A curse on the 1/48th Mirage IIIE and its derivative about to end?

[michelaustralia]

Hi everybody,

It seems that some shape issues on the 48th Mirage IIIE and derivative models were present on the older releases and are still existing on the new ones, like for instance on the two beautiful Kfir models on the market from AMK and Kinetic.

Maybe it is due to the use of some drawings available online considered to be accurate and showing this mistake? Who knows…

Example:

The problem? The quite undersized air intakes.

The air intake size on the Mirage aircraft varies depending of the Engine used. Roughly, the more powerful, the more air is needed.

The Mirage IIIC having the Atar 9B engine has the smallest air intakes, then on the IIIE and derivatives using the Atar 9C, the air intakes had to be bigger, same when the again more powerful 9K50 engine was used, and again when the J79 engine was used on the Kfir.

By extending a line from the edge of the wing to the front fuselage on the drawing, we can see that on this line goes under the air intake. Doing the same on a picture, this line cut through the intake.

It is much more obvious when we look at the front of the subject:

Another comparison with the real subject and a more correct Cad file:

So we have some asthmatic aircrafts here and it changes the whole appearance of the model.

An interesting picture of an Eduard Mirage IIIC and an AMK Kfir, brilliantly made by Hellcat, from the French Forum Fighters.forumactif.com.

The IIIC air intakes looks pretty right, but the Kfir intakes are way undersized; they should be bigger than the IIIC.

To correct such shape on an existing model is a massive job and hopefully the next Mirage III release(s) expected soon will have the correct intake size.

[Laurent]

Great post Michel ! You've made a point here

The drawings are from a Koku Fan ? And the CAD front view is the one of the incoming HPM model (frankenstein model: Finger nose with Doppler bulge) ? Do you know if we can expect the HPM kit under the Christmas tree ?

[michelaustralia]

Hi Laurent,

Thanks. I don't know where the drawings are from, just took it form the Web and quite interestingly, a lot of them show this mistake.

The CAD is effectively from the HPM, used for the 72nd model and upgraded for the 48th.

I really don't know about the expected release date of the 48th, sorry.

[Laurent]

I don't know where the drawings are from, just took it form the Web...

Well there's Japanese here.

... and quite interestingly, a lot of them show this mistake.

Same with the Aviatsia i Vremiya ones I'd say.

[michelaustralia]

I looked on the book Mirage IIIO colours and markings and the scale plans from Juanita Franzi seems quite correct in this area.

[pookie]

I have the Isradecal book on the Kfir. The intakes on the Kfir are as not as tall as the IIIC so you cannot say that Kfir intakes have to be the same or bigger as those in the IIIC.

Looking at the pictures of the actual aircraft on the book and the line drawings, it seems the AMK kit has the correct shape and size intakes for the Kfir. The cone inside the intake is what seems to be the wrong size and/or shape. The AMK kit has a pointy cone while the actual aircraft has a more blunt cone.

Edited September 30, 2014 by pookie

[Laurent]

The AMK kit has a pointy cone while the actual aircraft has a bore blunt cone.

http://data3.primeportal.net/hangar/bill_spidle4/kfir_c2_n406ax/images/kfir_c2_n406ax_07_of_51.jpg ?

[Laurent]

Looking at the pictures of the actual aircraft on the book and the line drawings, it seems the AMK kit has the correct shape and size intakes for the Kfir.

If I admit that the profile in this page is based on the CAD and that I compare it to a photo like this one, the intake looks smallish to me.

Edited September 30, 2014 by Laurent

[michelaustralia]

I have the Isradecal book on the Kfir. The intakes on the Kfir are as not as tall as the IIIC so you cannot say that Kfir intakes have to be the same or bigger as those in the IIIC.

Looking at the pictures of the actual aircraft on the book and the line drawings, it seems the AMK kit has the correct shape and size intakes for the Kfir. The cone inside the intake is what seems to be the wrong size and/or shape. The AMK kit has a pointy cone while the actual aircraft has a more blunt cone.

Hi Pookie,

My comment is based on what I have read and heard about the size of the air intakes.

As explained on my first post, and this was told to me from a former Dassault Aviation employee, the air intakes area depends of the engine used: More powerful engine=more air needed. That is why the air intakes on the aircrafts using the Atar 9C engine had a bigger air intake area as the engine has more guts than the Atar 9B, used on IIICs. Again, when the Atar 9K was used, the air intakes area had to be slightly increased, and it happened again when the J79 was adapted on the Kfir.

It is also stipulated in some books, like this one:

The International Directory of Military Aircrafts 1996/97 edition:

Now, it is possible I didn’t understand well what the guy from Dassault explained to me, and it is also possible that the readings are wrong therefore I would be very happy if somebody can correct my mistake, and if mistake there is, I apologies to everybody for making wrong comments

Another comparison between the model and the real subject:

Michel

[Laurent]

Now, it is possible I didn't understand well what the guy from Dassault explained to me, and it is also possible that the readings are wrong therefore I would be very happy if somebody can correct my mistake, and if mistake there is, I apologies to everybody for making wrong comments

Another comparison between the model and the real subject:

I think you're right Michel but the only way to know for sure would be to measure the intake of a real Kfir and scale it to 1/48.

[michelaustralia]

Hi Laurent,

Maybe somebody who has access to a Kfir might help us here...

I measured the height of the intake of our IIIO at the museum, it is about 740mm high (including the aluminium sheet thickness)

So in 48th scale, it correspond to 15.4mm. Considering that the Kfir intake "might" be bigger, let's say that this dimension on the model should be 15.4mm or a bit more, maybe 15.8...

I am talking within the 10th of a millimeter here, which is a bit of an overkill, but I reckon as the difference seems quite important and can be seen visually, and if I am right, the intakes on the AMK/Kinetic might be between 1 and 2 mm under sized.

Michel

[Laurent]

So in 48th scale, it correspond to 15.4mm. Considering that the Kfir intake "might" be bigger, let's say that this dimension on the model should be 15.4mm or a bit more, maybe 15.8...

I am talking within the 10th of a millimeter here, which is a bit of an overkill, but I reckon as the difference seems quite important and can be seen visually, and if I am right, the intakes on the AMK/Kinetic might be between 1 and 2 mm under sized.

I've tried measuring the AMK intake and I've measured 14.5mm (analog caliper) so the intake would be about a mm too small. 6% relative error so it isn't enormous but it isn't negligible either.

[michelaustralia]

I've tried measuring the AMK intake and I've measured 14.5mm (analog caliper) so the intake would be about a mm too small. 6% relative error so it isn't enormous but it isn't negligible either.

Just found 13.8 (digital caliper) on the AMK.

[Laurent]

Just found 13.8 (digital caliper) on the AMK.

Assembled or not ? I'm asking because the insertion of the boundary layer splitter can widden the intake part. Mine is assembled.

Do you have a Kinetic Kfir ?

Edited October 1, 2014 by Laurent

[michelaustralia]

Assembled or not ? I'm asking because the insertion of the boundary layer splitter can widden the intake part. Mine is assembled.

Do you have a Kinetic Kfir ?

Not assembled, and no, don't have the Kinetic.

That's the first time I use a caliper on a model actually. To me, if it looks ok visually, I am happy, and in this case, I find that visually, it seems there is something weird here...

Maybe it is the fuselage which is too high in this area and does give this weird effect? or the wing too low? maybe both?

Edited October 1, 2014 by michelaustralia

[Laurent]

Not assembled

So to me this measurement isn't valid.

That's the first time I use a caliper on a model actually. To me, if it looks ok visually, I am happy, and in this case, I find that visually, it seems there is something weird here...

IMHO that's how rivet-counters, accuracy guys, whatever you call them should do. If something looks weird, then measure to qualify why the thing looks wrong.

Maybe it is the fuselage which is too high in this area and does give this weird effect? or the wing too low? maybe both?

Well if the intake is slightly too small, there's "less mass" at the bottom of the intake and it increases the impression (or fact ?) that the wing is set too low on the fuselage.

Edited October 1, 2014 by Laurent

[michelaustralia]

So it's all good then ;)/>/>

So a 6% error is a "relative" and not an enormous error in this case, but a 1.5% and 2.6% error on some other aircraft is considered unexcusable and almost brought the plastic model word to a melt-down...something I don't really understand here...

Anyway, I found that visually, there is something wrong with these Kfirs. Most people won't care, and as long as they enjoy to built these great models, that's the main thing, our hobby is mostly about having fun !...some other people won't agree on my comments, and it's perfectly fine to me too, and maybe some will agree...

Edited October 1, 2014 by michelaustralia

[Raymond Chung]

So it's all good then ;)/>/>/>

So a 6% error is a "relative" and not an enormous error in this case, but a 1.5% and 2.6% error on some other aircraft is considered unexcusable and almost brought the plastic model word to a melt-down...something I don't really understand here...

Anyway, I found that visually, there is something wrong with these Kfirs. Most people won't care, and as long as they enjoy to built these great models, that's the main thing, our hobby is mostly about having fun !...some other people won't agree on my comments, and it's perfectly fine to me too, and maybe some will agree...

Michael,

I measured our soon to release Mirage IIIE, the length is 15.02 mm (so we are 0.38mm shorter).

[Laurent]

I measured our soon to release Mirage IIIE, the length is 15.02 mm (so we are 0.38mm shorter).

That's 2.5% relative error. Not too bad I guess.

Anyway, as already said, when it comes to shape accuracy, position of the wing root relative to the bottom intake edge in profile view may be more important.

[dragonlance]

Michael,

I measured our soon to release Mirage IIIE, the length is 15.02 mm (so we are 0.38mm shorter).

Damn, Raymond, you just destroyed his sales pitch...

Vedran

[Hoosfoos]

Michael,

I measured our soon to release Mirage IIIE, the length is 15.02 mm (so we are 0.38mm shorter).

Raymond, I for one am very excited and grateful for this release. Thanks for manufacturing it, and you can expect multiple purchases of it from me. Everyone else slagging a release before it has even hit the market can either opt to not buy it or go...(pick an expression of their choice).

Edited October 1, 2014 by Hoosfoos

[michelaustralia]

Michael,

I measured our soon to release Mirage IIIE, the length is 15.02 mm (so we are 0.38mm shorter).

Great news then ;) , thanks Raymond

[nazempar]

Raymond Chung,

Thanks for the information this is very welcome version MIRAGE III in 48 scale until now we had only ESCI carrying the more than 40 years but it is not ideal for

today's standards.

I hope that someone offered to Mirage IIIB. In 1/72 anyway not the normal models only short run and in the Middle Ages.

NzPar