What is a retool?
Discussion
Just thinking about this at the weekend, and a quick google hasn't really enlightened me- what is a retool, how does it relate to the original moulds, and what is the difference between that and a new kit- for example are any dimensional inaccuracies able to be corrected.
Are there really cost and time advantages in retooling - I assume that the work is all done in CAD?
Are there really cost and time advantages in retooling - I assume that the work is all done in CAD?
My understanding is that a retool is just that - brand new molds. Most injection molds have a certain shelf life, after which the detail on any produced parts begins to suffer and you experience flashing. It's quite an investment, both in time and money to produce new ones so companies generally will use them as long as possible. By retooling they can also, like you say, make improvements or changes to make them more desirable.
It's actually a bit ambiguous as a term. Sometimes it really does mean what it says, a refining or alteration of an already existing set of moulds.
In more recent years it has come to mean a brand new tooling (i.e. a completely new set of moulds) to replace an old set of moulds that are worn or considered obsolete in some way.
In the past, Airfix did literally "re-tool" old moulds. An example of this would be their 1/72 Gloster Javelin. This started life as a Heller kit and depicted the Javelin T3 variant. The Heller T3 was also boxed by Airfix. However, after a short period, Airfix literally amended the Heller moulds to turn the kit into a Javelin FAW9.
They also converted the tooling for the 1/144 Vickers VC10 airliner into an RAF tanker version.
In more recent years, Airfix have been replacing some of their older moulds with brand new replacements - such as the mid 1970s 1/72 Messerschmitt 109E and Hurricane MkI being replaced by completely new toolings a couple of years ago..
In more recent years it has come to mean a brand new tooling (i.e. a completely new set of moulds) to replace an old set of moulds that are worn or considered obsolete in some way.
In the past, Airfix did literally "re-tool" old moulds. An example of this would be their 1/72 Gloster Javelin. This started life as a Heller kit and depicted the Javelin T3 variant. The Heller T3 was also boxed by Airfix. However, after a short period, Airfix literally amended the Heller moulds to turn the kit into a Javelin FAW9.
They also converted the tooling for the 1/144 Vickers VC10 airliner into an RAF tanker version.
In more recent years, Airfix have been replacing some of their older moulds with brand new replacements - such as the mid 1970s 1/72 Messerschmitt 109E and Hurricane MkI being replaced by completely new toolings a couple of years ago..
Rubymurray said:
My understanding is that a retool is just that - brand new molds. Most injection molds have a certain shelf life, after which the detail on any produced parts begins to suffer and you experience flashing. It's quite an investment, both in time and money to produce new ones so companies generally will use them as long as possible. By retooling they can also, like you say, make improvements or changes to make them more desirable.
Shelf life? The moulds wear through use, not storage.oobie38 said:
Just thinking about this at the weekend, and a quick google hasn't really enlightened me- what is a retool, how does it relate to the original moulds, and what is the difference between that and a new kit- for example are any dimensional inaccuracies able to be corrected.
Are there really cost and time advantages in retooling - I assume that the work is all done in CAD?
Out of interest, where did you see the term used?Are there really cost and time advantages in retooling - I assume that the work is all done in CAD?
My take on it, which may be nonsense, is a re-tool is using the bolsters and ejection system from an old mould and creating new cavity inserts to create a modified or updated model, or if the original cavity inserts are worn out. Such as the javelin mentioned above, or the Blackburn na39 which was modified into the buccaneer. We don't do that any more as it is more cost effective to just create a complete new mould tool, and it's very hard to mate new CAD designed parts to parts that were pantographed years ago from a 3:1 pattern (with only very basic 2d drawings to reference, the patterns are long lost). It also means you are stuck with the same parts breakdown as the layout of the parts on the frames would have to match exactly.
lufbramatt said:
My take on it, which may be nonsense, is a re-tool is using the bolsters and ejection system from an old mould and creating new cavity inserts to create a modified or updated model, or if the original cavity inserts are worn out. Such as the javelin mentioned above, or the Blackburn na39 which was modified into the buccaneer. We don't do that any more as it is more cost effective to just create a complete new mould tool, and it's very hard to mate new CAD designed parts to parts that were pantographed years ago from a 3:1 pattern (with only very basic 2d drawings to reference, the patterns are long lost). It also means you are stuck with the same parts breakdown as the layout of the parts on the frames would have to match exactly.
I guess it depends on the context of where the O/P read it - which is why I asked. I seem to recall Arthur Ward in one of his Airfix books, mentioned lost tooling for some models (IIRC a tractor & SAM missile?) and re-tooling in that context meant replacements. I think I also read in some Dapol instructions (for a railway crane) that they'd bought the old Airfix moulds and re-furbished them. I may have got the Airfix link totally wrong, but I was surprised they mentioned it at all in the instructions. I'd class refurbishment and re-tool as different, but...context. I don't think there can be a right or wrong, unlike "new-tool".
Definitely. The ex-airfix railway kits were originally Rosebud Kitmaster IIRC, so they've been around the block a few times. When they refurbished those moulds I expect they kept the cavity inserts, but fitted new ejector pins, mould bushes (so the two halves of the mould are aligned better) welded up any corrosion, re cut the feed gates and re ground the mating surfaces of the tool to reduce any flashing. Probably a couple of £k worth of work per tool, any more and you may as well just make a whole new mould, although those kits are lovely with lots of retro appeal.
lufbramatt said:
Definitely. The ex-airfix railway kits were originally Rosebud Kitmaster IIRC, so they've been around the block a few times. When they refurbished those moulds I expect they kept the cavity inserts, but fitted new ejector pins, mould bushes (so the two halves of the mould are aligned better) welded up any corrosion, re cut the feed gates and re ground the mating surfaces of the tool to reduce any flashing. Probably a couple of £k worth of work per tool, any more and you may as well just make a whole new mould, although those kits are lovely with lots of retro appeal.
OK. I also seem to remember something about them using reduced injection pressure to make the moulds last a bit longer? Mine was the Booth Radley crane, which I was (am) going to use for a seaplane lifting diorama. The fit of parts was superb.They may be running the moulds a bit hotter to make the plastic flow better (can only do small batches though as the ejector pins will start binding) or mixing some ABS in with the styrene which has the same effect but is more expensive. They may also have rebuilt the inserts into lots of small tools rather than one big one (lots of the old injection moulds from that era are massive- with lots of frames all in the same tool which needs lots of pressure to fill properly but leads to flashing over time). Smaller tools are easier to balance the pressures and can be run on smaller, cheaper machines.
Lots of things they can do to improve the moulds to suit their production processes, it's a bit of a black art, I love going and chatting to our moulders!
Lots of things they can do to improve the moulds to suit their production processes, it's a bit of a black art, I love going and chatting to our moulders!
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