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Mirage IIIO 1/32, Scratchbuild


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8 hours ago, Serkan Sen said:

I have just caught up this build. What you are doing here is amazing. Have you ever considered to machine the woods with CNC?

(maybe I am a bit CAD/CAM oriented.

 


Hi @Serkan Sen,

 

I’m pleased you are enjoying watching the project come together. For me a large part of the appeal of this is the joy of making something by hand rather than through the medium of computing, so I doubt I’ll ever use CNC technology even though it would doubtlessly make a more accurate and precise model.

 

If I was to turn to a computer-based modelling method it would be more likely to be 3D printing. I have had a friend of mine do some 3D printing in the past (the wheels on the Hogwarts Express and the lifeboats on Carpathia) but I try to reserve it only for especially difficult parts or parts that must be reproduced exactly many many times.

 

Thanks for looking in! 👍


Steve

 

 

 

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9 hours ago, Bandsaw Steve said:

For me a large part of the appeal of this is the joy of making something by hand rather than through the medium of computing

I’m with Steve on this one. In my professional capacity I use CAD, 3D printing and CNC machining all the time, I’m sure we’re almost at the stage where on a high end 3D printer you could print a model complete with camo and markings. 
 

For me when making models, half the fun is making it myself. One reason for example why I’ll probably never build a Zoukei Murai or a Wingnutwings kit ( notwithstanding the price) 

 

Which is why I’ve even been known to scratch or convert where there is a kit available, just because I enjoy the task.

Edited by Marklo
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2 hours ago, Marklo said:

I’m with Steve on this one. In my professional capacity I use CAD, 3D printing and CNC machining all the time, I’m sure we’re almost at the stage where on a high end 3D printer you could print a model complete with camo and markings. 
 

For me when making models, half the fun is making it myself. One reason for example why I’ll probably never build a Zoukei Murai or a Wingnutwings kit ( notwithstanding the price) 

 

Which is why I’ve even been known to scratch or convert where there is a kit available, just because I enjoy the task.

Tasks that both you guys Excel in. My jaw drops every time I see an update from you two.

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Rounding things off

 

At the end of the last major post we were up to something like this.  Things definitely looking a bit Miragish, but still all very blocky and squared off. At this point the damned thing could be made of lego!

CB3boT6.jpg

 

I will not insult you all by showing how I glued the two fuselage halves together with the tail stuck in between them. Suffice to say, by the time the photo below was taken the bits you can see are firmly glued together with PVA glue.  Note the laminated cross-sections in the foreground. Immediately after this photo they were cut out with scissors and were very important in the work to follow.

dKaEG5c.jpg

 

Now we start carving away the blocky square edges that don't conform to the desired cross-sectional shapes.

Fh6R1Bi.jpg

 

Not much to it really, just work slowly and alternate which side you work on so that you don't end up all lop-sided.  In this job symmetry is everything. The average viewer probably wont notice a slight inaccuracy in the profile but the human eye picks up asymmetry instantly. Everyone knows that aircraft are symmetrical.

RHDJMzZ.jpg

 

Work slowly and remember that it's always easier to carve more wood off than add wood back, so err on the side of not removing enough.  Work slowly peeling off layers of less than 1mm with each stroke of the chisel. BTW, In this view you can also see I've put some filler in the jet nozzle to ensure a nice smooth interior. It might get a bit of detailing later on.

6lMg5Rk.jpg

 

Keep checking periodically against the templates.

62FRBO6.jpg

 

A contour gauge can also be useful during this process.  At this point I thought I was 'almost there' but you can  see that there's still a lot of carving to go.

XuJTAoE.jpg

 

As we get closer to the final shape we can move to rasps, files and sandpaper. In this regard the process is a bit like woodturning.  The 'fast' tools go first and we move to 'slower' tools as we get closer to the final contour.

wTmqyjm.jpg

 

Nice!

ZBC405C.jpg

 

She's looking OK at this point. I still haven't touched the underside yet; see how the tailpipe is sitting in an arch rather than a circle. Just to give you an idea of how gradually this progressed I reckon that there's about 3 hours carving in this post so far. This is not a hobby for thrill seekers.

fbLrCuo.jpg

 

Flip it over and start again. Rounding off the underside under the tailpipe only took about 30 minutes.

VIT6ucK.jpg

 

Attack the nose in a similar way,  starting with marking up the wood to remove with a series of diagonal lines.

Ve6Z4j1.jpg

 

Topside done - I haven't touched the underside as it risks making the structure under the cockpit floor even thinner and more delicate so I’m going to leave that until as late as possible.

lkUzqhU.jpg

 

And here she goes at this point. Rounded off and looking promising! 👍 

The last three photos are taken on my I-phone, their clarity emphasize just how scruffy the photos from my old shed camera have become.  I'm aiming to get a new disposable point and shoot in the next week or two so bear with me.

LleA2wg.jpg

 

I'm especially happy with the  circularity of the jet-pipe and surrounding fuselage.  I showed Baby Bandsaw and even she with her cynical teenage attitude reckoned it was pretty good. :idea:

3Xf8vFd.jpg

 

On the underside we can still see the boxy contour under the nose as mentioned above and the fact that the underside of the wing is still dead flat.  Just like the rest of the aircraft, the underside needs to be nice and curvey. I'll be dealing with that in the next post.

QcfQVAf.jpg

 

OK Folks that's it for now, thanks very much for all of the interest shown.

 

Best Regards,

Bandsaw Steve.

 

 

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Darn it Steve, just as soon as I start thinking about styrene for ships hulls again you go and create something delightfully curvaceous from wood! I'll never make my mind up this way. 🤔

Oh, BTW, she's looking extremely like a fast jet fighter, in a Miragish sort of way. 👍 Well done and keep it up.

 

I was rather interested in your contour gauge.    Regards, Jeff. 

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19 minutes ago, ArnoldAmbrose said:

Darn it Steve, just as soon as I start thinking about styrene for ships hulls again you go and create something delightfully curvaceous from wood! I'll never make my mind up this way. 

How about wood skinned with styrene?

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That might be an idea, the wood could be more rigid than styrene frames maybe. Might prevent warping. What glue would you suggest for attaching the styrene?

     I've been thinking of a wood hull with a styrene upper deck, and building up with styrene from there. Regards, Jeff.

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4 hours ago, Bandsaw Steve said:

I haven't touched the underside as it risks making the structure under the cockpit floor even thinner and more delicate so I’m going to leave that until as late as possible.

Would it be better to add the cockpit interior such as an ejection seat and the like to help add rigidity ? 

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Great care and patience there Steve. That is really looking the part now. Like all the best series you have left us with a cliffhanger. I can't wait for the next episode to see how you deal with the underside. 

 

Richie

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8 hours ago, Bandsaw Steve said:

Everyone knows that aircraft are symmetrical.

Actually to my surprise I’ve been discovering that particularly with single engine propellor driven planes they aren’t. For example the  engine pod on walrus is actually 10 degrees off true, all of the hawker fury family have an asymmetric tail, the forward fuselage if the mil hind is asymmetric and even the good old me109 had an assymetric rudder, I won’t even mention the Blohm and Voss 144 :) 

 

loving the Mirage, looking amazing already.

 

Black mamba is pretty cool. My favourite forum name I’ve ever seen was in a star wars forum and the name was funkywookiepants, hmm  maybe you had to be there, well it worked for me :) 

Edited by Marklo
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Symmetry. Hmmmm…Yes, there are exceptions. I figured someone might comment on that. You forgot the macchi 202 Folgore with one wing 2 inches longer than the other. All of the sited examples however struggle to reach Mach 2. 😆

 

So let’s rephrase…
 

Everybody knows that the fundamental fuselage shapes (discounting air-to-air refuelling probes, weapons and sensor blisters, vent holes etc) of supersonic jet fighters (almost certainly with some obscure rare exceptions that I have not heard of) are - at least to the casual observer - symmetrical.

😆
 

 

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20 hours ago, Corsairfoxfouruncle said:

Would it be better to add the cockpit interior such as an ejection seat and the like to help add rigidity ? 

Yes it will (especially if I build the interior details onto a brass base) as will the addition of cockpit sidewalls and a brass forward undercarriage bay and gluing the two cockpit halves together . But in the meantime I have to be very careful with the somewhat fragile front-end of this model.

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8 hours ago, ArnoldAmbrose said:

That might be an idea, the wood could be more rigid than styrene frames maybe. Might prevent warping. What glue would you suggest for attaching the styrene?

     I've been thinking of a wood hull with a styrene upper deck, and building up with styrene from there. Regards, Jeff.

I think this method has great merit, especially in 1/600 scale (there might be better methods for larger scales). If you have another look at the first page of my PZH2000 project you will see that I did something very similar with its hull. I used ordinary cyanoacrylate super-glue on some surfaces and Selly’s power-grip for others. The power grip has a longer working time, is very strong and not as brittle as cyanoacrylate. You can get it at Bunnings, it comes in a scarlet tube. If you use power-grip  though you will probably need more clamping than if you use CA glue.

 

Both have worked very well on the PZH2000 so take your pick. 👍

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Anhedral

 

At the end of the last substantive post we had a jet that looked like this...

QcfQVAf.jpg

 

I noted that the underside of the wing was still dead flat and that I had to add a curvey centre-section to the underside.   What I completely overlooked was that the wing needed anhedral. 

 

Questions of anhedral and dihedral used to cause me a lot of angst; have a look at my the Avro 504 project if you want to see just how much.  The good news is that following finally getting the dihedral sorted on the Avro 504 I now have a 'go to' method for both dihedral and anhedral that is really simple and easy.

 

Here it is:

 

Cut the wing front to rear into as many sections as are required to represent the angular changes. For example if I ever built something with gull wings - let's say an F4U Corsair - I would need a  cut at each point where the dihedral / anhedral changes. On the Mirage however things are nice and simple, there is just one anhedral value and it's set at the centerline.  So make a cut on the centreline as shown below...

SpFxYRM.jpg

 

This creates two equal halves.

cnZ0sWP.jpg

 

Now measure the anhedral angle on the top-most surface of the wing. Note that this value -7.7 degrees takes into account not only the true anhedral (measured on the centreline of the wing) but also the wing's taper. which here increases the 'steepness' of the measured angle.

N7hKxvS.jpg

 

Now cut a series of small plywood 'biscuits' with the measured angle of -7.7 degrees cut onto their top surface.

FOvikJO.jpg

 

Cut three slots - one for each biscuit - on each side of the wing. Make each slot slightly too tight to start with and then gradually open them up with sandpaper until the plywood slides in and holds by friction.

RfyHt37.jpg

 

Glue all three biscuits in place on one side.

ZCibeay.jpg

 

Voila...

heQ19s1.jpg

 

Glue the other side into position.  Check the topside anhedral with the original protractor measurement just to make sure it's about right and then let the glue set for a few hours.

oSMYrWX.jpg

 

The lower half of the biscuits can then be removed with a chisel and sandpaper.

xhkMFGG.jpg

 

Use an appropriate filler and sandpaper to return a nice smooth finish to the wing.

RguVQLj.jpg

 

When the job is complete it should look something like thiis.

zvfTJAh.jpg

 

Which when temporarily attached to the fuselage and viewed from the cockpit of my imaginary MIG-21 looks like this.

nc170Tu.jpg

 

and this...

kDDaw8c.jpg

 

So, what was a nightmare on the Avro 504 turned out to be a fairly simple job on the Mirage.

 

Next time I'll get to that curvy bit.... Promise.

 

Bandsaw Steve

 

 

 

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1 minute ago, hendie said:

nice, simple solutions. Always the best.

Yep. 👍

 

There’s also the option of steaming the wood at the inflection point and then just bending it as advocated by the great ‘W.O. Doylend’ in his 1957 book ‘Aircraft in Miniature’. 
 

That’s a good option, but I believe he only worked in 1/72 and used high-quality carving wood for the wings. I’m working in 1/32, so these wings are much ‘chunkier’, furthermore I’m using MDF and I’m pretty sure it will not steam well. 

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