3d printing for miniatures

3d printing – it’s the future, right? We’ll all be printing our miniatures at home in a year or so and GW will be out of business.

Well, let’s see…

I’ve been playing around with digital sculpting and 3d printing for over a year now, so I thought it would be useful to share some of my experiences. In this post I’ll focus on the various materials and printers I’ve tried. Be warned: this article will be text heavy and probably of limited interest to most miniature enthusiasts!

Shapeways frosted extreme detail

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FXD: difficult to see!

Frosted extreme detail (FXD) prints are created using a multijet modelling process. Basically the object is built up by depositing layers of molten plastic. Each layer hardens and is cured by UV light before the next layer is deposited. There is a wax support material that is removed at the end of the build process by melting it in an oven. Shapeways then clean the print before shipping it out.

 

Good points about FXD are that it is very precise – you can model a weapon with a properly sharp point or edge if you want to. And unlike other print technologies, there is no need for manual removal of support structures, so no risk of the part being damaged.

Each layer is only 16 microns in height (0.016 mm), so the stepping in the z-axis (vertical direction) is minimal. I don’t know what the resolution in the horizontal plane is, but it definitely doesn’t seem to be as good. This means that for a miniature you want it to be printed the right way up to get the best result.

Unfortunately Shapeways will orient the miniature as they wish in order to maximise the number of parts they can fit on the build tray. Combined with surface roughness that occurs where the support wax contacts the part, this leads to a lack of consistency. I have printed the same miniature twice and had markedly different results.

It is possible to clean up FXD prints to a standard that allows for high quality painting. I have had success with 400 grit sandpaper, but of course you do have to be very careful not to obliterate details. When cleaning the material the transparency of FXD is a pain, as it makes it very easy to miss rough areas and stepping lines that only become apparent when the painting has started.

Shapeways black high definition acrylate

dragon_maiden7Recently Shapeways have started offering the snappily titled black high definition acrylate (B-HDA). At the time of writing this is a maker only material, so it’s not possible for anyone other than the model owner to order a print.

B-HDA is a direct light projection (DLP) technology. The part is built one layer at a time by projecting cross sections of the design onto a bath of liquid resin, causing it to cure where the light hits it. This approach requires that support structures are created as the part is built to prevent it collapsing under it’s own weight.

Overall I have found this material to be a significant improvement over FXD for miniatures. The z axis resolution is given as 50 microns rather than 16, so I had expected to find a noticeable reduction in detail. In practice this doesn’t seem to be the case and even some very fine details I have included on my models have been reproduced. However, it is apparent that sharp edges are not quite as tight as FXD (though still very good).

The material is a bit softer and more flexible than FXD (which is somewhat brittle). I believe that this is how Shapeways are able to achieve a reduction in print artefacts despite the apparent lower resolution of the process. It seems that the material ‘relaxes’ a little as the piece is created, smoothing the surface. Because the material is also opaque, it’s significantly easier to clean up for painting. I generally use 800 grit. You probably could paint straight onto it, but I’m quite fastidious about surface prep!

Reproducibility seems to be better with this material, but at this point I don’t have enough B-HDA prints to say this with total confidence.

The major downside is those support structures. Shapeways are fairly good at working out where to place them but not perfect. For some models I’ve actually resorted to building my own support structures in to the .stl file when I found I was getting repeated failures in the same spot. Shapeways don’t offer the option to remove the supports yourself, so you just have to hope that whoever does it doesn’t mangle the miniature too badly! (To be fair, they have been pretty good with this in my experience but I’d still like to do it myself – presumably this could reduce the cost of production too.)

Formlabs Form 1+ and Form 2

I have also explored the possibility of buying my own printer. This would greatly speed up the design process, since I could test a design in a matter of hours rather than weeks – it’s so frustrating to receive a new print and immediately realise that something needs to be fixed!

There are plenty of desktop printers available for a few hundred quid, but they generally seem to be of the fused deposition modelling (FDM) type. From the research I’ve done, these printers are nowhere near good enough for producing miniatures.

Currently there are a few DLP printers available to the home user, but the cost is an order of magnitude higher. The Form 2 printer seems to be the best on the market in this group, but it will set you back three grand. And the resin is more than a hundred quid a bottle. And the build platform needs to be replaced every two bottles…

I have procured test prints of my miniatures on the Form 1+and Form 2 printers from a couple of UK based companies using 3d hubs. The minimum step height of these printers is 25 micron but I would say that the results are not quite as good as B-HDA from Shapeways (but still very good). I suspect that the difference lies in the resin. I have tried the black and the grey resin – they’re both more brittle than B-HDA (particularly the grey) and it seems to result in more visible stepping.

I have played with the free to download PreForm software that prepares a .stl file for printing on a Form printer. It’s very easy to use and gives full control over the placement of support structures. Unfortunately the setting that automatically generates supports places a lot of them (even on the lowest density setting) and they tend to be quite thick. This results in a lot of wasted expensive resin and makes it more difficult to clean up the print.

If I had my own printer I reckon I could get away with fewer, thinner supports for my miniatures but it’s not something you can really experiment with when someone else is doing the printing – understandably they’re worried about the print failing and prefer to stick to what the software says is needed.

Overall I think the Form printers have potential for miniatures, but I’m not prepared to gamble so much of my own money to find out!

Envisiontec perfactory

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Envisiontec print on the left, B-HDA on the right

Envisiontec perfactory printers seem to be the best that is currently available for high detail. Through various nefarious means I have been able to obtain samples of a few of my 15 mm miniatures printed on one of these machines and they are indeed a wondrous sight to behold. In fact the prints are so good that they evoke feelings of inadequacy in this neophyte sculptor: you dare to print your nonsense on this tool of the Gods? Foolish mortal!

As far as I know these machines are also of the DLP type, but the witchcraft that Envisiontec possess makes them clearly superior to any of the other printers I have encountered. In fairness there are still some very slight print artefacts, and there are still supports that have to be removed but otherwise the print will be an almost perfect rendition of the digital file.

As I understand it, if the RCP30 resin is used the prints can be placed directly into black rubber moulds for metal casting, but this is not something that I have explored further.

It’s difficult to find out exactly what one of these machines costs without contacting Envisiontec’s sales department, but I’m fairly confident you’re looking at 5 figures.

If you’re interested in obtaining your own Envisiontec prints I recommend Timo Laumann in Germany or RN Estudio in Spain. I also got some quotes for prints from some UK companies. Let’s just say they were uncompetitive…

Cost of prints

It’s probably worth giving some idea of the cost per print on the various options I’ve discussed above. Obviously there are several variables – the size of the miniature and the exchange rate being the obvious ones.

Currently a print of my dragon maiden would cost me £14.22 in FXD. Shapeways also offer a slightly less detailed frosted ultra detail option in the same material. That would be £10.20, but it’s not worth bothering with in my opinion.

B-HDA is £9.39 for this miniature. But it should be noted that part of this cost is the flat rate of $5 per part, so even a tiny 15 mm miniature would end up being £6+. You can reduce the impact of this by making several miniatures into a single part using sprues, but this has to be done in the right way or the model will be rejected under Shapeways ‘no sprues’ rule!

The other notable expense when using Shapeways is the cost of shipping. The cheapest option is UPS at about £8 a time (Netherlands to UK), even for a tiny lightweight package.

Quotes for prints on a Formlabs printer vary a bit, but are generally a bit cheaper than using Shapeways (plus much cheaper shipping). I’ve calculated that if I had my own printer each miniature would cost around £1 in consumables but the upfront cost is obviously steep.

There’s a wider range in the Envisiontec quotes I had, but you’re probably going to be looking at somewhere in the region of £100 for a single 30mm miniature. Only to be contemplated if you’re serious about going down the casting route!

Conclusion

I hope this rather gargantuan post will be useful to somebody – I certainly struggled to find out a lot of this information since the pool of people out there trying to print miniatures seems to be quite small. And I’d rather not think about how much I’ve spent in total on my various experiments!

The technology is moving quite quickly, so this information may soon be out of date. But unless there is a big new development in 3d printing technology I don’t see the picture changing massively in the short to medium term. I think GW and the rest of the industry are safe enough with their current business model for the time being!

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4 thoughts on “3d printing for miniatures

  1. Glad to here they are coming along. I tried their cheapest level fro my TMNT and it’s very grainy, but i wanted to see what the baseline was for 3d printing these days. It’s getting there 🙂 It makes for fun quick minis at and affordable price. No better or worse than bones i would say if you want quick test minis 🙂

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    1. I did get some prototypes for a ring printed in the strong & flexible plastic at Shapeways and it was fine for checking sizing but I wouldn’t use it for anything where the details were important. The design rules aren’t really suitable for 15 mm miniatures either, so I can’t really use it to check proportions unfortunately.

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  2. Clean your FUD or FXD parts in Bestine. A good long soak is fine. When dry, they will be an opaque off-white. Much nicer to see the detail.

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