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I notice that with a new dark apostle model coming soon, the old Finecast model is no longer available. Although, I understand that Finecast was unpopular, it seems a shame that players will still be limited to one official option from the Games Workshop store. I wonder why as well as producing updated models in plastic, why don't they also keep the old sculpts and produce those in plastic as well? Is there something about models that were sculpted with resin in mind that makes them unsuitable for plastic moulds?

 Ginjitzu wrote:
Is there something about models that were sculpted with resin in mind that makes them unsuitable for plastic moulds?

No, not particularly. Cost might be a factor though.

No, you can't. Plastic models are injection-moulded in steel moulds. Resin and metal models are cast in rubber/silicone moulds. It's an entirely different process. Even the processes for making the moulds themselves are entirely different, and you can't just 'copy' a rubber casting mould to make a steel injection mould for the same model.

 Duskweaver wrote:
No, you can't. Plastic models are injection-moulded in steel moulds. Resin and metal models are cast in rubber/silicone moulds. It's an entirely different process. Even the processes for making the moulds themselves are entirely different, and you can't just 'copy' a rubber casting mould to make a steel injection mould for the same model.

But doesn't every mould, regardless of the material, come from an original sculpt? My question isn't whether the old resin moulds can be used to make new plastic models, but whether the original sculpt can be used to make new moulds.

 Ginjitzu wrote:


But doesn't every mould, regardless of the material, come from an original sculpt? My question isn't whether the old resin moulds can be used to make new plastic models, but whether the original sculpt can be used to make new moulds.

Yes, i guess it's entirely possible, if the master sculpt is in a good condition. On the other hand producing the (steel) mould is the expensive part in model creation...

Plastic models need to be carefully design for the injection moulding process.

When sculpted by hand they used to create a “3-up” that was used to cut the mould via a pantograph, so that the detail was captured as the machinery reduced the size. Now they sculpt in CAD and split the models into parts via computer, to beat utilise space and hide seams.

You’d get a very poor result trying to injection mould a figure designed for a silicone mould, and that’s if it even popped out of the mould after casting! Under and overhangs and detail without a release angle would probably scupper your efforts.

GW doesn't use masters anymore. They design their models on the computer (including how they are assembled from small parts), and these files are used directly to create the molds.
At least that's the process for current plastic minis, I don't know how they create their resin ones (like the commissar that came out not long ago).

It's a little confused as sometimes it not clear if A product is GW or FW, with special lemited edition mini's. (However GW now seems to finally be moving over to everything is plastic.

GW has plastic and Finecast model's and moulding
FW had resin models and moulding.

Plastic is good for high volume repeatable process working
Finecast is done in some weird method that seams to require insane numbers of gates.

FW resin production is a less repeatable process, also tends to be relatively inefficient in terms of time and materials.

Taking a product from one production method to another usually requires a resculpt of the miniture.

CAD or physical, 3-up or actual size isn't the issue.

The main issue is undercuts. See this blog article (from Steve Buddle who now designs for GW) for a proper explanation, but basically the silicone moulds for resin and metal models are flexible, so minor undercuts aren't a problem as the mould flexes when you remove the models. Large undercuts can cause damage to the moulds or miniatures, which is why a lot of one-piece models will have pouches, holsters, clothing, etc, filling in gaps. Moulds for polystyrene models, however, are made from metal, and can't flex. This means you can't have any undercuts at all. If you try and make a plastic version of a metal model, you'll need to fill in all the undercuts. For any old-timers here, look at the painting guides for old GW games like 1st edition Space Hulk, Space Crusade, Heroquest or Advanced Heroquest. The painted models on the boxes will be the metal or resin prototypes, which are more detailed than (and have slight differences to) the final plastic models.

One minor example of this is the studs on the left shoulder of mk6 Marine armour. On a metal model, those studs will all stick straight out from the surface of the shoulder pad. On the plastic RTB01 models, they all point in the same direction, perpendicular to the plane of the mould (which makes the ones at the sides rather distorted). The same is still visible to a lesser extent on the current plastic Tactical Squad models.

This is one of the reasons that GW's new plastic models come in so many odd-shaped bits - it's to allow for details in all directions on the final assembled model. They can do this because the CAD/CAM software automatically works out the required cuts rather than relying on the designer or mould maker.

The softer plastic such as the PVC material used in Reaper Bones models and all sorts of modern board games, doesn't have this problem to the same extent as that plastic will deform to allow it to be removed from the mould, so it's easier to take models sculpted for metal or resin and convert them to this material (which is how Reaper started out with Bones).

IIRC, the resin models are also designed using CAD, and then master models are 3D printed. Those printed models are then used in place of "greens" to create master and production moulds as has always been done

Ice_can wrote:
It's a little confused as sometimes it not clear if A product is GW or FW, with special lemited edition mini's.

All of FW's miniatures are FW resin (the exception being the hybrid plastic kits). The majority of GW kits are plastic, but will say in they description if they're not (Severina Raine is "Citadel resin" while Techpriest Enginseer 2 is metal, for example).

The original FIneCast was an attempt to use metal molds with resin, and wasn't exactly successful. GW now tend to only use resin for small batch miniatures where they can't justify the cost of a metal mold.

Finecast isn't a material (I've had plenty of Forge World models that feel identical to Finecast), it's a manufacturing process. Essentially, metal models are spin-cast (the moulds are spun at high speed; molten metal is poured in the centre then centrifugal force forces it outwards through the mould cavities. This forces it into the extremities better than relying on gravity and fluid pressure alone) while resin is vacuum-cast (the moulds are filled from the top - the big wedges that Forge World parts come attached to are the pour funnels - and then placed in a vacuum chamber one or more times to "suck" out any bubbles of gas in the liquid resin).

Finecast was an attempt to spin-cast resin models. After all, GW had a load of spin-casting machines they suddenly weren't using, so it was worth a try. The extra sprue and gates and "shards" of resin are apparently needed to help the resin flow into the extremities properly. Whether they've got better at it over the last few years or if they've abandoned the process and gone back to something more traditional now that the number of ex-metal models in the catalogue has reduced I don't know.

I can't tell what Finecast is or isn't, but it's certainly not the same as FW resin, FW casting and QC could be improved but I've yet to get FW stuff that's been half as bad as some of the evilness that is Finecast, some of it's good and looks the same but some if the Finecast stuff I've seen has been like it's finished in textured paint, or like rubber. I don't know enough about the process and materials to be able to say for sure what and why, but FW resin and Finecast certainly seems to generate some wildly different results.

 Ginjitzu wrote:

 Duskweaver wrote:
No, you can't. Plastic models are injection-moulded in steel moulds. Resin and metal models are cast in rubber/silicone moulds. It's an entirely different process. Even the processes for making the moulds themselves are entirely different, and you can't just 'copy' a rubber casting mould to make a steel injection mould for the same model.

But doesn't every mould, regardless of the material, come from an original sculpt? My question isn't whether the old resin moulds can be used to make new plastic models, but whether the original sculpt can be used to make new moulds.

It wont work, those resin molds are not built in a way that works with how plastic ones are made to.

Someone "can" make them work for sure, but it wont come out well, more mold lines, more holes, more air bubbles, and some parts wont get filled.

Can it be done?
Probably
is it not worth the cost?
Probably

Plastic molds are very expensive and if you don't expect to sell enough to make back the most of the mold its not worth doing.

Master models would be still necessary for resin sculpts.
You can often find leftovers of the rubber mold when you buy FW models. I had a few stuck in between Machaius's Tank track links.


For plastic, all you need is a 3D model of the entire sprue.
That is then machined into a 2-piece steel block that serves as a complete injection mold.
Those molds can be very expensive, depending on the size, level of detail and the way they are machined.
Nowadays usually by CNC milling, and when you need tiny details, then electrical discharge machining would be the best (but costly and lengthy) way.

 Ginjitzu wrote:
I notice that with a new dark apostle model coming soon, the old Finecast model is no longer available. Although, I understand that Finecast was unpopular, it seems a shame that players will still be limited to one official option from the Games Workshop store. I wonder why as well as producing updated models in plastic, why don't they also keep the old sculpts and produce those in plastic as well? Is there something about models that were sculpted with resin in mind that makes them unsuitable for plastic moulds?

Could it be done? -Yes, but there would be a lot of rework and engineering that would have to be done to produce these older models in plastic and in the process the master would be so altered it wouldn't look exactly the same.

The biggest challenges with reproducing the models in plastic are undercuts and draft angles. Resin/Finecast/Pewter casting all use flexible and semi-flexible molds, this allows pieces to have slight undercuts and allow parts to sit in the mold in angles that aren't possible with plastic molds.
When a part comes out of an injection mold it has to lift straight out, since the metal mold isn't going anywhere or flexing.

There are two ways GW could approach this if they wanted to reproduce older models in plastic. Old fashioned way requires they go through a particular method of casting to get a 3 times larger copy of the miniature, which they could then clean up and cut it to parts, then use a special stylus to trace across the surface of the model to machine the mold. The other way would be to digitize the original model, clean that up then, then cut the model into parts adjusting part orientation and adding draft angles where necessary as they build out the sprue. At the end their mold designer would run an analysis to determine pressure and temperature settings and if any adjustments are needed to ensure the correct flow of molten plastic. An EDM tool is produced and used to cut into the mold base and produce the cavities.

At the point in which you're ready to produce the model in plastic, it will require you to have done more work than sculpting it from scratch.

I heard that with Kharn, they did in fact scan the original model in and use that as a guide for the sculptor to produce a whole new sculpt.

 Ordana wrote:
Can it be done?
Probably
is it not worth the cost?
Probably

Plastic molds are very expensive and if you don't expect to sell enough to make back the most of the mold its not worth doing.

I don't think material cost is the issue here, as GW invested heavily into being able to produce their own injection moulds.

The issue is that they'd be forced to remodel the entire thing just to make it work as an injection mould, and then you'd have to sell an old model in a new material - which people won't buy as much as if you'd gone and remade the model from scratch, especially not if you sell it for a "new model price" instead of the old pricing (eg going from 15 to 25 € for a single HQ). Which means it's also down to production cost, but not the manual / material one - you'd simply invest designer time into something that'll sell way worse than if you'd just started a new design from scratch.

The increase in HQ price seems to be because of moving to plastic.

This makes sense: dies for the injection machines are incredibly expensive compared to those for metal and resin models, and since any individual is likely to only buy one instance of a given HQ character, they need to sell them for more to make a profit on them; especially compared to an infantry kit which any individual will probably buy several dozen times at least.

 Ginjitzu wrote:
Is there something about models that were sculpted with resin in mind that makes them unsuitable for plastic moulds?

Undercuts.

Dies for plastic injection molds are very carefully designed pieces of machinery. you cant just put any shape you want into two pieces of steel and expect anything good to come out of it.

hell depending on the surface area, perfect cubes are also difficult. most parts need to be at an angle to allow parts to be released properly.

mind you GW and a lot of other companies have been getting way better with cad designs to allow for some very complex parts. they could potentially redesign existing kits fully from the ground up to look basically the same if they really wanted to but realistically they wont outside of nostalgia kits, as there is no reason to invest a ton of money into a kit that many people may already have models for.

Though speaking of plastic injection molding and resin, there was some formlabs ads showing them making prototype plastic injection molds out of 3d printed resin that was super interesting.

 Inquisitor Lord Katherine wrote:
The increase in HQ price seems to be because of moving to plastic.

This makes sense: dies for the injection machines are incredibly expensive compared to those for metal and resin models, and since any individual is likely to only buy one instance of a given HQ character, they need to sell them for more to make a profit on them; especially compared to an infantry kit which any individual will probably buy several dozen times at least.

True, but it's hard to argue that the same sculpt, but done in plastic, is worth that much more even if the increase is reasonable due to the costs involved. Making a new sculpt of the same hq unit and selling that for more than the older one is much more palpable to us customers,isnt it? And that translates directly into more sales.

I mean I passionately hate metal models, but I still wouldn't be happy paying 25€ for the old Primaris Psyker sculpt just to have it made from plastic. A new modern sculpt would tempt me to buy one, though. (note:I'm talking about the imperial guard HQ psyker here, not a space marine)

nekooni wrote:
I mean I passionately hate metal models, but I still wouldn't be happy paying 25€ for the old Primaris Psyker sculpt just to have it made from plastic. A new modern sculpt would tempt me to buy one, though. (note:I'm talking about the imperial guard HQ psyker here, not a space marine)

So does it tempt you? -

beast_gts wrote:

nekooni wrote:
I mean I passionately hate metal models, but I still wouldn't be happy paying 25€ for the old Primaris Psyker sculpt just to have it made from plastic. A new modern sculpt would tempt me to buy one, though. (note:I'm talking about the imperial guard HQ psyker here, not a space marine)

So does it tempt you? -

Spoiler:

That one isnt out yet, is it? But yes, it's on my wishlist for sure. Fingers crossed for it being cheaper than 25 €, but let's be honest... I'd pay it.

nekooni wrote:

beast_gts wrote:

nekooni wrote:
I mean I passionately hate metal models, but I still wouldn't be happy paying 25€ for the old Primaris Psyker sculpt just to have it made from plastic. A new modern sculpt would tempt me to buy one, though. (note:I'm talking about the imperial guard HQ psyker here, not a space marine)

So does it tempt you? -

Spoiler:

That one isnt out yet, is it? But yes, it's on my wishlist for sure. Fingers crossed for it being cheaper than 25 €, but let's be honest... I'd pay it.

It's part of a box set for a board game. She won't be cheap. :(

The secret to GW's model quality really comes down to the fact they own their own equipment and do the sprue cuts themselves. It's built up a knowledge base that lets them design around the limitations of the material. You can really see it in the easy build stuff, where really dynamic sculpts with small part counts are made possible with some really clever layering. You definitely can't take a resin model and just make it in plastic because of this. Resin's big advantage is that it does large chunks of model well. That's why PP loves it so much; it goes well with their "skipped leg day" aesthetic. Translating a large chunk of resin into a sprue is no easy feat if its not a box shape, which is why that style is so common in GW vehicles and why the things they actually do in resin tend to have more curves to them.