Rob!! I took a punt on a couple of prints from this supplier, though thankfully not the carriages with their half timbered beading.

    The dimensions on the diesel body are strange and I wonder what drawings have been used. I don't know of anything being published. It's way too wide for an FR loco. The other looks OK but again it says it is designed for a specific mechanism which doesn't seem to have been anywhere the print or the CAD.

    Whilst it has allowed the modeller to produce their own possibly unique models, the trouble with 3D printing is that it allows the designer to think the drawing is the product rather than the print. Anything that says 'be the first to try this' - and there are still too many of them - suggests that even the designer hasn't bothered to get a test print done.

    Back in the day I've helped out manufacturers by building test shot after test shot to get the thing right before release. That doesn't seem to happen with the majority of the more prolific 3d designers.

    Caveat Emptor!

  3. I think a lot of 3D print designers are chasing the money. They think that getting a lot of designs out there will make their fortune. Also, it's a (potentially) profitable hobby for them as they don't have to provide any sort of sales backup. Test building kits costs time and money, but is essential if the model is to go together for the customer, but the 3D guys think that is beneath them...

  4. Unfortunately David, the second you update the file with even a minor change (one that won’t affect the end print ability), it automatically resets to first to try. And sadly, I do know some people can’t afford to test print every single minor change like myself. The bigger stuff? Yes that gets prototyped especially if it’s new but if it’s been printed before even in a past version of the design and I know it’s prints fine, I can’t afford to reprototype again. But that’s personal circumstance. Jon R, Bowaters Models.

  5. I want to make it clear that I have no connection with the person who you're talking about. I'm just another modeler who to be totally honest is getting sick of seeing posts like this.

    I agree that his models aren't accurate and would definitely benefit from further work and research. But are posts like this really helpful? Surely the older generation should be helping the younger generation perfect there skills.

    I've seen a lot of similar posts and comments in the past months all about the same shapeways user but no one ever seems to want to help him. After all everyone had to start somewhere and can you all honestly say your first modelling efforts were award winning? probably not. I know I can't.

    I personally feel that the development of 3D modelling is an extension of scratch building. Some people find working with sheets of plasti card or brass kits easy, others find using computer software just as easy. So we all have our preferred mediums. But again first efforts are rarely excellent models, it really does take time, effort and a lot of practice.

    So I propose instead of posts like this and the others I've seen online in the past months, why not offer to help the lad? offer him points and tips or even access to the same plans and drawing you have? instead of posts like this which will undoubtedly put him off modelling.

    Something for everyone to think about as I honestly feel like the 009 community is turning into quite a hostile place recently. It's certainly making me think twice about wanting to join in and share my own work.

  6. If it was just about modelling I'd agree with you, but the point is he (and others like him) are making these models available for sale with the intention of making money. Worse he's claiming they are accurate models of the prototypes when clearly they are not. To me that crosses too many lines, and I agree with the points Phil and David have made.

    In summary, if you are going to offer models for sale (be they 3D prints or kits in any other medium) you should be willing to put the time, effort, and money into checking that they work properly. No one should be selling models based purely from a render, and that's before we get anywhere near the issues of accuracy.

    I was a new 3D modeller once, and I put a lot of money into test prints before I made the models avalable on shapeways. I doubt I've ever broken even on the models I sell direct through shapeways because of that, and it drives me mad when I see people trying to make a quick buck in this way.

  7. (I should make clear that was in reply to the anonymous comment, not Rob's original blog post)

  8. Quite so. It is the misrepresentation which is maddening. There are laws against at this sort of thing. Just as you cannot sell ‘strawberry ice cream’ if it doesn’t contain a strawberry so neither can you sell - and this is the crux of it - sell - an accurate scale model which is demonstrably nothing of the sort.

  9. I have purchased some 3D prints from that popular site. I model in Nm - N gauge running on Z track amongst other scales and have built several RhB models which would probably never be mass-produced and have found the quality and fineness to be excellent. There are some very crude prints out there which do no justice to the hobby, but at the same time, there are some excellent prints which have had a lot of thought put in to the design out there also.

    1. Yes, I agree, there are some fantastic models available on Shapeways, unfortunately they tend to get lost in amongst the piles of absolute rubbish that people dump on there. Not only are the good models then hard to find, but the marketplace now has a deserved reputation for hosting models that are neither prototypical accurate or easy to clean and assemble.

      I think the main problem with a lot of these models is that people think they can knock out a 3D model on the computer and that will make something they can sell as a print. 3D printing is great... for some things, and for other's it's the worst possible option. Sheet metal, for instance, is never going to print well as you can never make it thin enough when viewed edge on, as it would be with a cab roof for example. By far the best option is to mix and match materials to get the best out of them all. That usually means kits featuring a mix of 3D printed and etched parts, along with wire and other detailing materials. The problem then is you need to invest money in assembling the kits for sale, and most of those dumping rubbish on Shapeways have no interest in spending money just making it.

  10. As someone who works in Additive Manufacturing I hear all the time that AM is a "wonder process". The simple fact of the matter is that it's not as simple as that. Some shapes are simply difficult to make using AM (straight lines, long thin pieces, cubes). Some models are just difficult to make using AM, that slate wagon actually looks pretty good considering the above.

  11. I agree that there are many good models on Shapeways, but to find these you have to sift through a lot of questionable stock.
    I recently decided (as a side project) to scratch build a few Ffestiniog 'Super Barns'. Partly as a bit of fun but also to gain skills (being only 16 years old). This was partly inspired by some of your excellent models.
    Now, I cant claim the two i have built so far to be truly accurate as I have made them from my own drawings based from photos and measurements but from what I have seen of similar models on Shapeways, mine give a much better representation of the prototypes. A will also say mine cost less than £60-70.

    I dont know how far i will go on this project as they are really too big for my layout but i am having great fun making them (more fun that spending £140 on 2 Shapeways models. For those interested i have finished a model of 119 and am now working on 125, with a plan to make a model of 150.