Replica plane scaling visualisations (BF109 edition)

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Shayde

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I knocked these visualisations up quickly yesterday so I could get some idea of how each modeling scale looks. Posting here in case these are useful for anyone.

First up is the 50% scale. This is the scale the War Aircraft Replica planes use:

replica_50%.jpg

Next is 67% scale, or 2/3rds. This is the same scale the SAL Mustang uses, for instance:

replica_67%.jpg

Next is the 75% scale replica, as used by the Jurca MJ9. This is 3.375 times bigger in volume than the 50% and, roughly, so is the weight, and materials required (and, hence, the cost).

replica_75%.jpg

Now we have the 80% scale replica. 1.2x the volume of the 75%. I don't know of any replicas that have used this scale:

replica_80%.jpg

Next, just marginally bigger, is the 82%, as used for a Czech replica recently:

replica_82%.jpg

Finally, the big daddy, the 100%, as used by the real steel and the Jurca MJ90. 2.37 times larger in volume than the 75%. 1.95 times the volume of the 80%. A staggering 8 times the volume of the 50%:

replica_100%.jpg

And for our R/C friends, the 25% (1/4) scale:

replica_25%.jpg

I find being able to picture the sizes helps to know what the end result will look like.
 

Shayde

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I decided to play around with the pilot fit in the various scales, and I generated a new batch of pictures.

Let's start with the 100% scale BF109. This is the only scale in this post where the plane is big enough for the pilot to be looking down on her companion from her position in the pilot seat:

rep2_100%.jpg

Next up is the 80%. The reason I do this scale, despite no planes or plans using it, is this is the scale I'm most interested in building a replica to if the 100% turns out to be unachievable:

rep2_80%.jpg

Now we have the 75% scale, ala the MJ9:

rep2_75%.jpg

Next up the 2/3rd (67%) scale (SAL Mustang). This is the first scale where the pilot does not fit in the cockpit. Every image from here on, she's sitting with her butt on the very bottom of the fuselage, so bear in mind it will be even worse in reality once you add a seat, etc.:

rep2_67%.jpg

For Mr. Cluttonfred, the 5/8th scale:

rep2_62_5%.jpg

And now, the 50% W.A.R. scale, looking more like a Halloween costume than a plane at this stage:

rep2_50%.jpg

Interesting graphic, thank you for posting. That half scale seems to be impossible for a human to fit.

I agree with you. I admit I don't understand the W.A.R. planes. 50% just seems too small. At least in the case of the BF109 you simply cannot build the plane in this scale and still fit a human without altering the dimensions a lot somewhere. That seems to defeat the purpose of building a replica, to me.

You really need to do at least 75% scale for the BF109 if you want to keep the original shape.

You know, after doing all these, the original BF109's cockpit seems positively spacious - something I'm not sure gets said very often. :D
 

Twister51

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In your first set of pictures your 82% scale is really about full scale. And your "full scale" is way too large. If you've ever walked around a full size Me-109, one is immediately impressed with how small it is.
 

Shayde

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In your first set of pictures your 82% scale is really about full scale. And your "full scale" is way too large. If you've ever walked around a full size Me-109, one is immediately impressed with how small it is.

I'd imagine in a hangar, or a room full of other war planes, the BF109 looks small. But WW2 fighter planes are larger than you think, certainly a lot bigger than your average homebuilt. The BF109F is just under 9 metres long, or over 29 feet. If the 82% was the actual size anyone standing next to it could look down into the whole cockpit.

1663656888646.png

That's not what happens in reality.

1663656825865.png
 

flitzerpilot

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The above is quite fascinating and as someone who has always hankered after a scaled 109, it entirely matches my own thoughts on the subject. So in considering replicas I've considered 80% as the minimum scale for low wing monoplanes where, if one goes smaller, up close and personal, one winds up looking 'down' on the subject, which generates a 'toylike' impression of the aeroplane, totally at variance with what one is trying to achieve.

With biplanes, such as the excellent Avia B534 replica now being built (from these posts) the height of the upper wing has the opposite effect at reduced scale, where one has to look 'up' the the subject, even though the cockpit height above the ground may not differ from that of an equivalent scaled monoplane. This 'full size' effect is evident even with a non-replica type, such as my Flitzer biplane, which due to the long undercarriage assumes a 'grown-up' aeroplane aspect at ground level despite having a wingspan of only 18'.

On some of my other drafted designs such as the 88% scale Yak UT-1 or Polikarpov I-16, it is possible to increase the scale somewhat and still have a relatively small aeroplane, but with a generous cockpit size, especially with the I-16 due to the capacious fuselage.

I'll post a couple of images from my main computer archive to demonstrate these scales with human figures alongside for reference.
 

pylon500

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W.A.R. replicas did tend to deal with the larger fighters out there, Mustang, Corsair, Thunderbolt, Seafury, in fact the original W.A.R. plane, the FW190 is about the smallest of the lot, and you wear it more than sit in it.
I think Titan got it right with the size of the T-51, large enough to be impressive to stand next to but with a thick enough wing to be built light but still strong enough.
Once you got down to the 50% models, the thin wings required substantial spar caps which were disproportionally heavy for the size of plane.
The new Czech machines at 80% sounds a good balance. I had planned to follow the 'Flying Legend' Tucano at 70% with my PC-9, but wanted just a little more wing area to get my (ultralight class) stall speed, and ended up at 80%
 

cluttonfred

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Similar to Lynn’s comments about biplanes, I think that there are choices you can make in terms of the specific aircraft to model to help minimize those scale effects. For example, a Sindlinger 5/8 Hurricane would be more imposing and feel more realisitic if you chose to model a tropical variant with the big chin air filter.

7FCD2666-25AC-461B-A718-90CA2EE3F2DA.jpeg
 

Tiger Tim

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*in case anyone is wondering why that Sindlinger Hurricane is flying with the nose so high, I believe that photo was shot the evening it intercepted a Ju-52.
 

TFF

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Don’t think the War planes were scaled , they were styled. A person does have to fit, engines have to be picked, materials chosen too. That comes to the second point, size will depend on accessories available to ease the project. Most of scaling RC planes, especially commercial kits, wrapped around this. That’s why some could have some strange scales. Wheels and brakes. Those tend to be off the shelf. Engines are always a big issue. Canopy, although the 109 is probably the easiest. All the parts you don’t plan to make, you will need to choose before you scale.
 

Marc W

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I looked at building a scaled down Me-109 many years ago. After running a bunch of numbers I concluded the 80% scale was the minimum. It is possible to build a 80% model without distorting the shape. For example, I was able to lay a tape measure on the Me-109G-10 that Planes of Fame has at Valle, AZ. The cockpit rails measure 30" wide to the outside edge. 80% would be 24" which is as wide as my Thatcher CX4. I don't remember the fuselage depth at that point but it is deep enough to work. 80% gives a large enough wing to make stall manageable. The canopy might be the biggest problem since it isn't very tall. The best option for the canopy might be the Galland hood. The other problem might be the tall narrow landing gear. The landing gear was splayed out further on the late models so that would help.
 

flitzerpilot

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The attached shows a few designs including a 64% scale Fw 190 while the others are at a larger scale, but are still relatively small aeroplanes. Note that in both the UT-1 and I-16, the main spar is relocated at the deepest part of the wing profile which is advantageous and simplifies retraction in the case of the I-16. This of course was also a feature of my Fokker D.XXl (posted recently) which required stirrup blocks on the spar forward face as on the UT-1 to locate the undercarriage legs correctly.

The mainspar on the Fw 190 sweeps forward slightly as it does on the 109. The last diagram shows a potential retractable landing gear system for a lightweight 109. The undercarriage on the Fw 190 assumes a very long-legged appearance when extended, but to simplify the retraction system, rather than have the legs shorten as they retract (as on the F8-F for example) I was considering mounting them slightly further outboard than on the original a/c. This would contrive to reproduce the actual appearance of the machine on approach to land, rather than it's exhibiting a short-legged look.
 

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flitzerpilot

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Matt and Battler Britton, here's that same Sidlinger Hurricane, but not with the nose deepened for a Vokes filter, rather the upper line of the nose corrected and deepened which changes the visual impact by 'shortening the nose length' optically, much more in line with the real aeroplane. Windscreen is corrected as is the shape of the fin leading edge. Exhaust pipes have been raised in line with the upper part of the Continental cowling cheek intake and the nose could be further improved by fleshing out the underpart of that cheek - not shown here. Spinner is deeper and there's a subtle change to the rear decking line which is not 'swan necked' in reality.

Canopy lower edge has been raised while the top of the hood remains as designed so headroom is unaffected. Rand mast is made more erect.

All these changes are relatively easy to effect and I think the result is much more pleasing at that scale, although a slightly bigger scale would be preferable. I always though the Sidlinger Hurricane could be improved by these changes but was not sure how these might work until I saw that exact side view.
 

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flitzerpilot

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I'll oragise that shortly. I'll have to alter the camouflage scheme of course to represent Middle East Theatre! Of course, scaling it up a bit would help as I feel 5/8 scale is a little cramped. 75% scale would work for a Hurricane
 
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