Nice Shots

Nice Shots, Anna!
Really liked the Hunter and P-51!
More …..

Timeless …

Nothing quite as beautiful as Stelio Frati’s SF260 !
He must have been inspired by the P-51 …

Scale Effect

One other thing to bear in mind – and I am sorry if I am teaching anyone here to suck eggs – is that scale flying models do not generally use exact scale copies of the original aerofoil sections simply because the characteristics of a 1/5 scale aerofoil in 1/1 scale air are not usually the same as a 1/1 scale aerofoil in 1/1 scale air.
Often the aerofoil needs altering to obtain acceptable take off and landing speeds and to avoid undesirable handling characteristics in a model as well.
I think this all a bit of a black art but those who are heavily involved in scale flying seem to manage to sort it out pretty well.

This holds true for most 75%, 80% flying replicas as well. Subtle changes often have to be made not only to the airfoil section but to the wing planform and tail surface volume. It’s also difficult to fit a 100% modern-day, 250 lb McAviator into a 75% cockpit, or as the gals call it today, a “boxoffice”, so the fuselage also has to be tweaked. Building replicas to 100% scale makes more sense but then a suitable powerplant has to be sourced. Then it usually becomes a hi-dollar project …

Scale Drawings

I personally wouldn’t scale anythin up from a model. It is also bad practice to scale up from small scale drawings too in a drawing office. Just the thickness of a 1mm pencil line at 1/24, becomes 24mm thick full size. So even if at 1/24 scale drawing was 100% accurate, you will still get an approximation at full size.

The only true way to do these things are to get the original co-ordinate plots (lofting lines) for an aircraft from the original manufacturer. John “Aeroclub” is spot-on here: The Hornet for example has had its length incorrectly stated in the 1946 and re-produced as fact ever since! This was not helped by the fact that AP’s gave packaging dimensions for major sub-assembly parts of the Hornet with an allowance for clearance too!

Even when you have some original drawings and some small pieces of distorted wreckage, creating full size drawings of something the size of a Stirling can mean errors of several inches could appear just by drawing a line to the information you have, which may or may not be ok?

As Dave mentioned above. A simple error of 1mm can be greatly compounded. So far, the discussion has revolved around plastic scale models but what about the larger 1/5 or 1/4 RC models or even a 75% or 100% scale replica?

Let me back up a bit …. for a number of years now, I’ve been developing my own 100% scale drawings of a well-known military trainer, trying to get the drawings accurate down to the last millimeter.

My initial research began with photocopies of a couple of pages out of an old issue of Janes which included a tiny 3-view drawing of the aircraft. Well, as naive as I was back then, I actually believed that I could blow the 3-view up and create working drawings with the help of photographs and the published specifications. Right! :)-

Next was a serious attempt to obtain accurate scale drawings. The manufacturer was of no help, declining to provide material by claiming a proprietary interest, but over the course of a couple of years, several scale 3-view sets of drawings that had been published in various model magazines were obtained. However, not one single set of drawings was accurate in outline. They varied from pretty good to downright lousy! So … back to the drawing board ..

A major break came at a military airshow when the owner of an example of the aircraft was kind enough to grant permission for me to crawl all over the airplane, taking measurements, photographs, and making sketches. (This was the first occasion of seeing the aircraft in the flesh, and my initial impression was how tiny it actually was.) Since then, I’ve taken measurements off various examples of this aircraft.

Over the past few years I’ve managed to examine a half dozen of the aircraft, taking more measurements, making more sketches, and taking many more photographs. The problems involved with accurately measuring a full-size airplane are immense and deserve a tread of it’s own on this forum. Those who have actually attempted to do this, I’ve discovered, usually have access to the aircraft while it is sitting propped up and level, and from what I understand, plumb lines are dropped and measured on the tarmac. Then there’s got to be a way to take measurements of the fuselage bulkheads and airfoil shapes. Yeah, a lot of work, and unfortunately it’s usually impossible to find an example propped up under ideal conditions for taking measurements. And don’t forget the helpers. It’s not easy measuring an aircraft on your own.

Next we come to research. We’re really talking about detective work here. The amount of research required to develop accurate scale 3-view drawings is absolutely staggering! Especially when the drawings are to full 100% scale and must be accurate down to the last silly millimeter. (How guys like Arthur Bentley did it before CAD is beyond me!) Factory manuals are a great help here, but much factory information is incredibly misleading and may have been intentionally misstated by the manufacturer, perhaps in order to protect proprietary information. Whatever the reason, there are many critical errors. An example for this particular aircraft was the root chord. We normally measure the wing root chord at the aircraft centerline. Not these guys!! And the tip chord wasn’t at the tip either! Go figure!
But if factory drawings showing the fuselage and wing stations can be obtained, they are invaluable. A set of factory maintenance manuals is priceless. It would be difficult to complete the drawings without them.

The unsuspecting can easily be thrown off track … such things as a spinner modification, either a longer or shorter spinner can throw the overall length off quite a few millimeters or inches. The list goes on.

Bottom line, unless you’ve got a draftsman who’s cross-referenced factory drawings with actual measurements taken off aircraft such as the Spitfire drawings offered by Monforton Press http://www.monfortonpress.com/ and drawings by professionals like Arthur Bentley http://www.albentley-drawings.com/ scale 3-view drawings may vary from pretty accurate to being absolutely lousy. It would be foolish to presume that drawings for a 1/48 plastic kit were 100% accurate.

Google Translation

Propstrike,
The Google translation leaves a bit to be desired …. “car” is machine, and “cover glass bell” is clear canopy …. but it does give one the overall gist of the article. Rather than the Mig being restored from one small cog, we’d probably say that it was restored “down to the last nut and bolt.”

The Truth

Ah thank you. I knew someone would come up with the truth. Saves me digging through my reference material later.

You’re welcome.
However, beware of what you read – perception is the truth … :)-

Dream Machines

While we’re on the dream list, how about a show with a Westland Whirlwind and a DH Hornet?
Throw in an F-82. (and yes, it had Allisons – not Merlins)