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A question about "corrected" parts


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I have a question for people that make the so called "corrected" parts for kit a manufactures that has produced a kit with the so called "wrong part". Where are you getting your information from that they seem un-able to find? I can't see you going out to every airplane in the world and taking detailed measurements. That would be to expensive. That leaves documentation from books, manuals, etc that most of use can find. What makes your part correct and theirs wrong? I'm not talking about highly detailed seats or the inside of a panel. I get that. You can do more detail in resin than you can in plastic. I'm talking about a nose shape or tail stinger or a correct fairing. Why do they get it wrong and you get it right?

Steve

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There's research, and then there's research. A perfect example is the much-maligned HK B-17G with its "fatal error" in the shape of the fuselage just ahead of the windscreen. HK originally used the "really nice" drawings by Shigeru Nohara found in the Aero Detail book. The drawings are very nicely done, look very pretty, and "appear" to be accurate. Unfortunately there's not a single part of them that's accurate when compared to a real B-17. Had HK had access to the kind of data that was made available to them after the fact, they'd undoubtedly have gotten that shape right. Several folks with some knowledge of the B-17 worked with HK to help them correct some of the major errors found in their original CAD design, mostly based on collective knowledge of the real airplane that the kit designer didn't have. HK learned a lesson from that, and has been going out of their way to reach out to knowledgeable folks and folks with good connections to get better data for future projects.

Going back to original source documents is always the best bet, but not always possible. Sometimes the stuff simply doesn't exist, or it may just be hidden so well that it's impossible to find within the timeframe required. Given unlimited time and an unlimited budget for research, any kit manufacturer could put out perfect kits every time. If every kit manufacturer had a firm policy of trying to put out the absolute best, most accurate kits they could possibly do, they could probably come pretty close. Accurate Miniatures was an example of that. Were their kits all perfect? No, not remotely. They're human, and they were working with finite resources. But they came pretty darn close. Tamiya has much the same policy with their 1/32 masterpieces. They spend a huge amount of time and money doing good, firm, basic research. Their designers become intimately familiar with the real aircraft (or tank or whatever) before they ever sit down to start their design. Other companies don't do that. The CAD designers at many companies are obviously extremely talented CAD designers, but it's just as clear both that they know *nothing* about real aircraft (or a bare minimum at best), and that they have not taken much more than the path of least resistance in their "research" on their projects. That's why you get things like the (IMHO) garbage that's being put out by several Chinese and other companies. Their goal is to get the kit out the door as soon as possible, with little or no regard to how accurate it is.

And as an aside, as long as modelers keep encouraging this by spending money on these mediocre kits because "...it looks like an XYZ to me", when they themselves don't know much of anything about the real aircraft, nothing will change. Only by voting with your wallet can this kind of situation be changed.

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Something for you to consider. Not every person that is behind an aftermarket line (the owner, sole proprietor, etc.) has first hand knowledge of every aircraft they produce detail sets or decals for. Many rely on the collective expertise of lots of friends in the hobby to provide reference material, and in some cases masters, to produce the corrections they release. Like Jennings stated above, there is research and there is research.

MRC released a 1/35th AH-1W several years ago. I am pretty confident they did 'research' before releasing the kit.

Over the course of 7 years, I completely measured the AH-1W (several aircraft over that time period with a tape measure and plumb lines) and bounced them against station drawings I received from Bell. I have approximately 1800 photos of the AH-1W as well.

I can tell you with 100% certainty that the MRC kit is completely out of proportion and inaccurate in almost every conceivable detail.

Most model kit manufacturers are in this for the profit and don't have subject matter experts on hand for the kits they produce. Most aftermarket companies are owned and operated by current and former subject matter experts and are in this for the love of the hobby and the appreciation of the aircraft kitted.

That in a nutshell is why they get it 'wrong' and we make it 'right'.

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I'm surprised laser scanners aren't used to get the gross shapes and dimensions of subjects down.

Even if they were, it still would not always look right.

"Scale" is an art all in its own. When we look at a 1:1 scale aircraft our eye sees perspective and light differently than in say 1:48 scale. Alerntatively, consier our eyes are 48:1 scale looking at a miniature. There is a fishbowl affect in our vision and light reflects differently.

That said, some manufactures simply get the baisics wrong due to poor research.

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I'm surprised laser scanners aren't used to get the gross shapes and dimensions of subjects down.

Give it time. I'm sure those type of measuring techniques will be employed more often once the cost of the tech comes down. That being said, I don't think that a current military aircraft will be open to such research. I can't see the USAF allowing someone to pull out laser scanners on a front line fighter.

As other's have said, it's mostly about time and money. A company producing an injection molded kit already has a big expense in just producing the kit. Those companies that care about accuracy (Tamiya, Wingnut Wings etc...) will take the time and invest in good solid research because they feel it is worth it to stand apart when it comes to accuracy. Other's don't feel the cost (and time) of research is worth it so you get missed shapes and glaring errors.

But for an aftermarket company, there is not NEARLY as much cost in production. And research isn't really a huge added cost holding up production. They can take the time to really comb over material and get it right. Making molds for resin or vacuum forming also is peanuts compared to machining steel molds so they can try and try again until the product is right. That's not the case with an injection molded kit.

And like Jennings said, a good cad designer does not mean a good model. Fast is good and unfortunately accuracy is a time killer.

That's my take on it anyway.

Bill

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I'm surprised laser scanners aren't used to get the gross shapes and dimensions of subjects down.

Have you priced what it costs to get something the size of an aircraft laser scanned and the data imported into a CAD program? It ain't cheap....

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I've never been a big fan of scale effect and perspective on kits and colors (though I appreciate it on the Parthenon), my desire is for an accurate scale model. Seriously, how much a piece for something man-portable that will be "good enough" for 1/144-1/32 (pull some examples, let's compare prices and capability)? I figure, eight post-mounted laser scanners (four low, four high), find a museum that will let you set-up and scan their displays.

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This is a philosophical question: What is accurate?

If I walked away from a parked aircraft until it was approx the size of a 1/48 kit, you would NOT notice many details. However if a kit manufacturer made it that way, we as a modeling community would go rivet-counter mad. So a model than, is an illusion of what we think is there when we are closer to the real thing? Is this art or science?

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Why do they get it wrong and you get it right?

Hi Steve

There's another issue that is an important one that doesn't seem to have been discussed.

Molds for injection kit parts are expensive in setup and are subject to a number of technical limitations.

One it the 'undercut' which means the shape of many items are limited. A good example of this is clear 'bubble-like' aircraft canopies. For a number of years aircraft canopies for some manufacturers were consistently wrong because they only used a 2-part mould meaning the actual real-world shape of the canopy was impossible to achieve. So a compromise must be created to deal with the fact that the part needs to be released from the mould - no undercuts. It had nothing to do with the actual reference material available. Bad registration on mould halves meant that a three-part mould, required to reproduce the shape exactly, was not able to be done. More recently, however, three-part moulds for canopies it now much more prevalent due to investment in machining and development in technology. So more accurate injection moulded canopies are available. HOWEVER, they still do not get the 'thickness' correct, whereas a vac-form version can deliver a much clearer and closer to scale version. Whether the shape is exactly correct is up for debate.

For resin after-market part creators they can often get much better detail on their parts than injection kits simply due to the fact that undercuts can be done with RTV rubber and resin, and sharper detail is available.

For photo-etch aftermarket parts, they can create detail that is simply impossible with injection kits or resin-cast parts.

So really, in some cases, the big boys like Trumpeter, Hasegawa, Revell, etc, don't get things wrong intentionally - in some cases it's simply because of technical limitations of their manufacturing process.

Edited by PetarB
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This is a philosophical question: What is accurate?

If I walked away from a parked aircraft until it was approx the size of a 1/48 kit, you would NOT notice many details. However if a kit manufacturer made it that way, we as a modeling community would go rivet-counter mad. So a model than, is an illusion of what we think is there when we are closer to the real thing? Is this art or science?

That is not totally correct. When you get to a distance away from a real aircraft to make it appear the size of a scale model, you have to consider atmospheric interference (haze, heat waves, dust etc...) That is part of the reason your eyes can't see as much detail. When you look at a model up close, or even at a few feet away, there is none of that there so you could in fact see details that were 100% accurate to scale (rivets, panels etc...) I do somewhat buy into the "scale effect" argument when it comes to colors (because of that atmospheric interference colors also change) but not shapes or details.

Also, the aspect ratio and focus point isn't comparable at all. For instance, try this. Go stand next to a real jet about 2' away from the fuselage. You can see a lot of detail very clearly because 2' is a good focal length for your eyes. Now get a 1/48 scale model of the same subject and put it 1/2" away from your eye (a scale 2') What can you see? Probably nothing but a blur because the focus point is too close. That is the reason scale effect isn't a good measurement on models.

Accuracy IS a measurable entity.

Just my 2 cents.

Bill

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That is not totally correct. When you get to a distance away from a real aircraft to make it appear the size of a scale model, you have to consider atmospheric interference (haze, heat waves, dust etc...) That is part of the reason your eyes can't see as much detail. When you look at a model up close, or even at a few feet away, there is none of that there so you could in fact see details that were 100% accurate to scale (rivets, panels etc...) I do somewhat buy into the "scale effect" argument when it comes to colors (because of that atmospheric interference colors also change) but not shapes or details.

Also, the aspect ratio and focus point isn't comparable at all. For instance, try this. Go stand next to a real jet about 2' away from the fuselage. You can see a lot of detail very clearly because 2' is a good focal length for your eyes. Now get a 1/48 scale model of the same subject and put it 1/2" away from your eye (a scale 2') What can you see? Probably nothing but a blur because the focus point is too close. That is the reason scale effect isn't a good measurement on models.

Accuracy IS a measurable entity.

Just my 2 cents.

Bill

Great stuff, that's the kind of detail I wanted to facilitate. :cheers:

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Hi Steve

There's another issue that is an important one that doesn't seem to have been discussed.

Molds for injection kit parts are expensive in setup and are subject to a number of technical limitations.

Bingo. Furthermore they are often trying to make profit. Accuracty may be down on their list of priorities.

Whereas someone in the aftermarket may be motivated to improvment by sheear joy of the art. Profit may not be a motive, they may just want to cover their costs + a little extra for beer money. :cheers:

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More recently, however, three-part moulds for canopies it now much more prevalent due to investment in machining and development in technology. So more accurate injection moulded canopies are available. HOWEVER, they still do not get the 'thickness' correct

The thickness isn't correct because there's a minimum size cavity required by clear plastic to flow properly. Anything smaller and the clear plastic won't flow properly and you get misformed parts. This is why the canopy thickness for a 1:32 scale aircraft is the same as for a 1:72 scale one. The disadvantage of the 3 part mold system is that horrible seam down the centre line of the canopy that needs to be removed. Your typical modeller isn't going to want to (or have the skill to) deal with that. I personally hate polishing those things off. Terrified I'm going to crack the plastic. There are times I'd rather have the slightly out of profile canopy (that you would probably never notice) than have that seam to deal with.

Yes, you can get a much thinner canopy with vacuum form but then, an injection molded one, although thicker, isn't going to turn yellow after six months either.

Other things like landing gear legs have to be scaled up slightly in some cases to support the weight of the model. So the struts are sometimes a bit thicker than they should be. Although, I can't say I've ever build a model with the correct depth dimension of a landing gear bay.

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There's research, and then there's research. A perfect example is the much-maligned HK B-17G with its "fatal error" in the shape of the fuselage just ahead of the windscreen. HK originally used the "really nice" drawings by Shigeru Nohara found in the Aero Detail book. The drawings are very nicely done, look very pretty, and "appear" to be accurate. Unfortunately there's not a single part of them that's accurate when compared to a real B-17. Had HK had access to the kind of data that was made available to them after the fact, they'd undoubtedly have gotten that shape right. Several folks with some knowledge of the B-17 worked with HK to help them correct some of the major errors found in their original CAD design, mostly based on collective knowledge of the real airplane that the kit designer didn't have. HK learned a lesson from that, and has been going out of their way to reach out to knowledgeable folks and folks with good connections to get better data for future projects.

Going back to original source documents is always the best bet, but not always possible. Sometimes the stuff simply doesn't exist, or it may just be hidden so well that it's impossible to find within the timeframe required. Given unlimited time and an unlimited budget for research, any kit manufacturer could put out perfect kits every time. If every kit manufacturer had a firm policy of trying to put out the absolute best, most accurate kits they could possibly do, they could probably come pretty close. Accurate Miniatures was an example of that. Were their kits all perfect? No, not remotely. They're human, and they were working with finite resources. But they came pretty darn close. Tamiya has much the same policy with their 1/32 masterpieces. They spend a huge amount of time and money doing good, firm, basic research. Their designers become intimately familiar with the real aircraft (or tank or whatever) before they ever sit down to start their design. Other companies don't do that. The CAD designers at many companies are obviously extremely talented CAD designers, but it's just as clear both that they know *nothing* about real aircraft (or a bare minimum at best), and that they have not taken much more than the path of least resistance in their "research" on their projects. That's why you get things like the (IMHO) garbage that's being put out by several Chinese and other companies. Their goal is to get the kit out the door as soon as possible, with little or no regard to how accurate it is.

And as an aside, as long as modelers keep encouraging this by spending money on these mediocre kits because "...it looks like an XYZ to me", when they themselves don't know much of anything about the real aircraft, nothing will change. Only by voting with your wallet can this kind of situation be changed.

Jennings makes several valid points here. Of course, the downside to the 'total research' approach is cost - that's why the Tamiya 1/32 Spitfires are much more accurate than the Trumpeter versions, but they're also three-and-a-half times more expensive (£140 from Hannants, compared to £40 for the Trumpeter versions). That's a lot of extra cash for all that accuracy. It would be interesting to see both Tamiya and Trumpeter produce, say, a 1/32 Hurricane for £40 and then compare the two.

Vince

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That is not totally correct. When you get to a distance away from a real aircraft to make it appear the size of a scale model, you have to consider atmospheric interference (haze, heat waves, dust etc...) That is part of the reason your eyes can't see as much detail. When you look at a model up close, or even at a few feet away, there is none of that there so you could in fact see details that were 100% accurate to scale (rivets, panels etc...) I do somewhat buy into the "scale effect" argument when it comes to colors (because of that atmospheric interference colors also change) but not shapes or details.

Also, the aspect ratio and focus point isn't comparable at all. For instance, try this. Go stand next to a real jet about 2' away from the fuselage. You can see a lot of detail very clearly because 2' is a good focal length for your eyes. Now get a 1/48 scale model of the same subject and put it 1/2" away from your eye (a scale 2') What can you see? Probably nothing but a blur because the focus point is too close. That is the reason scale effect isn't a good measurement on models.

Accuracy IS a measurable entity.

Just my 2 cents.

Bill

Visiting a control tower when I was young I still remember looking down on all the Euro I painted C-141s, UH-1Ns, -53s, and C-130s and from that height and distance I was amazed how they all "looked like models" I think the "viewing angle" helped too. Example:

Manchester%2BAirport%2B20%2BMillion%2BAir%2BTraffic%2BPOkKJlrH7SOl.jpg

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I believe somebody brought it up before, but sometimes even the best companies with the most resources like to massage the shapes once in awhile. Take Mattel in their Hot Wheels line of diecasts. Many years ago I saw them pantagraph down the shape of a C5 Corvette and use the data to carve a master (3x size relative to the final diecast I believe) in realtime with their equipment. Pantagraphing is nothing new as it has been done for years by the model car industry as well (albeit the equipment has improved).

You would think they have the "perfect" shape since they pantagraphed down the full size vehicle right? Not necessarily as they looked at the shape closely. The fenders didn't look quite right as those trademark Corvette haunches and curves didn't read quite as well in a smaller scale. So they manipulated the shapes a little to give it the right "look" even if it might not be dead on perfect.

Scale models are the "illusion" of a full sized object. The shape and parts from the manufacturer are just the starting point. It is still up to the skill of the individual modeler to put it all together into a cohesive whole, then paint, decal and weather the thing before ending up with something that looks like real life, only smaller.

There have been times where I've tried to achieve some sort of "technical perfection" on a model by building it the best I could, correcting every tiny little flaw and the like. But I've got to tell you, it can be fatiguing as hell. In the end, if I were to build two models side by side and do that with one having ALL the "accurized" resin bits and the other being built more out of the box, putting identical efforts into the paintjob, weathering and decals, one might be hard pressed to determine which was done better on a contest table. There, some of those "obvious shape errors" might not be as noticeable, especially to somebody who hasn't built said model. Others would just look at them and say "those are some dang fine looking models." These days, I am more about building the "forest" rather than a whole bunch of trees. So some areas I might overlook while focusing on other more important ones. In the end, I believe it has made me a better modeler.

As to why "accurized parts" are available, it is because there is a market for it. A market means there is a demand and people will buy them. Some parts I don't give much thought to at all, such as the infamous "pre-bulged" tire craze that started up about 20 years ago (how much money was made on those things?). Other pieces, like say a PBY engine cowl or exhaust stubs for a WW2 Spitfire I might go for, because they do help save time and provide a nice alternative to a potentially costly shape fix. Gear bays, access ports in fuselages probably not so much in my case. Aftermarket cockpits I sometimes use, although I have noticed that there are many kit cockpits that can be made to look just about as good with a little bodge work and creative painting. Generally though, if it is hidden unless I crane my neck to look underneath something, I typically don't worry much about it.

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I normally don't get upset about a kit being a millimeter "off" here and there (and I work in 1/72) unless it really throws off the "look" of an aircraft. Sometimes there are shape errors that I never notice, but once pointed out stick out like a sore thumb to me. I've heard "boffins" and "experten" routinely trash the Tamiya and Hasegawa Spitfires and 109s, but I gotta say their 1/72 kits look just fine to me.

Off course, we all have our "sacred cows"..in my case, it's the B-24 Liberator. I remember how thrilled I was when Academy/Minicraft released a series of new-tool B-24s in the early 90s..up until then the only options in 1/72 were the rather crude and toy-like Revell and Airfix kits. Unfortunately, I was immediately turned off by the Academy kits' noticeably undersized and poorly shaped engine cowls..a primary reason why I've never finished one, despite having a dozen or so in The Stash. Since the aftermarket was just barely getting started back then, I endeavored to create my own replacement cowls, by re-shaping and scribing an old Airfix cowl and casting copies. I was fairly successful, but still never managed to finish the project (I always got bogged down trying to add interior detail.)

One thing that baffles me about some of the aftermarket companies is the choice of subjects. Quickboost makes some great stuff, but a lot of their products and simply copies of the original kit parts with a little extra detail added..while ignoring more glaring inaccuracies in the same kit. I can only assume the parts sell, and like the kit manufacturers they have to consider the cost of making an entirely new and more accurate part vs. the profit they would make. The aforementioned Minicraft B-24 is a great example. QB has released engines, props, superchargers, bomb bay doors, and I think a few other bits to improve the kit, but has completely ignored the cowls, its most egregious issue. Of course, in order to fully correct the kit you would need to sculpt entirely new nacelles forward of the leading edge, a fairly major undertaking for an aftermarket company. The new Hasegawa B-24s got it right, but are not as widely available as the Minicraft kits, and much more expensive. It seems to me there would be a ready market for Minicraft replacement nacelles, but I can only assume the various aftermarket firms have done the math and determined the potential profit wouldn't justify the cost. When I've brought up the issue with those who've built the Minicraft kits, most had never even noticed it (like I wouldn't notice slight shape errors on a Spit or 109.)

SN

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