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Question about recasting toys


SuperDimensionalDave

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I am completely ignorant about and devoid of any ability to make recast parts. :huh: I am however the proud owner of a few custom resin recast pieces (and soon a JM from Rohby) from members of this community and am happy with them. I do however see the flaws in them when compared to the original toys they are installed on or next to. Such as more fragility and being more brittle compared to the original plastic. Well my wheels were turning here this evening and I was wondering why nobody makes recast parts in plastic like the original toys? I'm sure there is a reason but I was wondering why? Is it just not economically feasible or just too difficult to do out of one's garage? I'd love to make custom toys so I wanna know more! Can any of you expert recasters enlighten me?

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I don't mean entire toys, anything. Parts that are already being recast such as 1/55 heads, fast packs or the item that really got me thinking about it, the BP8 backpack hinge for the 1/48 Yamato bird. A plastic recast would have to be stronger than a resin one.

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Good question. Answers, recasters?

I'm probably guessing that resin is easily casted and more liquid than say....plastic. Plastic probably has to be what they say....injected or something with pressure. I'm just talking outta my ass. Let a pro explain.

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I used to work in the plastics industry, so I can say for sure that its plain and simply the cost of making the item is WAY too prohibitive any other way.

The plastic the toys use is called polystyrene. Polystyrene needs a special machine, called an injection molder, to force it into a special built metal mold. A small injection molder can be found used for, oh say a couple of thousand dollars. Add on to that the hundreds of dollars needed to have a mold machined and well you get the picture.

This is why so many toy companies are not willing to make toys that won't have a decent selling run. Just to produce one single toy a company may have already spent several thousand or more dollars in design, research and mold creation.

Resin, which is the casters poision of choice, on the other hand requires no special expensive tools. Recasters can use silicone rubber to make their own molds, and they don't have to have an expensive machine like the injection molder to cast the parts into the mold.

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To create parts made of plastic like the original toy's (ABS, polystyrene, polypropylene, nylon, acrylic, etc.) requires much more than what the average recaster can muster.

To recast a part, you use the original to create a RTV mold and either pour a polyester or epoxy based resin in the mold, or inject the resin with a disposable syringe; those with more elaborate set-ups will employ a pressure chamber to collapse air bubbles or a vacuum chamber to eliminate trapped air altogether. If there are castable resins with more plastic-like resilience I'm not familiar with them.

In order to work with manufacturing grade plastics, you need manufacturing level equipment:

Steel or Aluminum molds must be created with ejector pins to push out finished parts from the mold, cooling lines to keep mold temperatures within optimal range, cams and lifters for intricate detail, etc. All this requires a great deal of engineering and manufacturing. First you'd need to scan the desired part with a 3D scanner, then the mold halves have to be designed around it and everything mentioned above that may be necessary must be included; this would be most often accomplished with some form of 3D engineering software. Once the mold is designed, you have to make it with CNC and other methods. Once you have the molds cut they have to be polished, etched, etc.

Now that you have a finished mold that will probably have cost anywhere from a few thousand dollars to tens of thousands or even over one Hundred Thousand dollars depending on mold complexity, size and material, you will need an injection molding machine that can handle the mold and all its associated equipment, as well as the granulated plastic of your choice (note that the choice of plastic affects the design of the mold due to the physical properties of the material, specially its shrinkage rate); you'll also need a small warehouse to house it all.

There is a growing molding segment called rapid tooling that utilizes RP molds instead of metals. RP molds are usually created through the use of Stereo Lithography. This cuts down on the cost of the mold itself, but everything else is still a factor, and the mold is only good for a few hundred to a couple of thousand parts at most.

Phew! That was a long winded answer that basically says that "recasting" in plastic is not feasible for the person doing small volume stuff.

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well for a high quality toy-I could understand a mold costing 10k

but how do the bootleg companies in hk and china do it?

The quality of their plastic is not as good as the originals, but it is still much sturdier than resin. And they sell their copies for dirt cheap-I don't see how they'd ever recoup the cost of an expensive mold?

S

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Much like pirated DVDs, they spent next to nothing on developing the product. Back in the days, they actually had to reverse engineer and create a new mold from an existing toy they're making a bootleg off. With all the toys being made in China these days, my guessi s that a lot of the bootlegs were cast from the very same molds that were casting originals - the factory simply ran a couple thousand extra "off the record" while no one's looking, or they'd make duplicates of the mold and make copies else where.

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Much like pirated DVDs, they spent next to nothing on developing the product. Back in the days, they actually had to reverse engineer and create a new mold from an existing toy they're making a bootleg off. With all the toys being made in China these days, my guessi s that a lot of the bootlegs were cast from the very same molds that were casting originals - the factory simply ran a couple thousand extra "off the record" while no one's looking, or they'd make duplicates of the mold and make copies else where.

Is that why they're so hard to pin down??

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I work in an automotive facility that uses injection molding and blow molding.

The basic reason you can't recast parts with higher quality plastics is because you need high temperature and pressure to inject the plastic. As was said previously you need special equipment to do this.

As for why the bootlegs are so cheap, it all comes down to quality. The quality of the toy and the quality of the molds they are using. Better quality is obviously more expensive. If you want a super accurate part then you would get a CNC cut steel mold. But for all we know the bootleg companies could be using poor quality aluminum molds which are a hell of a lot cheaper but do not produce as good a part. There are also other issues such as production volumes, overhead, design and development, etc. that all affect piece price.

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another (lesser) point is time and materials....many of the recasters do this in their spare time in a smaller work area. Supplies and materials (and time ) needed to work with resin recasts are tiny compared to what it would take to run and manage a professional level injection machine and create the metal root molds needed for it. This is also not the mention fumes, and clean-up.

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