Production Questions: Mold Reuse, Age, and Breakage?

[Neverchosen]

Hey all, 

In the Rumour thread I responded to a post by @jeremym on the subject of Mold Breakage. I was curious as to the exact process in which a mold breaks. Is it a case of overall deterioration, literal breakage, or some mixture between the two? Is this a less significant problem with plastic models as opposed to finecast/resin?  When they do those limited releases of old models are they molds on their final legs?

I suppose a secondary question is whether there are digital files for any of the older models, and if not could they be scanned by GW and converted into a different medium? For example: I would love a return of the Hellcannon in plastic but I also feel like we would be more likely to get a new sculpt.

 

To make the question more discussion worthy are there any models that you would like to see return in either AOS or in the Old World? Any you would rather not see return?

Edited December 30, 2020 by Neverchosen

[Overread]

I've not done casting but I've picked up afew things over the years

1) Resin and Metal have cheaper machines to cast with and cheaper moulds when they are produced. It's why whilst metal (and perhaps resin) are more expensive base materials; they are more popular for start up firms because the costs for plastic casting and moulds are very very high. 
 

2) All moulds used for casting degrade over time, each time they are used creates wear and tear on the mould. Don't forget they get heated up and cooled down and material pushed into them every time. Metal and resin moulds do break quicker than plastic ones, but as they are cheaper to replace they still wind up affordable for many firms. 
 

3) Different models will wear a mould differently. Those with more fine details and with certain shapes can cause more wear and tear as the models are removed each time. Privateer Press had to remove one model (that I'm aware of) because the model kept spoiling its mould too fast for it to be economically viable to produce. 

4) Masters are used to create new moulds, in theory so long as you've retained your master copies you can create new moulds. I would assume any popular models might have more than one master made and kept for insurance against wear and tear on the master over time or damage/loss of the master. 

5) You can actually see wear and tear even on plastic. New models will typically have very fine and hard to see mould lines; whilst older and more worn moulds will have more defined mould lines. This is why some very old sculpts can appear to be of worse quality; however sometimes they get an updated mould and suddenly appear to jump in quality after a certain point. However this is rare as typically for plastics when a new mould is really needed enough time has passed that GW might well just redesign the model. 

6) When GW did their new Adepticus Titanicus line they did 3D scan the models. They also had to measure with micrometers every part of the models to provide scale and context for the scans. It's a lot of work to take a current design, scan and produce a quality model. Though as a tech that's advancing right now its likely something that is coming down in costs and for AT they were redesigning to a new scale; whilstif you were making like for like it might be a quicker process. In theory GW could scan old designs to keep an archive, but I've a feeling its not something they would do. A few specialist items perhaps, but by and large I'd wager they keep masters and moulds in storage, but on old models once its broken its broken and gone (they've actually had that happen - a cast-to-order run of old Dark Elf models had the Morathi on Pegasus model removed early because the mould broke and they didn't have a master to restore from). 

7) I believe GW keeps most masters/moulds, but I've a feeling they have had purges over time and removed some from their inventory.

[Neverchosen]

Thank you @Overread,

That was very informative. It also settles a lot of the conflicting messaging I have read regarding The Old World. It also explains why my memory of many of the 6th edition models seemed much more defined.

I do hope they find a way of safely restoring some of my old favourites. However, it seems more economical and better for posterity to just create a newer sculpt.

 

Does this mean that models like Be'lakor and Lord Kroak are at greater risk due to age and material?

Edited December 30, 2020 by Neverchosen

[ian0delond]

Also there is only so much mold they can use at a time in their factories. They have to plan a  rotation and make stocks. Sometime a mold is not estimated to be worth coming back to the rotation compared to every other one so the models are oop.  But because the mold are still useable they can do those Made to Order campaigns they can use the molds knowing exactly how much are going to be sold. So little to no overproduction for better margins.

For similar profitability reasons some broken molds  are never replaced.

[zilberfrid]

I can also vaguely remember that harder plastic wears molds out quicker. GW uses very hard plastic.

[Overread]

2 hours ago, ian0delond said:

Also there is only so much mold they can use at a time in their factories. They have to plan a  rotation and make stocks. Sometime a mold is not estimated to be worth coming back to the rotation compared to every other one so the models are oop.  But because the mold are still useable they can do those Made to Order campaigns they can use the molds knowing exactly how much are going to be sold. So little to no overproduction for better margins.

For similar profitability reasons some broken molds  are never replaced.

Rotating out models is normally more of a Forgeworld thing than a pure GW thing; I'm sure it happens at GW, but models there have to keep up with the rules so its more the exception if one were rotated out like that. 

More typically models are designed to rotate out sometimes or to rotate in with replacements etc.... 

1 hour ago, zilberfrid said:

I can also vaguely remember that harder plastic wears molds out quicker. GW uses very hard plastic.

Actually I'd say GW's plastic is a softer plastic compared to some other miniature producers. Hawk Wargames and Privateer Press have both used a tougher plastic. Hawks I'd hazard actually holds greater fine details as well. 

 

You might be well be right, but that would be comparing plastics to plastics in terms of moulds wearing out. 

 

[Ggom]

For resin models, one thing you will observe over time is “shrinkage” of models. This is most obvious when you have large multipart models (eg. Large resin tank) - some of the pieces will just appear slightly too big or slightly too small. From what I have gleaned, this happens because resin moulds have pretty short lifespans, and FW will create new moulds using existing “masters.” However, over time, as you get to latter generations of the moulds, the size difference becomes appreciable. This is, apparently, what leads to the frustrating scenarios where your spartan door is too big for the frame, or some wall section is too long, etc. This is sometimes confused with warping of the resin, which also happens, although warping is easily solved by heating the resin, adjusting the warped part, and cooling it back down.

Regarding computer assisted design, or CAD - in previous years GW and FW sculpted the traditional way (greenstuff, milliput) to create the master sculpts. It is unlikely they would have files for those masters, and the existence of moulds would be based on what gets created from the master sculpt(s.) More recently years, I hear they have switched over to CAD sculpting - this has advantages and drawbacks as well. Obviously they have the files stored digitally, so things are likely easier to organize and catalogue. I imagine it allows them to do really clever things with optimizing the sprue layout as well, aligning mould lines with natural edges on the model, etc. Some slight drawbacks here (IMO) might be more stylistic, and may not be related to the technology. Personally, I dislike some of the new CAD sculpts - see for instance the Heresy Night Lords jump pack praetor (CAD) vs the original Heresy Night Lords raptors (hand sculpted.) The older sculpts had much finer details around cloth, thin lines, filigree, etc. CAD seems to make everything “chunkier.” I may be mistaken, and this might just be a change in overall art direction or new sculptors.

I will also second @Overread - mould lines seem to get worse with the age of the sculpt. This appears to be true with resin as well. Getting a FW kit on release is often much nicer than getting a FW kit 5 years later. I speak from personal experience with some godawful mould lines on my marines hahaha. That being said, resin is easy to work with once you get the hang of it, its very malleable with heat, and I’d say alot of people give it a bad rep without having spent time learning how to work with it. 

[Overread]

I think one of the drawbacks of digital design is the lack of hands-on with the model itself. I think its made the industry (and not just GW) do things that were very hard to very time consuming to impossible with traditional sculpting methods. However it also means that we get models which are perhaps not as stable/structurally sound or as easy/functional to paint. Because now they can layer details and parts over each other; they can make khinerai fly on their tails and such. They can achieve some really awesome sculpts, but at the same time we can lose some practicality aspects. 

 

Style also certainly comes into it, I'd wager that CAD has no issues with fine detail now, but some of the sculptors might just have different styles. There are also things with casting that rear their heads and some of the more dynamic poses might require less detail in some regions to cast well.

 

Certainly software lets them play with sprue- old sprue were veyr spaced out, modern ones are chock-a-block with parts and almost no wasted space. In addition the cuts have become far more complex - Slaanesh fiends area great example where they've some very creative cuts which almost manage to hide almost all the join lines on the models - which is honestly very impressive work. GW has some very skilled people in the industry in parting. 

[Evangelist of Cinders]

Edit:apologies for the many errors english isn't my first language and can falll apart when I get into technical things.

I'm going to try to give some answers  as someone who has some hobby and professional casting experience. I use to caste lead toy soldiers as a kid(this was a real thing kids use to do and i inherit a simple casting set from my great uncle with some molds), i studied and worked as a metallurgist and a machinist off and on for about 15 years now covering bronze age techniques to modern ones using 3d printers( though not the same tech as GW). The material science i m going to be kinda glossy on cause some things i m not too sharp on and others are trade secreats.

 

Starting with the simple lead mini of your this is the simplest usually a sculpt is made as a master( carve it, greenstuff, miliput whatever) and this is pressed into a ceramic(or other industrial material such as steel and carbon coke) mold using usually a hydraulic press or similar tool. At this point some tooling may be used to carve out details in the mold but unless you got someone really good with an eye for it probably just  have the  mold put straight into production. The master can often be damaged right here in this process and be gone for good.(a similar method is done by resin sculpting hobbyist) You now just pour white metal into the mold till heat, or wear and tear cause a crack or carving leading it yo break(but like i said earlier white metal and a good mold can last a century but your limits by luck and what form you can carve as some will just guarantee a break simpler soft shapes most likely to last) the simplest form you can see this wear and tear is the mold lines on older designs. This is the method most scene by blackmarket re casters using a Original sprue as the master with zero to lil tooling done to improve the mold they make.

Now this is a limited process, most industrial white metals sky rocketed in cost in the 90s and we tend to frown upon lead toys. Most have switched to plastic which tends to use molds at lower heat but weaker material(not like glass vs steel but enough to make a difference when scaled up production level).  Either material you dont really wanna just rely on a crucible and a steady hand to produce your line. So most manufacturers use probably injection or spin casting(or something akin to it their is stuff like raising casting but it relies on similar principles). With injection the machining of the mold is paramount cause if the shape isnt done right the material wont fill the mold no matter what(this was probably the cause of much of the notorious fine cast flaws in the early days as it was a whole new way of tooling molds for GW). This leads to more complicates and worked molds leading to higher chances of a nick or dent that will eventually break the mold. Many mini companies use a spin process where a wheel of molds is made and spun using the centrifugal force to push the hot material into the mold again you can see how wear and tear would be likelier then my coke covered ceramic mold and casting sand. 

I should note this does not always mean a degrading quality over time I can definitely tell for example without looking at production numbers for example my bretonnian sprues got better in quality after a new mold was made the master is the same design of course but clearly the tooling and machining of the mold led to sharper detail. The design remained the same but the team at the factory or design level(it can vary from company to company) either got better tools or better practice(or less management oversight) and were more willing to spend time machining a mold to allow better details in casting

Which brings me to 3d printers now professionally I am somewhat limited in my experience as they are something I mostly either order masters from a catalogue and it comes to me printed ready for a single casting(we use em for lost wax casting a method where you keep detail by having the molten metal fill the space the master is pressed in) or its some custom thing a customer designed on a shop front software. Very often however (especially the custom stuff) breaks easily or even in mold. As the designs are often made with only the 3d model in mind not the tooling or casting process let alone the material concern(thin bands, or a mold that structurally cant hold form in softer metals).  Part of the price of the convenience of 3d design is the material structural needs of actually printing a master which is different from those of casting it.(less so with CNC machine designs and lathes but id bet these arent used much in the GW processs)

 

Now some tooling and fixing can be done but it can often be not worth it for us production wise for a few reasons. Primarily you need the right eye and good skill to solve the issue not good for mass production.  Materially cause the mold would need to be tooled for every cast, the master doesn't hold form in the shape it was machined/printed in we can usually tell before hand and send it back to the designer.

 

Now in jewellery i can negotiate if a custom piece or mold fail and still make a single version similar with hand tools and torch.  No company that produces minis can do that. I already work for a company that does a lot of production(I'm on the more one on one customer end but still probably have 150-300 pieces go through my workbench a day) and we try not to produce molds unless we have too cause it ends production at some level. there are a lot of technical differences between methods used but the general principle of wear and tear is hopefully explained well enough. Couple the every day problems with mass scale like GW does and i hope ive shed light onto what may be behind some decisions they make productionwise.

 

 

Edited December 31, 2020 by Evangelist of Cinders

[Shearl]

While I can't add much to the discussion regarding plastic injection molding other than reiterating that they're rather hardy and expensive, I can chime in briefly on silicon molds used for casting resin. 

Both in my own small scale experiments casting with silicon molds and with resin miniatures from Forge World, the silicon is prone to tearing after repeated use. This is further hastened as a result of resin producing heat as it cures (this is part of the reason some recommend using dental plaster in some casting applications).

On several occasions I've been assembling a Forge World miniature when I've noticed a stray bit of turquoise silicon stuck into one of the nooks or crannies, signifying that any future miniatures coming out of that mold will simply be missing detail there. But the flip side here is that while silicon molds last much shorter than plastic injection molds, they are far cheaper to replace.

[zilberfrid]

17 hours ago, Overread said:

Actually I'd say GW's plastic is a softer plastic compared to some other miniature producers. Hawk Wargames and Privateer Press have both used a tougher plastic. Hawks I'd hazard actually holds greater fine details as well. 

You might be well be right, but that would be comparing plastics to plastics in terms of moulds wearing out. 

Ah, that's my limited knowledge of miniatures then.

My Renedra products (Renedra, Warlord, Northstar), Wizkids and Blacklist and most of my boardgame minis are all softer than modern GW (older GW, being the mid-'90's Bretonnian Bowmen, Empire Knights and Bretonnian knights are as hard as modern Renedra).