AVITime On Your Hands
Thanks for info, its for a modelling project of mine.
I am trying to do an accurate scale model of a mark 1, so i need to get the proper dimensions and scale them down.
Do you think the owners of the XP-51 could give me that info?
Kev35 nice to see you have lots of time on your hands, shame i dont.
Thanks for the help
XH668: Shame you don’t have lots of time on your hands …..
Do you have any idea of what’s involved in chasing down examples of the P-51, obtaining permission to photograph and take measurements off them, and the amount of research into the construction of the aircraft it would take in order for you to develop your own accurate scale drawings?
When you’ve got the measurements, and I’d be most interested in the techniques you’d use to accurately obtain them, how are you going to do the drawing, loft the fuselage bulkheads, plot the airfoil stations, etc.? Are you going to do your drafting manually or are you going to spend the time to acquire CAD skills?
Please don’t think for a minute that I’m trying to discourage you. In fact, I myself have spent a number of years researching a certain well-known military trainer, taking photographs and measurements in order to develop my own drawings. I’m simply curious as to whether you fully understand what you’re getting into.
My project initially began with a photo copy of a page out of an issue of Janes because I could find no accurate drawings for the aircraft of my choice. (There still aren’t any accurate drawings available.) The page in Janes listed the aircraft specifications and included a tiny three-view drawing that in my naivety I believed could be enlarged with sufficient accuracy. How wrong I was! That was a number of years ago and the beginning of a journey which along the way, rudimentary CAD skills were acquired, along with a wealth of knowledge concerning this particular aircraft. We’re talking years here!
Are you willing to invest an enormous amount of time? And acquire the necessary skills?
As a matter of fact, it would be an interesting new thread to hear from enthusiasts who have done just that; people who have measured actual aircraft and have developed accurate scale drawings on their own. It would be interesting, for example, to find out and compare the various methods and techniques used in obtaining accurate measurements.
How is it done?
Do you jack up the airplane and drop plumb lines onto the ground? How do you measure a fin and rudder when you’re standing on the ground? How do you obtain fuselage contours and bulkhead cross-sections?
Anybody out there want to jump in on this?
AVIScale Drawings
If you’re building a model of the P-51 try Googling Arthur Bentley. He sells scale drawings of a number of aircraft, including the P-51. Arthur’s drawings are virtual works of art, the best, bar none!
Here, I’ve done it for you!
AVIPretty Airplane
It’s definitely one with classic lines!
Pretty airplanes usually fly as well as they look.
Superfluous to mention the Spitfire and P-51 as examples.
How was the F2H from a pilot’s viewpoint?
AVIHappier Times
Fatal crash 1998. Apparently low speed pass with subsequent stall/spin. An old friend.
AVIOnce Pristine
This one was once pristine.
AVINothing Fancy
Old-fashioned brush and paint on 24″X36″ aluminum panels. Two panels of a series.
AVIPSRU
Try this guy: Algie Composite Aircraft. He’s doing an LS1 powered carbon aircraft that he’s going to kit and to race. Got some good stuff on his website.
http://members.iquest.net/~aca/
Good luck on your project.
AVIElliptical Wing
Tom, ran across this and thought it might be of interest to you:
http://www.homebuiltairplanes.com/forums/showthread.php?t=3559
AVILand of Oz
One grandfather was born in Oz late 1800s http://forum.keypublishing.co.uk/images/icons/icon6.gif
Cool
AVIWeight & Balance
Tom:
Ever get a wood splinter in your finger?
There are many successful composite homebuilts and production aircraft flying.
The granddaddy of them, the Long EZ has been around for close to thirty years!
For homebuilts you don’t need autoclaves. There are also methods that are moldless although admittedly, plugs and molds are the way to go.
Homebuilt aircraft are not stuffed into huge, expensive autoclaves! Check out homebuilt glass/carbon. It might surprise you.
Did you say that there’s a hundred-and-thirty pounds of ballast in the T-Spitfire nose? If that is correct, that should tell you something. The fighter pilots of fifty/sixty years ago were not the 300 lb, overweight, macho guys brought up on a diet of McD’s that fly the friendly skies of today. (Sorry guys.) Back then, they probably weighed all of 130 pounds soaking wet!
And not just airplane guys – many of today’s youngsters find it impossible to stuff themselves into the driver’s seat of an original Colin Chapman Lotus 7 !!
Everything is supersized today, including aircraft cockpits.
Ask some of the Spitfire guys on the forum. I’m sure they can give you the lowdown on the ballast.
What’s installed behind the pilot on a Spitfire? Radio equipment, a huge compass, but what else? The reason I’m asking is that maybe the GIB is so far back in the fuselage because there wasn’t room for him and all the equipment tucked up behind the guy in front. How much did all that crap that was located immediately behind the pilot weigh? And how much space did it take up?
Check out the two-seat Sea Fury, Yak 3, and P-51 conversions. Not wartime P-51 hacks but modern day conversions. The GIB is tucked up behind the pilot on P-51s because the original monster-size radios and fuselage fuel tank are sh*tcanned. On present day P-51s (with exception of those restored to original wartime specs) modern nav/radio equipment is stacked in/under the instrument panel and there is no fuselage tank. (which, BTW, created much instability when full) What was the size of the P-51 fuselage tank? How many gallons? I would venture to say the weight of the fuel would have exceeded the weight of a GIB.
You might be able to tuck the backseater right behind the pilot under a slightly extended canopy. But I think you’re still going to have to deal with the problem of the extended nose that was originally stuffed with howevermanypoundstherewere of Griffon.
AVIDetachable Wings and the GIB
Good choice, Tom, with the Mk XIV loback. Pretty airplane. Have you considered the Mk XVIII with its larger vertical tail?
My $0.02 worth: The primary reason a one-piece wing is used more often than not is for the simple reason that it will end up much lighter than a two-piece wing with heavier spar and spar attach hardware. Weight is one big enemy. It’s also easier to align.
As for the GIB, it is theoretically possible to place him/her behind the pilot, but what others have found is that one of the big challenges with w/b and warbird replicas is the long nose and much lighter weight of a V8, especially an aluminum LS2. You’ve got one long moment arm there and the LS2, unlike the length of the airframe, most likely won’t scale to 70% Merlin weight.
Yes, as previously mentioned, there’s the placement of fuel to consider and couplings, etc., but there’s also the landing gear attach points.
Personally, I’d say build a one-piece wing, even if you have to rent a hangar.
And secondly, why not build with composites? Build time with composites will be faster and given the cost of quality aircraft grade wood these days, probably less expensive in the long run.
If you’re going to build with wood, why not save yourself a bunch of time and build from one of the plans sets available? The designers have already done the math – all you have to do is to build. Purchasing a couple of sets of plans will be money well spent!
Check out the Falco from Sequoia in Richmond, VA – it’s a wonderful wood homebuilt, with a one-piece wing.
AVIAerolite Spitfire
Spitfire the History – Eric Morgan & Edward Shacklady
Pages 123 – 126 The ‘Aerolite’ Spitfire.
AVISurprise
Digby
The 22swg Spitfire skins are made from ‘unobtainium’ or as our US cousins call it – ‘unobtainum’. 😉
Mark
Surprise! Although aluminium is quite correctly “aluminum”, unobtanium is also very “unobtanium” over here in your former colonies. :)-
AVIWings
OK, Tom, here I go again. Why don’t you check out some homebuilt websites such as the KR2 and the Thorpe? You might also want to examine the Spitfire wing as a whole assembly instead of placing your entire focus on the spar. If you obtain a clear understanding of how the wing goes together and the function of each separate component along with the loads and stresses, it might make your job of designing the spar much easier.
What I’ve been asking is: “How is one able to competently design a spar until one has a clear understanding of the separate and combined functions of the spar caps and web, including loads and stresses, and calculations of the size and weight of the aircraft and wing?” Simply scaling a full size Spitfire wing down to 70% may not be a workable solution. Without doing the full calculations, how can you be certain whether it will work or not?
On the other hand, there is a very good chance that even if you work out what you believe to be the perfect method to manufacture a homebuilt spar on this very forum you may discover to your chagrin at a later date that it won’t work at all without huge modifications.
If your intention is to build a scale, flying Spitfire using similar materials, I would respectfully suggest that you first examine and dissect the entire structure of the Spitfire, down to the last nut and bolt. Become a Spitfire “expert”.
Then draw out the fuselage, wings and empennage to scale. You don’t have to do it full size – a 20% drawing (of your 70% scale airplane) will show you very quickly how much room you’ll have in the engine compartment, how much space there will be in the cockpit (hope you’re not 6″ 5″/300 lbs) and how thick the airfoil will be where you intend to place the spar. Don’t forget, the landing gear has to fit as well.
Next you’ll have to decide on the powerplant in order to work out the moments, wing area, and tail volume. Who knows, you might have to increase the scale size wing or increase the tail volume/areas. Or, as with Mk1, discover that substantial nose ballast will be required. ( Incidentally, this is apparently far from uncommon with scale warbirds.) This is another good reason why you might want to investigate the possibility of building a later mark Spitfire with the longer Griffon nose and larger tail, especially if it’s exact scale that you’re insisting on.
When you have the wing drawn in you can then work on the sizing of the spar(s) and attach points.
The D-section of the Spitfire wing has been previously mentioned on this thread. That makes for a strong wing. Does the Spitfire wing have a rear spar as well? If it does, you might be looking at another box section here. Great. How was the Spitfire wing attached? I know there was a huge spar carry-thru on the firewall, almost as massive as that found on the Hurricane. You might want to study those. The F4U Corsair has a massive, and I mean massive, curved center section spar that runs across the fuselage and wing center section to the landing gear and outer wing attach points. How did Vought tackle this huge component?
Somewhere on the internet, there’s a guy building a replica Corsair using a milled center section spar. You might want to google his website for information.
There’s a lot of work involved in designing and building an airplane, The good news is that it’s been done before and a replica Spitfire is 1940s and 1950s technology so the answers are there. It isn’t like trying to design and build a space shuttle. There are many good books available and much information on the internet. Much of the fun in doing this is the process, the ongoing studying and learning process.
Cheers and Good luck – I’m just about lectured out! :)- Time for me to get back to my research!
AVI
PS – my project began with me trying to scale up a tiny 3-view drawing from an old issue of Jane’s which was all I had to work with at the time. It didn’t work.
AVIAmazing!
Neither… No transaxle in the car. I’m mounting the Jag “the right way”,connect it to a modified Dodge Viper T56 gearbox (modified to 5 gears,not 6 and reverse shift pattern) and a custom “gearbox” in front makes me able to have the mainshaft running back below the engine/gearbox combo (custom sump/bellhousing) and into a Toyota Supra rear diff… Closest you can get to the original layout of the car,without buying the actual engine and gearbox… But,we’re OT… 😮
Wouldn’t it be cheaper to buy a used Lambo like an older Countach?
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