F-16CJ canopy problem - Tamiya official response

[Vodnik]

Thanks to Rainow Ten online shop I received information about official Tamiya Japan response to the canopy scratch problem:

"1: the thickness of the clear part is the least thick for the plastic material and can not be any more thin. In the process of molding the clear part, the plastic material does not go throuhg the mold thoroughly (but enough to make a form) and because of that, this scar will be produced. This is not actually a scar or scratch but the trace of plastic material flowing into the mold when in the liquid form. Imagine two currencies of water go meet in the middle of the river and make a line in the middle, and then those go frozen immediately to ice, then you will see the line in the middle.

2: They actually tried to overcome this flaw in the development stage, by making a protruding point at the both end of the parts so that more plasitc go flow into, but this innovation did not work well enough to solve the problem.

3: The only way to solve this problem is use compound to wipe it out.

4: In conclusion, TAMIYA acknowledged this is not a production faulty."

Pawel

[David Walker]

4: In conclusion, TAMIYA acknowledged this is not a production faulty."

I'm not quite sure I'd agree with that one.

[Gary West]

ok so it's not a production issue, so it's a design flaw instead - what's the difference?

[Aggressor Supporter]

Guess it time to start buffing.....

Edited April 30, 2007 by Raptor Supporter

[doctorpepper]

Also, F-16 canopies are not the most spotless things on earth.

hell yeah!

[smithery]

Thanks to Rainow Ten online shop I received information about official Tamiya Japan response to the canopy scratch problem:

"1: the thickness of the clear part is the least thick for the plastic material and can not be any more thin. In the process of molding the clear part, the plastic material does not go throuhg the mold thoroughly (but enough to make a form) and because of that, this scar will be produced. This is not actually a scar or scratch but the trace of plastic material flowing into the mold when in the liquid form. Imagine two currencies of water go meet in the middle of the river and make a line in the middle, and then those go frozen immediately to ice, then you will see the line in the middle.

4: In conclusion, TAMIYA acknowledged this is not a production faulty."

Based on my experience of running a plastic factory, this is totally bogus response. They got it right on the 1/32 kit, and other kit manufacturers don't seem to have too much problem making a 1/48 canopy for the Viper.

And yes, it is a production fault. If the part isn't perfect, you make corrections until it is. Period.

[lgl007]

Could this be a 'translation' issue? I find it hard to believe that Tamiya, world renowned for their models and constant drive for perfection, would issue such an ASININE explanation. How can this NOT be a production fault. I do not believe any of their other kits have this issue? Nor do their competitors... therefore Tamiya... the ALMIGHTY Tamiya... f'd up!

I guess the good news is that it will buff out... gotta buff out the damn seam in the middle anyhow ;-)

L8ter gents...

-Greg

[Bails]

It took me about 20 minutes to clean-up and polish-out the canopy/windscreen pieces.....final buffing with my favorite "buffer".....small piece of an old all cotton flannel shirt. No Future required.

Bails-In-Minnesota

Edited April 30, 2007 by Bails

[longmc]

Also, F-16 canopies are not the most spotless things on earth.

EXACTLY!! Especially when being sandblasted in the desert!!

[JimC]

I'm going with translation error. I really think they are talking about the molding seam there the more I read it, as they seem to be saying that there is no way to avoid it, which there isn't. Also, the "flaw" isn't present in every canopy. I've now buffed out 2 of them to unrealistic perfection.

Scott,

I have to agree with you here. Notice the bold text from Tamiya. I think that clears it up

Imagine two currencies of water go meet in the middle of the river and make a line

in the middle, and then those go frozen immediately to ice, then you will see the line in the middle.

While I haven't got to my canopy yet (I just got my new airbrush, so I'm trying to figure out

how to avoid spatter...I'm getting build-up on the tip of my new Inifinity).

Jim

[MickeyThickey]

It is absolutely not a translation error - they are talking about the 'scar', 'flaw', whatever. In fact, I can't really see how you could mis-interpret it as anything but. It's the result of the plastic's flow. The problem occurs because two 'waves' of plastic are flowing together inside the mold cavity, and that results in a very faint 'seam' where they meet; they tried to fix it by making the plastic flow into a deeper cavity, but this didn't work. The canopy seam is the product of a three-part mold - there's a seam in the part because there's a seam in the tooling. Adding extra bits to the sprue isn't going to change this. And the seam line has nothing to do with how thoroughly the plastic flows through the mold. If you don't think their explanation makes sense as-is, it makes even less sense if it refers to the seam line.

If it's any help, does this clarify their explanation?

Imagine two currencies of water go meet slightly to the left of the river and make a line slightly to the left, and then those go frozen immediately to ice, then you will see the line slightly to the left.

I would have thought that the solution would be to have the plastic flow through the tooling differently - play around with the shape of the sprues and the location of the attachment points - rather than adding a few knock-out pins. Or playing with the pressure. And I'm kinda surprised they couldn't fix it, though I find myself wondering, what did it look like in the test shots, since I'd assume their tweaks at the very least helped. As I'm guessing there's a fair whack of computer modelling that goes into tooling design, shouldn't this kind of thing be flagged before the steel gets cut, or is it just because of the super-tight tolerances with clear plastic?

Edited April 30, 2007 by MickeyFickey

[FrankC]

I don't understand the response at all ..

I think they might be talking about the molding seam? But OTOH maybe they are talking about the mold crack we have been discussing?

But either way it looks like there will be no relief from Tamiya. I guess you buff and whatever you get is what you get. I buffed mine out but I can still see the crack if the canopy is well lit (such as illuminated with a judges flashlight - lol).

It's still a great kit - I am not overly disappointed. If anything it just goes to show you that any manufacture can have problems even the might TAMIYA!! However, I don't understand how HASEGAWA can make a F-16 canopy that DOESNT have this flaw though. If the explantion is saying it's not possible to do this, then Hasegawa must have some soft of magical gnome who takes care of such impossiblities for them..

[Two Mikes]

my issue is that tamiya seem hell bent on not replacing the canopies. I am sorry but for an industry leader who prides themselves on perfection and standards they are leaving me high and dry on this. I am still holding on hopethat it is a translation error. I would guess that they have seen at least one photo of the "flaw" by now.

[Two Mikes]

It took them a while to fix the glass on the P-51s, but they did. I still don't think they meant that the way it came out....something is lost in there someplace. In theory there shouldn't be any difference in molding an F-16 canopy in 1/48 or 1/32.

Refresh my memory Scott....was the glass on the P-51 the part that you couldnt cut off the tree without damaging the actual "glass"??

[JimC]

Guys,

FYI-

I just called Tamiya Customer Service (800) 826-4922 (US only) and spoke with

a Customer Service rep there about the seam/crack/line in the 1/48 F-16CJ canopy.

He said that they opened three (3) kits there but didn't see anything, AND YET...

He also told me that he only had one other call related to the canopy, but said

that his boss had ordered a bunch of canopies from Tamiya that would be there

(Tamiya America) in "two to three months".

If you live in the US and it's an issue for you, call Tamiya Customer Service and

let them know. They don't seem to think it's a widespread problem.

Jim

[Two Mikes]

Yeah, they moved the sprue attachment point to where the bottom mating surface on the side panel was on top of the sprue so it could be cut off without marring the actual side panel....all the attachment point was on the mating surface instead of the side glass panel.

Took 'em a while, but they did it after numerous customer complaints...same with the meteor speedbrakes and 109 nose.

I don't think this issue has nearly that sort of impact, but if it bugs enough people, then they might see about fixing it.

2 of mine from HLJ had them, the one I got at the LHS didn't. Different production batches?

The four kits I got from Squadron were all problem free. Maybe it was an early batch problem?? I got my kits a few weeks after people here were bragging about their HLJ orders

[gtypecanare]

Guys,

FYI-

I just called Tamiya Customer Service (800) 826-4922 (US only) and spoke with

a Customer Service rep there about the seam/crack/line in the 1/48 F-16CJ canopy.

He said that they opened three (3) kits there but didn't see anything, AND YET...

He also told me that he only had one other call related to the canopy, but said

that his boss had ordered a bunch of canopies from Tamiya that would be there

(Tamiya America) in "two to three months".

If you live in the US and it's an issue for you, call Tamiya Customer Service and

let them know. They don't seem to think it's a widespread problem.

Jim

Yup,

I was at Tamiya America this afternoon and showed the Customer Service Manager the "problem".

Edited April 25, 2008 by gtypecanare

[Falkirk1298]

I take it we're talking about a transparent version of the flow marks and whirls you used to find, particularly in silver plastic?

John

[JimC]

I take it we're talking about a transparent version of the flow marks and whirls you used to find, particularly in silver plastic?

John

John,

Check this out:

http://www.arcforums.com/forums/air/index....howtopic=118813

Go to Page 2 and scroll down for pics...Post #27 has a good pic of the issue.

Jim

Edited May 1, 2007 by JimC

[Falkirk1298]

Thanks Jim.

It is rather strange, isn't it?

John

[Zactoman]

I'm no injection molding expert, but that appears to be a 'cold flow' (also called 'weld line' or 'knit line') problem .

As I understand it, it can be caused by several controllable factors including temperature of the plastic being injected, temperature of the mold, pressure at which the plastic is injected and the type of plastic being injected.

Clear styrene tends to cool faster than opaque. As the plastic flows into the mold it fills from different directions determined by the sprue configuration, cavity size and shape, vents and gates.

If the plastic cools before it meets it forms cold flow lines...

Depending on how cold the plastic was, the lines might just be on the surface or they may run all the way through the plastic. If they do go all the way through, they can't be sanded and buffed out or hidden by Future.

It is a molding problem that CAN be fixed by the molder and is obvious in that many of you have parts that show no sign of problems.

In conclusion, it is a production faulty...

[FlyAndFight]

After reading this thread, I checked the canopy on my kit and it appears fine. But knowing that Tamiya USA has a batch of replacement canopies in the pipeline tells me that they are taking this matter seriously and will do right, in the end.

[jiawei_91]

I've got the problem too...pretty disappointed. But how am i gonna get a replacement here? They won't send it to Malaysia, right?

ARRGGHH...

Lim

(and i haven't got any future nor any canopy polishing kits!)

[David Walker]

That's a little easier to get to though than the smaller flaw on the inside of the canopy. Ultimately I expect I'll just take care of the mold seam and the flaw on the outside and call it good. To be honest it took me a while to find it even when I knew where to look. And the other models in my cabinet aren't going to complain about it. :)