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Editor's Note: This originally came about because of the white testshots on ebay...the discussion revolved around whether these were more of the infamous, 'lunchtime Specials', and veered off into the specific plastic types used on tfs. It's a good read.
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Message: 14 Date: Thu, 31 Jul 2003 20:04:47 -0000 From: "Himawari" Subject: Re: My What the Crap Auction! (I want this thing!) Actually, that is a good idea! I'll just make a white tracks of my own! Except, I won't use polyurethane (PU). BTW, those figures that you made using resin from that place close to where you live, was it with polyurathane? I've been trying to find an epoxy that I can use, but everything winds up being too soft and even though we are working with a thermoset here, it has the same physical properties of a common thermoplastic: PVC. (sort of) I have found a very good theroset epoxy from Japan that sets and has the same characteristics of polycarbonate or even polystyrene or ABS. Of course I'm refering to the physical properties, not the chemical ones. I won't go as far as to say that it is similar in terms of relative density or tensile strength (MPa or psi), but overall look and strength and it is strong like the above three, yet not brittle like most polyurethanes you'd find from hobby shops or what have you. Most clear polyurethanes I have bought and tried are quite poor against sunlight. Even regular white cast may show signs of yellowing over time. Perhaps the biggest thing I miss to living in Japan is the ability to take a bicycle for 30min and go into town (the heart of it anyhow) and buy anything I need. Here, I'd go to a supplier of chemicals, and be lucky if they carry anything close to what I could by going to a HOBBY shop in Japan. Pretty funny really... But back to the topic, if the seller is really using cast resins to make those white parts, he would have to invest more into it than the $100 starting bid for each. There is the RTV silicon that he would have to buy, even the cheapest that I've seen in Japan is around $30 for 1kg for decent quality, and the casting resin if really high quality I'd imagine around $30 for 500ml. Epoxy would cost even more. On top of that, he'd have to buy each toy, and for him to do such a good job casting them, I'm sure he would have to own at least an oil pump ($350 for a decent one) and some type of bell jar or vaccuum chamber which would run around $100 at least. Of course, he may not have the pump and chamber, and might just be painting the cast or epoxy on the surface to show have a clean surface, and then doing another pour to fill the inside and tap the mold continuosly, but that would take experience and I don't think it would come from Joe blow with zero feedback. I think these are more of the same lunch time specials. It would be no cost to the person working at the plant. He loads the ABS or polystyrene into the hooper, add the pigment or color he chooses, it passes through the sprue and the runners, the mold injection machine completes it's cool down cycle and within a min, out pops the parts. When the machine starts up, or when a mold is removed and a new one placed in, of course they will do color test, and shrinkage tests etc, the workers have simply kept these peices instead of recycling them like they were suppose to. they don't pay a cent for the materials, and they can assemble them at home. In fact, they may even need to be assembled as part of the test to make sure of stress and shrinkage issues that could occur. Now let's say the person operates the machine and in charge of it's QC can decide what color plastic goes into the hooper, well he can say, let's just use a standard white this time... Thanks.
-Himawari |
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Date: Thu, 31 Jul 2003 19:40:00 -0400 From: "Mark Kimmel" Subject: Re: Re: My What the Crap Auction! (I want this thing!) I agree with Himawari there. I used to work at a plastics factory for a while (we used to make expandable polystyrenes and the resins that would go into your car dashboard skeletons. I like Himawari's guess about it being a Quality Control test sample. We used to have to run a few good test samples before our injection molders were up to snuff (we used to make the t-bone samples for the stress testing/tensiles as well). If its already being made for QC work (part of this could be heat/age testing), then it has a reason to exist and would be easier for "thieves" to come by. I.E. Thieves wouldnt have to fire up a molder and make each part one by one as those machines are pretty big and would be rather notceablewhen in operation if everyone else is at lunch...but...if a Tracks is already made for an aging study and they were done with the study, tracks could walk away MUCH EASIER imho. Ah - the chem eng degree I never use...:) Later, M
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Date: Fri, 01 Aug 2003 00:11:45 -0000 From: "Himawari" Subject: Re: My What the Crap Auction! (I want this thing!) Just out of curiosity, what are you doing now? Since it borders what I'm getting into. I've just paid and will start on my plastics engineering degree from this September at a very recognized technical school here in B.C. I've talked with the grads from the program, and most are offered jobs even before they finish, so some just drop out! To keep this semi transformer related, I find it interesting how most of the reissues are made with ABS and poycarbonate plastic, whereas before it was mainly just polystyrene. For fun, and out of curiousity, I did a flame and solvent test on an old and new transformer (parts actually) to conclude the difference in the plastics. It was quite interesting to see the floating black carbon pieces in the air from burning it. Thanks.
-Himawari |
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Date: Fri, 01 Aug 2003 18:21:56 -0000 From: "Bond. Estebond" Subject: Re: My What the Crap Auction! (I want this thing!) ---Himawari: Actually, that is a good idea! I'll just make a white tracks of my own! Except, I won't use polyurethane (PU). Yeah, I noticed you don't like the stuff! Back when you were writing about how to do a really good fake blue Bluestreak I realized you had an aversion to PU. BTW, those figures that you made using resin from that place close to where you live, was it with polyurathane? Yup, the stuff I use is polyurethane based. I have found a very good theroset epoxy from Japan that sets and has the same characteristics of polycarbonate or even polystyrene or ABS. Of course I'm refering to the physical properties, not the chemical ones. How hazardous is it to use? Do you need a commercial license to buy that kind of stuff? It sounds like the average consumer would have trouble finding something like that. Most clear polyurethanes I have bought and tried are quite poor against sunlight. I have yet to find a truly clear polyurethane that doesn't have a yellowish tint to it. Even regular white cast may show signs of yellowing over time. I figured it might, so that's why I paint everything. Dyeing after curing is the next approach I'm going to try. I can't get a good deep hue of any color no matter how much dye I add to the two part resin when I mix it. So I'm going to experiment with RIT dye as that seems to be all the rage lately in kitbashing circles. Perhaps the biggest thing I miss to living in Japan is the ability to take a bicycle for 30min and go into town (the heart of it anyhow) and buy anything I need. Here, I'd go to a supplier of chemicals, and be lucky if they carry anything close to what I could by going to a HOBBY shop in Japan. Yeah, I figured as much. On this continent they just don't take modeling as seriously as they do in east Asia. Pretty funny really... But back to the topic, if the seller is really using cast resins to make those white parts, he would have to invest more into it than the $100 starting bid for each. That's true, but once you have a mold made you can always cast more parts. So the initial investment is hard to offset selling just one piece, but if he makes multiples, then he gets back the cost of production after two or three units. If he's doing what I think he's doing, I'll bet he'll sell more of these white 'prototypes' once these take off. There is the RTV silicon that he would have to buy, even the cheapest that I've seen in Japan is around $30 for 1kg for decent quality, If he really is using RTV, I'm thinking he needed approximately 5 lbs/3 kg of the stuff to make the molds for all three figures. (I'm surprised that Skids doesn't look like it used as much plastic as a regular deluxe sized Autobot car-maybe that's why he chose it?) I could get 6 pounds of RTV for $120, so that's in the ballpark, but you're right that just the RTV alone would cost more than the asking price for one of these as he's selling them. and the casting resin if really high quality I'd imagine around $30 for 500ml. Epoxy would cost even more. With 500ml I think he could do all three at least once. So by my reckoning that's $150 investment for three figures, and that's assuming he casts all the parts perfectly the first time, and makes no mistakes when he makes the molds. So right there my theory starts falling apart. But let's just say he does pull it off, and sells all three at $100 each. He's then covered costs and made about $150 on top of it, which would cover the costs of... On top of that, he'd have to buy each toy, and for him to do such a good job casting them, I'm sure he would have to own at least an oil pump ($350 for a decent one) and some type of bell jar or vaccuum chamber which would run around $100 at least. Well, you could build a pressure chamber for $25 (not counting the cost of the compressor)... http://216.239.53.104/search?q=cache:egDfi5FheZ8J:chrismarsh-land.itgo.com/Pressurechamber2.html<>p Of course, he may not have the pump and chamber, and might just be painting the cast or epoxy on the surface to show have a clean surface, and then doing another pour to fill the inside and tap the mold continuosly, but that would take experience and I don't think it would come from Joe blow with zero feedback. I agree. I don't think it's painted. I think it's really plastic of some sort. For me to be right, this guy would have to be a resin casting master on a tight budget. I think it can be done using low cost materials, but maybe I overestimate joe blow's technical expertise. Now let's say the person operates the machine and in charge of it's QC can decide what color plastic goes into the hooper, well he can say, let's just use a standard white this time... Yup. I'm leaning more toward your theory now. On a semi unrelated note, at OTFCC Glen said Takara knows where the production leaks are but they can't do anything about it. He said it's really easy for the culprits to do it, too.
esteban with evil rubber MOLDY UNIT |
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Date: Fri, 01 Aug 2003 18:30:22 -0000 From: "Bond. Estebond" Subject: Re: My What the Crap Auction! (I want this thing!) ---Mark: if a Tracks is already made for an aging study and they were done with the study, tracks could walk away MUCH EASIER imho. ---Himawari: When the machine starts up, or when a mold is removed and a new one placed in, of course they will do color test, and shrinkage tests etc, the workers have simply Hmm... I'm kind of interested in how many test pieces Takara does on a given mold. Between possible shrinkage tests, aging studies, and color tests, there's at least three versions right there that may be produced at the factory before actual production starts. steve-steve moldy
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Date: Fri, 01 Aug 2003 18:30:22 -0000 From: "Bond. Estebond" Subject: Re: My What the Crap Auction! (I want this thing!) ---Mark: if a Tracks is already made for an aging study and they were done with the study, tracks could walk away MUCH EASIER imho. ---Himawari: When the machine starts up, or when a mold is removed and a new one placed in, of course they will do color test, and shrinkage tests etc, the workers have simply ---Steve: Hmm... I'm kind of interested in how many test pieces Takara does on a given mold. Between possible shrinkage tests, aging studies, and color tests, there's at least three versions right there that may be produced at the factory before actual production starts. Not necessarily, they may do all their testing on one peice. however, they may have to run it for a while until the color is completely uniform. If their cycle time isn't calibrated well, then they will have more shrinkage if the cycle time is to fast. The quicker the cycle time, the more the shrinkage. As for the plastic, the pigment is used with colored pellets that have been measured to a ratio, but may take a few runs before it is a consistant color. For example if I measure a ratio to make red, lets say at a ratio of 3red to one white, the first few shots may be pink to a light red before it becomes the consistant red color. Hence the term "test shot". A stress test or shrinkage test could be performed on any of these lighter colored ones since it's only a matter of pigment, the cycle shot is still the same, resulting in the same shrinkage if the cycle time is not adjusted. Of course shrinkage sill determine on how the mold was designed and if the cavity is close to the sprue or not. Sometimes shrinking maybe only in one direction and not uniform. But that would be the result of a poorly designed mold. And if in design it couldn't be helped, shrinkage % would be taken into consideration in the creation or design of the mold, and would be made bigger in the direction of the shrinkage. Anyhow, my point is, these things are most surely made of test shot pieces put together frankenstein style. I'm sure most of these machines run 24/7 so it doesn't have to be during a persons lunch break, and it is more than one machine in operation, a large company will have at least a small handfull, to many depending on the size of the company and how many people on the floor. But, I still like the term "lunchtime special" it7s so cute. Thanks. -Himawari
"An unbreakable toy is useful for breaking other toys." |
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