The awkward bit at the top
This article has been published for the benefit of all model horse collectors. It is offered for free as my own investment into our wonderful hobby. I am always happy to discuss these subjects via email but this does take valuable time which, as a working Mum is a rare commodity these days! Previously I have developed a number of in-person workshops that were wonderfully fun and were welcomed by hobbyists looking to develop their skills. I pride myself on offering accurate information and quality illustrations. Sadly these in-person workshops have been postponed since Covid reared its ugly head, but I truly love teaching and do miss it terribly. Writing articles and creating informative content that educates and elightens is a passion I wish I could expand on, I would love to produce more articles covering all aspects of the subjects I can offer from my experiences.
If you have enjoyed this article and found is of value to you, and of course ONLY if you are in a comfortable position to do so, a small contribution would help me expand upon it. I don't drink coffee, so if you want to buy me a drink then the cost of a cup of tea would go a long way.
It is completely optional and you are most welcome to skip by this section, read on and enjoy this page and what it offers!
With your support I can enhance the page with illustrations and examples and make it even more useful to both new and seasoned collectors alike. If this goes well I will also be able to offer more articles that you may find useful during your involvement in our hobby.
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If you have enjoyed this article and found is of value to you, and of course ONLY if you are in a comfortable position to do so, a small contribution would help me expand upon it. I don't drink coffee, so if you want to buy me a drink then the cost of a cup of tea would go a long way.
It is completely optional and you are most welcome to skip by this section, read on and enjoy this page and what it offers!
With your support I can enhance the page with illustrations and examples and make it even more useful to both new and seasoned collectors alike. If this goes well I will also be able to offer more articles that you may find useful during your involvement in our hobby.
.
If you see anything on this page that is incorrect, or you would like to contribute, please use the form at the bottom of the page to let me know!
Latest update: 15th September 2021
Latest update: 15th September 2021
Why is 3D printing Even a thing?
3D printing, also known as additive manufacturing; a method of building physical models using a layered printing technology. It has been around for a surprisingly long time with the first 3D printers appearing way back in the 1980s! 3D printing has been used within our industry ever since the birth of the "minified" model in the mid 2000s where it was used to create the original mini models which were then refined by hand and cast in resin, but has only recently got to the point where the quality of the printed models is good enough for it to be used as a way to produce actual production models.
Resin model horses have been the go-to for artists for many years now, there isn't much you can't recreate using a rubber mould and resin (aka "liquid plastic"), but there are some limitations. 3D printing can offer a way to produce some features that casting can't, such as the chains on my Thistledew model below.
Resin model horses have been the go-to for artists for many years now, there isn't much you can't recreate using a rubber mould and resin (aka "liquid plastic"), but there are some limitations. 3D printing can offer a way to produce some features that casting can't, such as the chains on my Thistledew model below.
So what actually IS 3D Printing?
You've heard the term banded about for a while now, you know it's different to resin casting or plastic injection moulding, but what does 3D printing actually mean? 3D printing is simply the action of creating a three dimensional item using an additive process. There are lots of types of 3D printers which I've detailed further below, but here is the general process used to make the 3D printed models you've seen appearing in the model horse hobby recently:
3D printers build up a model by laying down very thin layers of resin on top of each other, building them up to make a fully 3D printed item. But before they do this an artist must create the model in digital form - you cannot 3D print from a photo. This 3D modelling is usually done in a computer program such as ZBrush, Blender or Nomad (there are LOTS of programs that can be used, I wouldn't say any are better than others, this part is all down to the skills and preference of the sculptor) and starts either with a scanned digital version of a real (clay) model, or a virtual ball of clay which is sculpted in the same time consuming way as clay, just inside a piece of software on a computer.
Then, once this digital model is perfected, the person printing the model (who may not be the same person who sculpted it) sets it up to print, which involves rotating the model to the perfect orientation for good printing and adding a support structure; vertical pillars that print along with the horse to hold in in place and make sure that any overhanging parts print successfully. Printing artists (as I've now decided to call them) are the equivalent to casting artists, so for example, if I set up and print a model I am effectively now the Mountain View Studios of it, just using a printer and resin rather than a mould and resin to produce my copies.
Using more software (specific to the printer being used, so these vary), the model is then "sliced" by the software into layers to translate the 3D model into 2D data that the printer can understand. Each slice is effectively a black and white silhouette of the layer it represents. In theory you could create a 3D print from a regular ink printer, getting it to print out each slice on a piece of paper, you'd then have to cut them out and glue them together, but you'd end up with a 3D model created in a very similar way to the ones you see sold at the moment, albeit yours would be made of paper and glue, not resin.
Before slicing there are some important settings that control the quality of the final print. Just as with a regular printer, you have "Best" and "Draft" quality settings depending on whether you want quality or speed, the same goes with 3D printers. The main setting adjusts the thickness of each layer, so for a faster print you opt for thicker layers as there would be fewer, so it would print faster, but those layers will be quite visible, may obscure details and could be problematic for prepping, so generally a thinner layer is used to get a smoother finish. Be aware though - bizarrely, just cranking the printer up to maximum DOES NOT guarantee a perfect print! This is where an experienced and knowledgeable person needs to use their skills to get the settings just-so, for the best results.
After slicing, the print file (effectively a large number of black and white silhouette images) is sent to the printer which has been set up with a resin mixture specific to the requirements of that model, and off it goes. Generally a micro mini scale model can take anywhere between one hour and one day, depending on the printer and the number of models being printed at once.
After printing there are a few processes the model goes through, first it has to be washed, to remove all the uncured resin and give a nice crisp finish. Not done properly you will get shiny spots, sticky spots or even blurred areas where the details haven't been cleaned properly and liquid resin has filled in the details and later cured. Some printers then require a post-cure to strengthen the finished model, which just means the model is heated and exposed to strong UV light for a short amount of time. After that the printing process is complete and the model can be carefully removed from the supports that held it to the printer build plate, if not done carefully the supports can tear away, leaving little divots in the model which need to be filled (these are as annoying to prep as bubbles are in cast resins!). Once trimmed the model is "cleaned", this means sanded and filed to remove the little bumps left by the supports and sometimes a light sand is done in areas where print lines are visible.
Finished models can look a bit dusty from the final cleaning process mainly as they aren't usually white (which hides the dust and sanding marks on the white resin casts we are used to seeing), so the sanded areas show more, which is fine but they should not have any deep scratch marks showing from heavy-handed or rushed cleaning, and should not have visible support bumps. If they did this would class them as "raw" or "trimmed only" as they have had the supports trimmed away but have not been fully cleaned. Just as with cast resins, even well cleaned models may need a final once over after priming to remove all traces of their production.
3D printers build up a model by laying down very thin layers of resin on top of each other, building them up to make a fully 3D printed item. But before they do this an artist must create the model in digital form - you cannot 3D print from a photo. This 3D modelling is usually done in a computer program such as ZBrush, Blender or Nomad (there are LOTS of programs that can be used, I wouldn't say any are better than others, this part is all down to the skills and preference of the sculptor) and starts either with a scanned digital version of a real (clay) model, or a virtual ball of clay which is sculpted in the same time consuming way as clay, just inside a piece of software on a computer.
Then, once this digital model is perfected, the person printing the model (who may not be the same person who sculpted it) sets it up to print, which involves rotating the model to the perfect orientation for good printing and adding a support structure; vertical pillars that print along with the horse to hold in in place and make sure that any overhanging parts print successfully. Printing artists (as I've now decided to call them) are the equivalent to casting artists, so for example, if I set up and print a model I am effectively now the Mountain View Studios of it, just using a printer and resin rather than a mould and resin to produce my copies.
Using more software (specific to the printer being used, so these vary), the model is then "sliced" by the software into layers to translate the 3D model into 2D data that the printer can understand. Each slice is effectively a black and white silhouette of the layer it represents. In theory you could create a 3D print from a regular ink printer, getting it to print out each slice on a piece of paper, you'd then have to cut them out and glue them together, but you'd end up with a 3D model created in a very similar way to the ones you see sold at the moment, albeit yours would be made of paper and glue, not resin.
Before slicing there are some important settings that control the quality of the final print. Just as with a regular printer, you have "Best" and "Draft" quality settings depending on whether you want quality or speed, the same goes with 3D printers. The main setting adjusts the thickness of each layer, so for a faster print you opt for thicker layers as there would be fewer, so it would print faster, but those layers will be quite visible, may obscure details and could be problematic for prepping, so generally a thinner layer is used to get a smoother finish. Be aware though - bizarrely, just cranking the printer up to maximum DOES NOT guarantee a perfect print! This is where an experienced and knowledgeable person needs to use their skills to get the settings just-so, for the best results.
After slicing, the print file (effectively a large number of black and white silhouette images) is sent to the printer which has been set up with a resin mixture specific to the requirements of that model, and off it goes. Generally a micro mini scale model can take anywhere between one hour and one day, depending on the printer and the number of models being printed at once.
After printing there are a few processes the model goes through, first it has to be washed, to remove all the uncured resin and give a nice crisp finish. Not done properly you will get shiny spots, sticky spots or even blurred areas where the details haven't been cleaned properly and liquid resin has filled in the details and later cured. Some printers then require a post-cure to strengthen the finished model, which just means the model is heated and exposed to strong UV light for a short amount of time. After that the printing process is complete and the model can be carefully removed from the supports that held it to the printer build plate, if not done carefully the supports can tear away, leaving little divots in the model which need to be filled (these are as annoying to prep as bubbles are in cast resins!). Once trimmed the model is "cleaned", this means sanded and filed to remove the little bumps left by the supports and sometimes a light sand is done in areas where print lines are visible.
Finished models can look a bit dusty from the final cleaning process mainly as they aren't usually white (which hides the dust and sanding marks on the white resin casts we are used to seeing), so the sanded areas show more, which is fine but they should not have any deep scratch marks showing from heavy-handed or rushed cleaning, and should not have visible support bumps. If they did this would class them as "raw" or "trimmed only" as they have had the supports trimmed away but have not been fully cleaned. Just as with cast resins, even well cleaned models may need a final once over after priming to remove all traces of their production.
How many kinds of 3D printing are there?
3D printing is a generic term used to describe the creation of a three dimensional object by a machine. There are quite a range of different ways to 3D print, from melting layers of metal to printing concrete houses and even drawing into a vat of gel! To keep things simple, and relevant to this page, here's a very quick low-down on the main ones:
FDM - Fused Deposit Modelling
This method uses reels of plastic thread, or "filament" (usually PLA or ABS) which is drawn through a hot nozzle that melts the plastic and uses the liquified plastic as though it is ink to draw out the layer onto a print bed, adding layer upon layer to create a 3D item. You can often tell when a model is FDM printed as they often have visible layer lines but also a lovely iridescent sheen to them. FDM printers are usually limited to just one material at a time, but sometimes have multiple nozzles to allow for parts with a variety of materials in one piece. Occasionally dual nozzles are used with one printing with the build material and one printing with a support material which may be designed to break away after printing, or to be soluble to allow it to be removed without leaving any visible traces on the model. As far as I'm aware FDM printing for production is currently only used by Hartland within the model horse hobby. Here is a good illustration of FDM printing in action. As FDM printing uses plastic type materials (PLA, ABS, Nylon, Polycarbonate etc) the printed items can be used in a much wider variety of applications as they are strong, flexible and are not prone to developing brittleness like those made with other (resin type) printing methods. Sadly the surface finish is much less smooth than models from other methods so not as well suited to model horse type applications. One great benefit of FDM printing is the size of the models that can be built, as these machines often have generously sized build volumes.
"DLP" [blanket term]
LCD - Liquid Crystal Display / DLP - Digital Light Processing*
This entry-level type of 3D printing for model production is very common in the model horse hobby. I'm using DLP as a blanket term for LCD and DLP style printers as the way they work is very similar. DLP printing uses a vat of liquid resin with a see-through, flexible film bottom. With LCD printers this sits directly on top of an LCD screen, with DLP printers the vat sits on top of a piece of glass with a mirror below at 45 degrees with a projector unit which projects the image onto the mirror which transfers through the glass to the bottom of the vat . A build platform is lowered down into the vat of resin (these models print from the top-down), very close to, but not touching the film at the bottom of the tank. The screen/projector lights up a silhouette image of the layer needed and the UV light from the image cures the resin above the illuminated pixels. The cured resin adheres to both the build platform and the film. Once the layer is cured (between 1 and 30 seconds depending on machine and resin used), the build platform slowly lifts straight up, peeling the cured resin away from the film, then is gently lowered back down again, stopping a fraction of a MM higher than the last time, and a new layer is formed. Each layer adheres to both the previous layer and the film and when the build platform lifts it is peeled off the film. The forces involved with pulling each layer from the film can be high so setting the print up correctly is imperative to avoid visible layers or delaminated layers. Sometimes, on peeling, the model is so firmly stuck to the film that it breaks away from the build platform and sticks instead to the film resulting in a print failure, so sometimes DLP printing can be quite frustrating for the user and the results can be sub-standard, however, once the settings and set up have been "dialled in", these failures can be avoided and the surface finish can be excellent.
*Sometimes also referred to as Digital Light Synthesis or DLS
SLA - Stereolithography
This type of 3D printing is widely considered to provide the most fine details and best surface finish of any 3D printing method. SLA printing uses a similar method to DLP but instead of a screen below the resin tank is has a laser which draws out each layer. This makes it a slower process (usually) than DLP printing but as there are no pixels involved, smoother curves can be achieved. The latest SLA printers have been designed with a "low force peel" system where the film at the bottom of the resin tank is gently peeled away from each layer rather than pulled away in one go, this gently peel removes much of the force from each layer, resulting in even fewer visible layer lines on the resulting print.
With both DLP and SLA printing, the size of the models that can be produces is limited to a relatively small build volume. Recently much larger DLP and SLA printers have been released but have yet to make their way into the model horse hobby. It is unlikely that larger scaled models will be printed for production for the foreseeable due to the longevity issues around larger, hollow models using these materials and also the clean-up time, which is currently much longer than with cast resins due to the sheer number of supports that would be needed on a bigger print.
SLS - Selective Laser Sintering
This is a very different method to those above. Instead of using a vat of resin, a vat with a build platform sits below a laser and a fine layer of plastic or metal dust is deposited onto the platform and then the laser draws out the first layer silhouette. The laser fuses (melts) the dust particles together to make a solid layer. The platform lowers a fraction of a MM and then a new layer of dust is deposited. Gradually the platform lowers into the tank and the tank fills with the powder. As the unused powder remains in the tank along with the 3D printed part, the part effectively floats in the unused powder and therefore no extra supports are required to hold it up, so SLS printed items are ready to go as soon as the unused dust has been blown/washed away. SLS printing uses very fine plastic or metal dust, so is largely an industrial application, far too messy and risky for home-use, however smaller SLS printers are coming into the market now although even they would need very careful handling to be used safely. Models produced via SLS printing have an almost velvety finish to them, dictated by the size of the particles in the powder used. They are often used in parts manufacture for cars and appliances as they can produce large, strong, (even metal!) usable finished parts but due to the grainy finish they aren't yet suited to the requirements of the model horse hobby. SLS printed models are used within the jewellery industry but these pieces are often heavily polished, so the grainy surface finish on raw prints is not an issue.
Polyjet
Another multi-material industrial manufacturing method, Polyjet printing can produce multi-material multi-colour models. Similar to an InkJet printer it sprays fine droplets of material onto a build plate and then exposes them to UV light to cure. Building bottom-up it sprays each layer directly onto the one below, then cures it and repeats to build up a model. Using multiple nozzles to jet the liquid material allows these printers to produce models with a range of materials in one piece (ie a plastic handle with a rubber grip), in a range of colours. The colours possible are in the millions, however they are limited to the nozzles used so photographic blending of colours is not currently mainstream in these types of printers/ Due to the price of these printers they are mostly limited to larger industrial applications, however with the speed at which 3D printing in all areas is moving, we can expect this technology to become more accessible in the near future. The finish on polyjet models is generally better than that of MJF type printers, however still not quite up there with the SLA type printers.
There are many different 3D printing technologies with more coming along all the time. One interesting one (though perhaps not quite for model horses yet) is Rapid Liquid Printing which injects print material into a gel, the gel suspends the material so gravity is not an issue and the results are very cool! Used in mostly furniture and lighting design, this technology has now found its way into the automotive industry with a lot of promise for pneumatic applications. Yet another method uses projected light to selectively cure gel using photons! I am particularly interested in this one as you can build around other objects - in this movie you can see they build a handle around a metal screwdriver, does this mean we could potentially use wire reinforcements in future model horse creation?
3D printing is not limited to miniature models, as it is the term used for any manufacture method using an automated additive process, it is also used in much larger applications such as boat-building and even construction! 3D printing has even made its way into the gourmet dining industry with chocolate, vitamins and even pancakes being produced this way!
MJF - Multi-Jet-Fusion
I love this type of 3D printing and feel we will be seeing far more of it in the model horse hobby very soon! Basically similar to SLS printing in that is uses powder rather than liquid resin or melted plastic, but with MJF printing, instead of a laser that melts the powder, a bonding agent (glue) is printed onto the powder to make the layers. Not only does this give a finished model with no supports to clean (yey!), the bonding agent can be coloured just like ink, making it possible to print a coloured model using the full spectrum on one model! You sometimes see "minime" scanned people printed this way, where the skin tone and clothes colours are printed direct with the model for a fully coloured print straight from the 3D printer. MJF prints have more visible print artifacts (ie layer/voxel lines) than SLA and some DLP prints, however if you click the images below you can see that even these stablemate scale models are easily good enough to pit against other OF or commercial models.
MJF is another fast-moving technology designed for miniature models, so they are improving the finish quality and recently announced the ability to produce full colour miniatures for war-gaming type collectors. This is a real game changer for the miniatures industry as a whole and I'm very excited to see more colourful models coming into our hobby. It's going to be a real headache for show-holders working out which division to put these unique, custom yet machine-created models in!
The models below were 3D printed using a Multi-Jet-Fusion 3D printer. They are not painted - the colours you see were a part of the 3D printing process itself, so, whilst the digital sculpture and the colour design were created by an artist (me!), the 3D printer brought them into the final physical form. I believe these are classed as OF models, though they could also be considered OF Resin, Commercial Resin or even Artist Resin by some - the decision on which division they should show in lies with the Show Hosts and ultimately (in the US) with NAMHSA.
FDM - Fused Deposit Modelling
This method uses reels of plastic thread, or "filament" (usually PLA or ABS) which is drawn through a hot nozzle that melts the plastic and uses the liquified plastic as though it is ink to draw out the layer onto a print bed, adding layer upon layer to create a 3D item. You can often tell when a model is FDM printed as they often have visible layer lines but also a lovely iridescent sheen to them. FDM printers are usually limited to just one material at a time, but sometimes have multiple nozzles to allow for parts with a variety of materials in one piece. Occasionally dual nozzles are used with one printing with the build material and one printing with a support material which may be designed to break away after printing, or to be soluble to allow it to be removed without leaving any visible traces on the model. As far as I'm aware FDM printing for production is currently only used by Hartland within the model horse hobby. Here is a good illustration of FDM printing in action. As FDM printing uses plastic type materials (PLA, ABS, Nylon, Polycarbonate etc) the printed items can be used in a much wider variety of applications as they are strong, flexible and are not prone to developing brittleness like those made with other (resin type) printing methods. Sadly the surface finish is much less smooth than models from other methods so not as well suited to model horse type applications. One great benefit of FDM printing is the size of the models that can be built, as these machines often have generously sized build volumes.
"DLP" [blanket term]
LCD - Liquid Crystal Display / DLP - Digital Light Processing*
This entry-level type of 3D printing for model production is very common in the model horse hobby. I'm using DLP as a blanket term for LCD and DLP style printers as the way they work is very similar. DLP printing uses a vat of liquid resin with a see-through, flexible film bottom. With LCD printers this sits directly on top of an LCD screen, with DLP printers the vat sits on top of a piece of glass with a mirror below at 45 degrees with a projector unit which projects the image onto the mirror which transfers through the glass to the bottom of the vat . A build platform is lowered down into the vat of resin (these models print from the top-down), very close to, but not touching the film at the bottom of the tank. The screen/projector lights up a silhouette image of the layer needed and the UV light from the image cures the resin above the illuminated pixels. The cured resin adheres to both the build platform and the film. Once the layer is cured (between 1 and 30 seconds depending on machine and resin used), the build platform slowly lifts straight up, peeling the cured resin away from the film, then is gently lowered back down again, stopping a fraction of a MM higher than the last time, and a new layer is formed. Each layer adheres to both the previous layer and the film and when the build platform lifts it is peeled off the film. The forces involved with pulling each layer from the film can be high so setting the print up correctly is imperative to avoid visible layers or delaminated layers. Sometimes, on peeling, the model is so firmly stuck to the film that it breaks away from the build platform and sticks instead to the film resulting in a print failure, so sometimes DLP printing can be quite frustrating for the user and the results can be sub-standard, however, once the settings and set up have been "dialled in", these failures can be avoided and the surface finish can be excellent.
*Sometimes also referred to as Digital Light Synthesis or DLS
SLA - Stereolithography
This type of 3D printing is widely considered to provide the most fine details and best surface finish of any 3D printing method. SLA printing uses a similar method to DLP but instead of a screen below the resin tank is has a laser which draws out each layer. This makes it a slower process (usually) than DLP printing but as there are no pixels involved, smoother curves can be achieved. The latest SLA printers have been designed with a "low force peel" system where the film at the bottom of the resin tank is gently peeled away from each layer rather than pulled away in one go, this gently peel removes much of the force from each layer, resulting in even fewer visible layer lines on the resulting print.
With both DLP and SLA printing, the size of the models that can be produces is limited to a relatively small build volume. Recently much larger DLP and SLA printers have been released but have yet to make their way into the model horse hobby. It is unlikely that larger scaled models will be printed for production for the foreseeable due to the longevity issues around larger, hollow models using these materials and also the clean-up time, which is currently much longer than with cast resins due to the sheer number of supports that would be needed on a bigger print.
SLS - Selective Laser Sintering
This is a very different method to those above. Instead of using a vat of resin, a vat with a build platform sits below a laser and a fine layer of plastic or metal dust is deposited onto the platform and then the laser draws out the first layer silhouette. The laser fuses (melts) the dust particles together to make a solid layer. The platform lowers a fraction of a MM and then a new layer of dust is deposited. Gradually the platform lowers into the tank and the tank fills with the powder. As the unused powder remains in the tank along with the 3D printed part, the part effectively floats in the unused powder and therefore no extra supports are required to hold it up, so SLS printed items are ready to go as soon as the unused dust has been blown/washed away. SLS printing uses very fine plastic or metal dust, so is largely an industrial application, far too messy and risky for home-use, however smaller SLS printers are coming into the market now although even they would need very careful handling to be used safely. Models produced via SLS printing have an almost velvety finish to them, dictated by the size of the particles in the powder used. They are often used in parts manufacture for cars and appliances as they can produce large, strong, (even metal!) usable finished parts but due to the grainy finish they aren't yet suited to the requirements of the model horse hobby. SLS printed models are used within the jewellery industry but these pieces are often heavily polished, so the grainy surface finish on raw prints is not an issue.
Polyjet
Another multi-material industrial manufacturing method, Polyjet printing can produce multi-material multi-colour models. Similar to an InkJet printer it sprays fine droplets of material onto a build plate and then exposes them to UV light to cure. Building bottom-up it sprays each layer directly onto the one below, then cures it and repeats to build up a model. Using multiple nozzles to jet the liquid material allows these printers to produce models with a range of materials in one piece (ie a plastic handle with a rubber grip), in a range of colours. The colours possible are in the millions, however they are limited to the nozzles used so photographic blending of colours is not currently mainstream in these types of printers/ Due to the price of these printers they are mostly limited to larger industrial applications, however with the speed at which 3D printing in all areas is moving, we can expect this technology to become more accessible in the near future. The finish on polyjet models is generally better than that of MJF type printers, however still not quite up there with the SLA type printers.
There are many different 3D printing technologies with more coming along all the time. One interesting one (though perhaps not quite for model horses yet) is Rapid Liquid Printing which injects print material into a gel, the gel suspends the material so gravity is not an issue and the results are very cool! Used in mostly furniture and lighting design, this technology has now found its way into the automotive industry with a lot of promise for pneumatic applications. Yet another method uses projected light to selectively cure gel using photons! I am particularly interested in this one as you can build around other objects - in this movie you can see they build a handle around a metal screwdriver, does this mean we could potentially use wire reinforcements in future model horse creation?
3D printing is not limited to miniature models, as it is the term used for any manufacture method using an automated additive process, it is also used in much larger applications such as boat-building and even construction! 3D printing has even made its way into the gourmet dining industry with chocolate, vitamins and even pancakes being produced this way!
MJF - Multi-Jet-Fusion
I love this type of 3D printing and feel we will be seeing far more of it in the model horse hobby very soon! Basically similar to SLS printing in that is uses powder rather than liquid resin or melted plastic, but with MJF printing, instead of a laser that melts the powder, a bonding agent (glue) is printed onto the powder to make the layers. Not only does this give a finished model with no supports to clean (yey!), the bonding agent can be coloured just like ink, making it possible to print a coloured model using the full spectrum on one model! You sometimes see "minime" scanned people printed this way, where the skin tone and clothes colours are printed direct with the model for a fully coloured print straight from the 3D printer. MJF prints have more visible print artifacts (ie layer/voxel lines) than SLA and some DLP prints, however if you click the images below you can see that even these stablemate scale models are easily good enough to pit against other OF or commercial models.
MJF is another fast-moving technology designed for miniature models, so they are improving the finish quality and recently announced the ability to produce full colour miniatures for war-gaming type collectors. This is a real game changer for the miniatures industry as a whole and I'm very excited to see more colourful models coming into our hobby. It's going to be a real headache for show-holders working out which division to put these unique, custom yet machine-created models in!
The models below were 3D printed using a Multi-Jet-Fusion 3D printer. They are not painted - the colours you see were a part of the 3D printing process itself, so, whilst the digital sculpture and the colour design were created by an artist (me!), the 3D printer brought them into the final physical form. I believe these are classed as OF models, though they could also be considered OF Resin, Commercial Resin or even Artist Resin by some - the decision on which division they should show in lies with the Show Hosts and ultimately (in the US) with NAMHSA.
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Casting V 3D Printing
With traditional casting methods, an original clay sculpture is moulded and copies cast using (in our hobby) liquid resin which cures to a hard plastic.
Check out the photos in the gallery below to see the process involved with resin casting. Click on each photo for more information:
Check out the photos in the gallery below to see the process involved with resin casting. Click on each photo for more information:
With 3D printing, you must have a digital model ready to print. There are two ways to get the original ready to print; scanning, or sculpting in a software package. You can buy digital models in many online stores such as Thingiverse to get you started, producing your own sculpted models can be more of a challenge - just as with physical sculpting, it is far easier working on an existing model (ie, a Custom) than starting from scratch (ie, an Original Sculpture).
Here is a gallery showing the processes involved with 3D printing from a scanned model, in this case we have Donna Chaney's "Rearing Andalusian" which was originally a clay sculpt, so had to be scanned in (we used a bone china cast as that was available at this time) and edited prior to printing. Click on the photos for a larger image and more information on the process used in this instance:
Here is a gallery showing the processes involved with 3D printing from a scanned model, in this case we have Donna Chaney's "Rearing Andalusian" which was originally a clay sculpt, so had to be scanned in (we used a bone china cast as that was available at this time) and edited prior to printing. Click on the photos for a larger image and more information on the process used in this instance:
As you can see, both resin casting and 3D printing methods require time and work to produce a clean final model. There are pros and cons to both, the main benefits of casting are with larger models, currently the main benefits of 3D printing are with smaller models, hence the abundance of 3D printed micro minis we are enjoying recently compared to very few larger scaled printed models.
3D Printing - What you need to know:
3D printed models - they're taking over!! 2019 and 2020 saw a massive surge in 3D printed models being sold into the model horse hobby which is continue in 2021, and you may feel a little overwhelmed by all the types and levels of quality out there. Here's a handy guide to help you navigate this new type of production. I've limited the information below to relevant printers and techniques; 3D printing is a very large subject, so the information below is currently the most relevant to our hobby in my opinion. All information is correct at the time of publication.
Quick guide - things to ask before buying a 3D printed model (all expanded on below):
What should I worry about when buying a 3D printed model? When buying any model horse we always have several things we look for. In plastic models we don't want to see seams, splits or scratches. On resins we don't want to see misalignment, exposed wires or bubbles, on china models we don't want to see flaws, cracks or crazing in the glaze. But what about 3d prints? Read on for a guide on what to look out for, what to worry about and what to love about 3D printed model horses!
Who sculpted this model? The first question is sometimes so obvious it doesn't get asked, but you always should! This is an important question, because a growing number of models being sold into the hobby now are actually re-creations of models by other artists. The first example of this was "Hawk" by Maggie Bennett, and also the skeleton model she produced for a while. This was all totally above board, transparent and acceptable, but I often see these models currently referred to as being sculpted by Maggie. In both cases, she DID do a tonne of work to make them suitable for production and rightly deserves the credit for her work, but the actual models were originally created by other people either by photogrammetry or digital sculpting. But recently more artists have printed and sold models that originated elsewhere (usually crediting the original artist, but not always), so be sure to do your homework and understand where the model originates from.
If taken from an existing clay sculpture (ie scanned and shrunk, minified etc), has the model been reworked to make it good for printing? This is certainly a buyer-beware question! Scanning models is as important as setting up the 3D print, it can be done well or it can be done badly. Either way, many models destined to be "minified" need a degree of re-working to enhance the details lost to scanning/shrinking and make for a better final result. Some don't - it depends on the sculptors style as to which subtle details may be lost, or become a bit... funny looking after the change in scale. Have you ever received a micro mini and you can't find the eye outlines? Or the ears may be so fine they break as soon as you touch them? These are examples of models that have not been correctly re-worked before production into mini form.
As an example from my own experience, the Copperfox micro mini pewter models had months of work done to them to redesign them for micro mini production. I am proud that I can confidently say that on each one you can clearly see the eyes, the muscles are still defined and the ears are both clearly visible and strong enough to be painted and packed for shows etc, but it took a lot of work to get them to work properly for Micro Mini scale production. There are many ways to "scan-shrink-print" but doing it well takes a thorough understanding of the processes and risks involved (pewter casting has its own challenges too which have to be catered for, but that's talked about on another page).
Quick guide - things to ask before buying a 3D printed model (all expanded on below):
- Who sculpted the horse? Sounds obvious, but is the seller the sculptor? Does the sculptor know their horses, anatomy, biomechanics and do they have the technical skills to apply this to the model in digital form (and did they sculpt from scratch, or start with someone else's model?!)
- If taken from an existing clay sculpture (ie scanned and shrunk, minified etc), has the model been reworked to make it good for printing? Simply scanning, shrinking and printing does not always make for the best quality result!
- Who set up and printed the model? Just like casting, printing quality depends heavily on the skills of the person doing it!
- What printer are they using? DLP or SLA, which brand, how old? These things matter and they're not overly complicated, read below.
- What settings were used? They may not divulge this but at least ask to see an actual print, not just a digital rendering of the model on offer.
- Which resin or resin mixture is the model printed with? So much variation!
- Who cleaned the model? who removed the supports and smoothed out any defects?
What should I worry about when buying a 3D printed model? When buying any model horse we always have several things we look for. In plastic models we don't want to see seams, splits or scratches. On resins we don't want to see misalignment, exposed wires or bubbles, on china models we don't want to see flaws, cracks or crazing in the glaze. But what about 3d prints? Read on for a guide on what to look out for, what to worry about and what to love about 3D printed model horses!
Who sculpted this model? The first question is sometimes so obvious it doesn't get asked, but you always should! This is an important question, because a growing number of models being sold into the hobby now are actually re-creations of models by other artists. The first example of this was "Hawk" by Maggie Bennett, and also the skeleton model she produced for a while. This was all totally above board, transparent and acceptable, but I often see these models currently referred to as being sculpted by Maggie. In both cases, she DID do a tonne of work to make them suitable for production and rightly deserves the credit for her work, but the actual models were originally created by other people either by photogrammetry or digital sculpting. But recently more artists have printed and sold models that originated elsewhere (usually crediting the original artist, but not always), so be sure to do your homework and understand where the model originates from.
If taken from an existing clay sculpture (ie scanned and shrunk, minified etc), has the model been reworked to make it good for printing? This is certainly a buyer-beware question! Scanning models is as important as setting up the 3D print, it can be done well or it can be done badly. Either way, many models destined to be "minified" need a degree of re-working to enhance the details lost to scanning/shrinking and make for a better final result. Some don't - it depends on the sculptors style as to which subtle details may be lost, or become a bit... funny looking after the change in scale. Have you ever received a micro mini and you can't find the eye outlines? Or the ears may be so fine they break as soon as you touch them? These are examples of models that have not been correctly re-worked before production into mini form.
As an example from my own experience, the Copperfox micro mini pewter models had months of work done to them to redesign them for micro mini production. I am proud that I can confidently say that on each one you can clearly see the eyes, the muscles are still defined and the ears are both clearly visible and strong enough to be painted and packed for shows etc, but it took a lot of work to get them to work properly for Micro Mini scale production. There are many ways to "scan-shrink-print" but doing it well takes a thorough understanding of the processes and risks involved (pewter casting has its own challenges too which have to be catered for, but that's talked about on another page).
Even digitally created models (ie sculpted from scratch on a computer, no clay involved) have challenges when being produced in different scales - a model that looks fabulous as a traditional scale 3D print might look bland and lose all definition as a micro mini, SM or Venti. On the other hand, 3D print a model designed to be a micro mini in a larger scale and you might laugh at what comes out! Simply scaling up or down and hitting print is not the best way to produce a model in several scales, but reworking the model at each scale takes more time and effort, so it's good to know if it's been done or not when investing in a model that's in a new scale.
This is why it is always SO important to see an actual printed copy of the model before parting with your money, particularly with a new sculptor or a printing artist you've not bought from before, as printed models often turn out quite different to the rendered image you saw taken from the digital sculpture (but we all use those because they do make the model look awesome!), hopefully they are different in a good way, but you just don't know until you've seen it printed!
Here you can see the difference between a rendered image taken from the digital model, and the same model 3D printed. The printed model in the photo is a print of the digital model shown, but the details are more visible on the render than the photo - the render is prettier (and I would argue more attractive) but the photo is a more accurate representation of what you would receive. I like to think the model in the photo is up to the standards expected by the discerning collector and I used the photo below to sell this model, but I have also used rendered images to help illustrate my models. Renders are fine, but always check the photos too!
This is why it is always SO important to see an actual printed copy of the model before parting with your money, particularly with a new sculptor or a printing artist you've not bought from before, as printed models often turn out quite different to the rendered image you saw taken from the digital sculpture (but we all use those because they do make the model look awesome!), hopefully they are different in a good way, but you just don't know until you've seen it printed!
Here you can see the difference between a rendered image taken from the digital model, and the same model 3D printed. The printed model in the photo is a print of the digital model shown, but the details are more visible on the render than the photo - the render is prettier (and I would argue more attractive) but the photo is a more accurate representation of what you would receive. I like to think the model in the photo is up to the standards expected by the discerning collector and I used the photo below to sell this model, but I have also used rendered images to help illustrate my models. Renders are fine, but always check the photos too!
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Who set up and printed the model? These days the original sculptor is rarely the person printing the copies for sale. Just as with traditional resin casting, there are good and bad examples. I would always refer to Rayvin here, as she is the epitome of GOOD 3D printing, she has done a tonne of research and experimentation to ensure her printed models are the best possible. I'd like to think my own models are also of such a high standard, but I'll let you be the judge of that. Sadly at the other end of the scale you have printing artists (ie the person setting up the print) who are more interested in making models fast and getting them sold en mass than in providing good quality. Unfortunately nobody would ever admit that, so it is up to you as a buyer to know who printed your model and which team they're on, whether they are being sold by the artist or another person.
What type of printer are they using? This is a perfectly valid question to ask your printing artist and they should answer you without hesitation. I won't claim that certain printers are better or worse, as so much of the process comes down to the skills of the person setting things up, but knowing who uses which printers will help you to understand which ones offer the qualities that you prefer.
What settings were used? This question may actually go unanswered if you ask it, as the specific settings printing artists use are often a rather closely guarded secret. It can take quite a lot of hard work finding out the best settings for your particular machine, and the time-investment isn't something that is easily given away freely. It's always worth an ask though, as certain settings are quite commonly used and knowing some of them is handy. The main setting for 3D prints is "how many microns", this is the thickness of the layers used to print your model. Anything over 50 microns (or 50μm) should be avoided, however further details all depend on multiple factors (ie a 50 micron print from a Form 3 is very different to a 50 micron print from an Anycubic Photon). Arm yourself with all the information possible and you stand the best chance of getting what you are expecting.
Which resin or resin mixture is the model printed with? This is a MASSIVE question, especially with DLP printers. Standard DLP printing resin can be very brittle, it can warp, discolour and make for a very disappointing experience! However, with just a few drops of certain additives it can be strengthened and given that tiny bit of flexibility needed to make it robust enough for all we put our models through. Again, a printing artist may be very reluctant to tell you their specific recipe as these have to be developed and take a lot of time investment, but they will probably be happy to share with you the base resin so you have an idea of what to expect. I won't list good and bad resins here as I've not used a DLP printer for a while and materials are developing so fast I wouldn't know which are currently best. SLA printers on the other hand have rather fewer resin options, but the resins available are far more highly engineered and as a result cost much, much more (for me it's £150/$180 a litre vs £30/$36 a litre for a typical DLP resin). They have to use very specific settings and processes but generally result in better overall properties. I will caveat this and say that a well mixed recipe of DLP resins can certainly give a model just as strong as an SLA print, just be cautious that claims of super-strong prints you can thrown around without damage can actually also mean they're slightly bendy!
Who cleaned the model? Just as important as the sculptor and printing artist, is the person responsible for getting the model finished and beautifully smooth ready for you to prep and paint. 3D printed models don't have mould-seams like cast resins do (yey!) BUT they do have other challenges. The first one being the removal of all evidence of the support structures from the printing process and a constant challenge to do quickly enough to be able to continue selling (this is why I can't release as many new models as I'd like as I am both sculptor and printing/cleaning artist for the bulk of my models). This is a laborious process and hard to get super-clean, it is the main bottle-neck in my own production process and I'm constantly trying to find local help to expediate things! But done well you should receive a model that is practically ready to paint, which is awesome! Done badly (or worse, not at all!) and you'll be spending far more time on your model than you would on a resin or pewter cast.
For the sake of simplicity I'm going to focus on the most common types of printers being used in our model horse hobby, and the main model type we're seeing, which are generally micro mini in scale and produced in resin.
What type of printer are they using? This is a perfectly valid question to ask your printing artist and they should answer you without hesitation. I won't claim that certain printers are better or worse, as so much of the process comes down to the skills of the person setting things up, but knowing who uses which printers will help you to understand which ones offer the qualities that you prefer.
What settings were used? This question may actually go unanswered if you ask it, as the specific settings printing artists use are often a rather closely guarded secret. It can take quite a lot of hard work finding out the best settings for your particular machine, and the time-investment isn't something that is easily given away freely. It's always worth an ask though, as certain settings are quite commonly used and knowing some of them is handy. The main setting for 3D prints is "how many microns", this is the thickness of the layers used to print your model. Anything over 50 microns (or 50μm) should be avoided, however further details all depend on multiple factors (ie a 50 micron print from a Form 3 is very different to a 50 micron print from an Anycubic Photon). Arm yourself with all the information possible and you stand the best chance of getting what you are expecting.
Which resin or resin mixture is the model printed with? This is a MASSIVE question, especially with DLP printers. Standard DLP printing resin can be very brittle, it can warp, discolour and make for a very disappointing experience! However, with just a few drops of certain additives it can be strengthened and given that tiny bit of flexibility needed to make it robust enough for all we put our models through. Again, a printing artist may be very reluctant to tell you their specific recipe as these have to be developed and take a lot of time investment, but they will probably be happy to share with you the base resin so you have an idea of what to expect. I won't list good and bad resins here as I've not used a DLP printer for a while and materials are developing so fast I wouldn't know which are currently best. SLA printers on the other hand have rather fewer resin options, but the resins available are far more highly engineered and as a result cost much, much more (for me it's £150/$180 a litre vs £30/$36 a litre for a typical DLP resin). They have to use very specific settings and processes but generally result in better overall properties. I will caveat this and say that a well mixed recipe of DLP resins can certainly give a model just as strong as an SLA print, just be cautious that claims of super-strong prints you can thrown around without damage can actually also mean they're slightly bendy!
Who cleaned the model? Just as important as the sculptor and printing artist, is the person responsible for getting the model finished and beautifully smooth ready for you to prep and paint. 3D printed models don't have mould-seams like cast resins do (yey!) BUT they do have other challenges. The first one being the removal of all evidence of the support structures from the printing process and a constant challenge to do quickly enough to be able to continue selling (this is why I can't release as many new models as I'd like as I am both sculptor and printing/cleaning artist for the bulk of my models). This is a laborious process and hard to get super-clean, it is the main bottle-neck in my own production process and I'm constantly trying to find local help to expediate things! But done well you should receive a model that is practically ready to paint, which is awesome! Done badly (or worse, not at all!) and you'll be spending far more time on your model than you would on a resin or pewter cast.
For the sake of simplicity I'm going to focus on the most common types of printers being used in our model horse hobby, and the main model type we're seeing, which are generally micro mini in scale and produced in resin.
DLP vs. SLA
So now you have an idea of the process, but what about all these different printers and different resins etc? I've covered the various printing methods at the top of the page, but I can simplify it a little here as there are currently just two main types of printing technologies used in the model horse hobby; DLP and SLA.
(I'm conveniently skipping Hartland's FDM printed models for this article for the moment until I can expand on it, they use a totally different type of printing [FDM] for their lovely iridescent prints)
DLP printers have a screen that sits directly under a flat tank (vat) of liquid resin. The bottom of the tank is clear to allow light through from the screen, this clear membrane is called a FEP sheet and it is very strong and slightly flexible. A flat build plate is lowered into the resin down to the bottom of the tank, with just a fraction of a millimeter between it and the FEP. The screen lights up the first slice/layer of the print, it shines ultraviolet (UV) light up through the FEP and onto the thin layer of resin between the FEP and the build plate, curing (hardening) it which also sticks it to both the FEP and the build plate. The build plate then lifts up, peeling the printed layer away from the FEP sheet. The printed layer is stuck solid to the build plate, which is important as it will need to stay there while every following layer is printed and peeled away - which involves some pretty strong forces! During printing with DLP printers, you can hear the FEP sheet as it stretched and snaps back against the screen with a "pop"!
Common examples of DLP machine brands include Anycubic, Phrozen, EPAX, Elegoo, Wanhao and Creality
The biggest benefits of DLP printers are the price, they have become more and more affordable and are getting better and better in quality. The earlier versions of these printers (going back just to just 2017!) used 2K screens. This refers to the number of pixels the screen has. If you think about your TV and how we've gone from standard definition up to HD, then UHD (4K) and now even 8K, the same thing is happening with printers. 4K printers are now common, which means they have four times the number of pixels to the original 2K printers (twice as many across, twice as many down). Just as with your TV, more pixels means a clearer image. In 3D printing terms, when there are a lower number of pixels available, the printed model can get what can look like little rings showing on the sides of the model, usually with horses these manifest most on the belly as is has the most subtle round-ness and is a larger flatter area than on the finer details. These rings are called "voxel marks" or "voxel rings". 4K printers will have finer voxel rings vs. 2K printers as they have a higher resolution so should have a smoother finish. Voxel marks are usually minimal and normally will disappear under primer, but be aware of this as they may require a little sanding, especially if from a 2K printer. In mid-late 2021 6K and even 8K printers are coming available. They tend to be the larger machines so the pixels are still spread across a larger screen, but when smaller 8k machines come out, the fine-ness of the pixels should eradicate all but the most subtle voxel marks. Advancements are being made to reduce layer lines on prints from the newer printers too, so it is an exciting time in terms of finish quality for these printers.
Click on the image below to see an example of a (primed) model printed on an older 2K machine, exhibiting an extreme display of voxel rings - these are not layer lines but marks left by the pixels on the screen. For illustrative purposes only - newer 3D printers are WAY better than this now and even older 2K printers have had software updates and can use AA (see the circles illustration below)!
I would love to add a photo of a model printed on a 4K printer if possible but I don't own one - contact me if you have any I could use here!
(I'm conveniently skipping Hartland's FDM printed models for this article for the moment until I can expand on it, they use a totally different type of printing [FDM] for their lovely iridescent prints)
DLP printers have a screen that sits directly under a flat tank (vat) of liquid resin. The bottom of the tank is clear to allow light through from the screen, this clear membrane is called a FEP sheet and it is very strong and slightly flexible. A flat build plate is lowered into the resin down to the bottom of the tank, with just a fraction of a millimeter between it and the FEP. The screen lights up the first slice/layer of the print, it shines ultraviolet (UV) light up through the FEP and onto the thin layer of resin between the FEP and the build plate, curing (hardening) it which also sticks it to both the FEP and the build plate. The build plate then lifts up, peeling the printed layer away from the FEP sheet. The printed layer is stuck solid to the build plate, which is important as it will need to stay there while every following layer is printed and peeled away - which involves some pretty strong forces! During printing with DLP printers, you can hear the FEP sheet as it stretched and snaps back against the screen with a "pop"!
Common examples of DLP machine brands include Anycubic, Phrozen, EPAX, Elegoo, Wanhao and Creality
The biggest benefits of DLP printers are the price, they have become more and more affordable and are getting better and better in quality. The earlier versions of these printers (going back just to just 2017!) used 2K screens. This refers to the number of pixels the screen has. If you think about your TV and how we've gone from standard definition up to HD, then UHD (4K) and now even 8K, the same thing is happening with printers. 4K printers are now common, which means they have four times the number of pixels to the original 2K printers (twice as many across, twice as many down). Just as with your TV, more pixels means a clearer image. In 3D printing terms, when there are a lower number of pixels available, the printed model can get what can look like little rings showing on the sides of the model, usually with horses these manifest most on the belly as is has the most subtle round-ness and is a larger flatter area than on the finer details. These rings are called "voxel marks" or "voxel rings". 4K printers will have finer voxel rings vs. 2K printers as they have a higher resolution so should have a smoother finish. Voxel marks are usually minimal and normally will disappear under primer, but be aware of this as they may require a little sanding, especially if from a 2K printer. In mid-late 2021 6K and even 8K printers are coming available. They tend to be the larger machines so the pixels are still spread across a larger screen, but when smaller 8k machines come out, the fine-ness of the pixels should eradicate all but the most subtle voxel marks. Advancements are being made to reduce layer lines on prints from the newer printers too, so it is an exciting time in terms of finish quality for these printers.
Click on the image below to see an example of a (primed) model printed on an older 2K machine, exhibiting an extreme display of voxel rings - these are not layer lines but marks left by the pixels on the screen. For illustrative purposes only - newer 3D printers are WAY better than this now and even older 2K printers have had software updates and can use AA (see the circles illustration below)!
I would love to add a photo of a model printed on a 4K printer if possible but I don't own one - contact me if you have any I could use here!
So, why are newer DLP printers better than older ones? There are two reasons: Firstly, newer printers have higher-resolution screens, so as more pixels are available each pixel is smaller, giving a finer finish. Secondly, Anti-Aliasing has more recently become a brilliant feature that can have incredible results when dialled in right (older 2K machines can use AA now thanks to software/firmware updates from the manufacturers, so 2K printer owners can now get better results than those shown on the black model above).
You may be familiar with antialiasing in terms of photographic images, where instead of nice smooth curves you have to make do with pixels which can give a choppy, jagged edge to curves when cropped or zoomed in. Antialiasing is the way that the pixels are blended to soften the hard edges, giving a smoother appearance. The same is happening with the DLP printers; jagged edges are softened by exposing them to less UV light, literally making them softer so they blend into each other giving a smoother finish. AA can also be used to help blend the layers together making it three dimensional, so used correctly the results can be phenomenal.
I've illustrated this below, it's rather an extreme example but it shows how DLP printers solve the voxel issue by using anti-aliasing.
Left: Vector circle (unaffected by pixels but impossible for a DLP printer to translate), Centre: Pixelated circle, no antialiasing, Right: Pixelated circle using antialiasing (higher settings yield more shades of grey and therefore smoother results).
You may be familiar with antialiasing in terms of photographic images, where instead of nice smooth curves you have to make do with pixels which can give a choppy, jagged edge to curves when cropped or zoomed in. Antialiasing is the way that the pixels are blended to soften the hard edges, giving a smoother appearance. The same is happening with the DLP printers; jagged edges are softened by exposing them to less UV light, literally making them softer so they blend into each other giving a smoother finish. AA can also be used to help blend the layers together making it three dimensional, so used correctly the results can be phenomenal.
I've illustrated this below, it's rather an extreme example but it shows how DLP printers solve the voxel issue by using anti-aliasing.
Left: Vector circle (unaffected by pixels but impossible for a DLP printer to translate), Centre: Pixelated circle, no antialiasing, Right: Pixelated circle using antialiasing (higher settings yield more shades of grey and therefore smoother results).
Resins: DLP printers are steaming forward as higher resolution screens and more advanced software packages are being developed. The other part of the difference between DLP and SLA printers are the resins used. As the two types of machines have different ways for projecting UV light into the resin to cure it, they require resin that responds to the light in different ways and so the two types of printer require two different types of resin. DLP resin is quite easily accessible, it is inexpensive and is available in a myriad of different colours and types, with some being very strong and rigid and some softer and more flexible. Generally, printing artists will mix a recipe of these resins and additives to find the best balance of strength and flexibility, some may use a single resin type which may (or may not!) be the best for the job, so it is always worth asking the printing artist what they are using - some may guard their recipes as it can take a long time and lots of experimentation to develop them, but they should be able to offer some insight into the particular traits of the resin recipe they are using.
SLA resins are generally more expensive (up to 10x more!) and are not normally able to be mixed. This is not actually a bad thing though, as these resins have been much more thoroughly engineered to provide the ideal properties for the intended use and therefore often out-perform DLP resins in terms of strength and flexural modulus (ie how far you can bend it before it breaks, so are more likely to bounce and survive!).
I will not say that either type of resin is better than the other, as a well-mixed recipe of DLP resin can be almost indestructible, just be sure to check that your printing artist has a good handle on this if they are using a DLP printer, even if they are using SLA it is worth asking which resin they use, as some are more suitable than others for the specific item being produced.
SLA resins are generally more expensive (up to 10x more!) and are not normally able to be mixed. This is not actually a bad thing though, as these resins have been much more thoroughly engineered to provide the ideal properties for the intended use and therefore often out-perform DLP resins in terms of strength and flexural modulus (ie how far you can bend it before it breaks, so are more likely to bounce and survive!).
I will not say that either type of resin is better than the other, as a well-mixed recipe of DLP resin can be almost indestructible, just be sure to check that your printing artist has a good handle on this if they are using a DLP printer, even if they are using SLA it is worth asking which resin they use, as some are more suitable than others for the specific item being produced.
SLA printers also known as "the expensive ones" easily cost 10x the amount basic DLP printers can. Whereas DLP printers are aimed towards hobby markets, SLA printers often take years to develop and refine and are usually sold into more professional and even industrial areas. SLA printers use similar principles to DLP, but with a few important differences.
Common examples of SLA machine brands include Formlabs, B9 and Moai
In a similar way to DLP printers, SLA printers also have a build plate that lowers into a tank (vat) of resin with a transparent bottom. These printers, however, don't have a screen; they have a laser instead. The laser "draws" out the sliced image using strong UV light onto the bottom of the resin vat and fills it in using a hatching method (like colouring in with a pencil). This means that laser prints can take longer than DLP prints, certainly when multiple models are concerned, but as the laser moves in a vector motion (ie smoothly, like the left-most circle above), there are no voxel marks. SLA printers still use layers to build up the model, the silhouette is drawn between the build plate, peeled away from the tank bottom and repeated, however, modern SLA machines use a "gentle peel" motion, where the resin tank is gently tilted and flexed so the printed layer peels slowly and without the suction forces that make DLP prints "pop" away from the tank bottom. The combination of the laser and this "low force peeling" reduces the layer lines we associate with 3D prints to almost invisible levels (providing you get the settings right!), though with ANY 3d printed item, you'll be able to find them if you look closely enough.
Click on the image below for a typical SLA printed model - you won't see voxel rings, you can see layer lines if you look closely enough, but primer alone would smooth any remaining visible lines away.
Common examples of SLA machine brands include Formlabs, B9 and Moai
In a similar way to DLP printers, SLA printers also have a build plate that lowers into a tank (vat) of resin with a transparent bottom. These printers, however, don't have a screen; they have a laser instead. The laser "draws" out the sliced image using strong UV light onto the bottom of the resin vat and fills it in using a hatching method (like colouring in with a pencil). This means that laser prints can take longer than DLP prints, certainly when multiple models are concerned, but as the laser moves in a vector motion (ie smoothly, like the left-most circle above), there are no voxel marks. SLA printers still use layers to build up the model, the silhouette is drawn between the build plate, peeled away from the tank bottom and repeated, however, modern SLA machines use a "gentle peel" motion, where the resin tank is gently tilted and flexed so the printed layer peels slowly and without the suction forces that make DLP prints "pop" away from the tank bottom. The combination of the laser and this "low force peeling" reduces the layer lines we associate with 3D prints to almost invisible levels (providing you get the settings right!), though with ANY 3d printed item, you'll be able to find them if you look closely enough.
Click on the image below for a typical SLA printed model - you won't see voxel rings, you can see layer lines if you look closely enough, but primer alone would smooth any remaining visible lines away.
Click on the photo below to see two prints: one was printed on a DLP printer, one on an SLA. Can you tell which is which? The quality is very similar! I should point out that both of these models are lovely and smooth, excellent examples of 3D printing at today's standards, I used very strong lighting and a macro lens to highlight the layer lines/rings. With the right settings, superb results can be achieved from almost any printer. With the right resin mixture these models could also have similar properties in terms of tensile and flexural strength.
You can read more about DLP v SLA prints here: https://formlabs.com/uk/blog/resin-3d-printer-comparison-sla-vs-dlp
Here are a few pros and cons compared between DLP and SLA printers:
Here are a few pros and cons compared between DLP and SLA printers:
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DLP - Pros and Cons
Pros: Lower purchase price Lower consumables price Speed, especially on prints with multiples A wonderful array of colour and effect possibilities Small batch colours, easy swapover between resins Cons: Older machines can produce heavy voxel marks Layer lines can be quite visible if not tuned in well enough Takes a lot of experimentation to find the best resin recipes If poor resin recipe used, models can be weak |
SLA - Pros and Cons
Pros: Smoothest surfaces currently possible No voxel marks Materials have best qualities "out of the bottle" Materials are consistent Cons: Costs are very high, not realistically accessible for hobbyists Often slower, especially for prints with mutiple models Limited colours and effects (no pearls or glow in the dark, boo!) Small batch resin use is restrictive, limiting the fun factor and ability to experiment. |
The main reason 3D printed models have finally exploded into our hobby is that the visible layer lines have now been reduced to a point (when set up correctly) where a thin coat of primer will lead to a nice smooth finish, which at the end of the day is what we all want! Some (but not all!) printers have finally reached this important milestone, provided the sculptor and printing person both did their jobs right, of course!
So what happens when the person setting up the print DOESN'T get it right? Possible issues are heavily visible layer lines, support contact points in strange places, ie the eyes, nostrils, hooves (if detailed), in fact anywhere where it detrimentally affects the sculpture. Prints that aren't set up with correct support placement and number can have missing parts, wavy surfaces, and even delaminated areas (splits/cracks). Prints that aren't rotated correctly can have layer lines in inconvenient areas, much more visible than they may have been had the model been orientated more carefully. Resin choices/mixes that are unsuitable can lead to very fragile, brittle, weak models that break easily, or even models that are rather bendy!!
Below you can see three models printed at different settings, they're just trimmed so please ignore the support bumps for this illustration. Click on the image for a larger view. It's quite obvious to tell which was at the lowest (worst) settings! Which one would you say is printed at the highest settings? The model printed at the highest settings is actually the one to the right, but notice the strange shine it has, with what looks like grid lines on it. Cranking the settings up to the highest level is NOT always the answer to getting the best results. To be fair the highest settings should provide a the best print, but in the world of model horses where surface finish is so important, at some scales the super-smooth shiny finish can become a problem during prepping as any sanding will cut into it and then look patchy against the shiny finish of the untouched areas, not to mention the fact that this setting costs a great deal more in terms of consumable costs, so the most-often used settings for this printer and this scale of model is the more balanced settings used in on the middle model.
So what happens when the person setting up the print DOESN'T get it right? Possible issues are heavily visible layer lines, support contact points in strange places, ie the eyes, nostrils, hooves (if detailed), in fact anywhere where it detrimentally affects the sculpture. Prints that aren't set up with correct support placement and number can have missing parts, wavy surfaces, and even delaminated areas (splits/cracks). Prints that aren't rotated correctly can have layer lines in inconvenient areas, much more visible than they may have been had the model been orientated more carefully. Resin choices/mixes that are unsuitable can lead to very fragile, brittle, weak models that break easily, or even models that are rather bendy!!
Below you can see three models printed at different settings, they're just trimmed so please ignore the support bumps for this illustration. Click on the image for a larger view. It's quite obvious to tell which was at the lowest (worst) settings! Which one would you say is printed at the highest settings? The model printed at the highest settings is actually the one to the right, but notice the strange shine it has, with what looks like grid lines on it. Cranking the settings up to the highest level is NOT always the answer to getting the best results. To be fair the highest settings should provide a the best print, but in the world of model horses where surface finish is so important, at some scales the super-smooth shiny finish can become a problem during prepping as any sanding will cut into it and then look patchy against the shiny finish of the untouched areas, not to mention the fact that this setting costs a great deal more in terms of consumable costs, so the most-often used settings for this printer and this scale of model is the more balanced settings used in on the middle model.
So that is 3D printing in the hobby as it currently stands, in a nut-shell.
The difference between models at each end of the quality scale with 3D printing can be astonishing! So always refer back to the list at the top of this page when inquiring about a 3D printed model you want to buy. You don't always need to aim for models at the very top end though - there are benefits to models throughout the scale just as there are with plastic, resin and china models. As long as you make an informed choice and know what to expect from your chosen artist/printer, you can look forward to receiving a model you can appreciate for all its best qualities!
The difference between models at each end of the quality scale with 3D printing can be astonishing! So always refer back to the list at the top of this page when inquiring about a 3D printed model you want to buy. You don't always need to aim for models at the very top end though - there are benefits to models throughout the scale just as there are with plastic, resin and china models. As long as you make an informed choice and know what to expect from your chosen artist/printer, you can look forward to receiving a model you can appreciate for all its best qualities!
I bought a 3D printed model, how do I look after it?
Yey! You have a new model from your favourite artist, and it is 3D printed!
"But what's all this I've heard about keeping them in the dark? Should I be worried?"
3D printed models are just as tough as cast resin models but have a few differences you need to know. You won't find wires reinforcing 3D prints, because it's not actually possible to insert a wire during printing. Provided it is a suitable SLA resin or a good DLP "recipe" and printed at the correct settings, it is stiffer than cast resin so you won't get any sagging later down the line. On larger 3D prints, these are printed hollow, some warping can occur during curing so a horse with four feet down may wobble a little if it is larger and hollow, which is nothing to worry about so long as it has been completely washed and dried inside and you protect it from further UV exposure.
The sun: 3D printing resin is all about UV exposure. During printing intense UV light solidifies the resin. Afterwards, during post-curing it also strengthens it. After that the process is complete, however, further exposure to UV light would continue to harden the resin and if too much UV exposure occurs, the model would become so hard it gets brittle and could even crack! Normal sunlight inside a house is much lower than the intense light used during printing, but it is still a low dose, and day by day it can gradually affect the model and the resin may continue to cure beyond the perfect point, and ultimately it could become brittle. In bright direct sunlight this could happen in just a few days, but a model kept in a very shaded area could be displayed for weeks without over-curing.
To avoid damage from sunlight there are a few things you can do. Display your model in a very shady spot in your display case. Coat your display case glass with a UV protective film (this is a great thing to do regardless as it also protects against fading of paintwork or yellowing of cast resins, I highly recommend this!). You can keep the 3D printed model packed away until ready to paint (such a shame to do this though), or you could simply paint it! The sealers used during painting, and even the paint itself protects the resin against UV light, therefore halting the curing process and protecting your model into the future, and if you prefer to keep your model unpainted, then a few light coats of a UV protecting sealer spray will also do a great job protecting it!
"But what's all this I've heard about keeping them in the dark? Should I be worried?"
3D printed models are just as tough as cast resin models but have a few differences you need to know. You won't find wires reinforcing 3D prints, because it's not actually possible to insert a wire during printing. Provided it is a suitable SLA resin or a good DLP "recipe" and printed at the correct settings, it is stiffer than cast resin so you won't get any sagging later down the line. On larger 3D prints, these are printed hollow, some warping can occur during curing so a horse with four feet down may wobble a little if it is larger and hollow, which is nothing to worry about so long as it has been completely washed and dried inside and you protect it from further UV exposure.
The sun: 3D printing resin is all about UV exposure. During printing intense UV light solidifies the resin. Afterwards, during post-curing it also strengthens it. After that the process is complete, however, further exposure to UV light would continue to harden the resin and if too much UV exposure occurs, the model would become so hard it gets brittle and could even crack! Normal sunlight inside a house is much lower than the intense light used during printing, but it is still a low dose, and day by day it can gradually affect the model and the resin may continue to cure beyond the perfect point, and ultimately it could become brittle. In bright direct sunlight this could happen in just a few days, but a model kept in a very shaded area could be displayed for weeks without over-curing.
To avoid damage from sunlight there are a few things you can do. Display your model in a very shady spot in your display case. Coat your display case glass with a UV protective film (this is a great thing to do regardless as it also protects against fading of paintwork or yellowing of cast resins, I highly recommend this!). You can keep the 3D printed model packed away until ready to paint (such a shame to do this though), or you could simply paint it! The sealers used during painting, and even the paint itself protects the resin against UV light, therefore halting the curing process and protecting your model into the future, and if you prefer to keep your model unpainted, then a few light coats of a UV protecting sealer spray will also do a great job protecting it!
I hope you have found this article useful, I do plan to expand it when I can with illustrations and more information as it becomes available. If you would like to support this research please scroll to the top of this page.
Disclaimer. All information in this article is produced by me and is based on my own experience and research. Any errors are unintentional and will be happily rectified once highlighted to me. Contact me if you see anything here that is incorrect or you feel I should change.