Naked Science Forum
General Science => General Science => Topic started by: Geezer on 15/09/2009 05:37:15
-
My big brother had something called a Revojet (around 1955 I think). As I remember, it was really a sort of kite with rotating wings. It was really cool, because anything remotely associated with jets had to be cool in 1955! I remember him flying it on a beach on Orkney. The wind was so strong the string snapped. (Orkney is a dangerous place because you can get hit by airborne sheep.)
[diagram=520_0]
Anyway, why does a Revojet "fly"?
-
I can't say as I recall these Revojet thingys, but that's a fine piece of art. Have you studied da Vinci? (https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fbestsmileys.com%2Flol%2F4.gif&hash=dc0017defb1737ae43c0ff6efcb35b2a)
-
Yes, well very humorous I'm sure. But it's not intended to be artistic (although it obviously is). This is a serious piece of scientific research concerning the aerodynamic properties of sheep. Have you any idea how many sheep perish every year because they are blown into the North Sea?
-
Is it this ? ...
[ Invalid Attachment ]
Palitoys Comet Revojet in BOAC livery, plastic fuselage and wings, with control mechanism, string and bobbin -
Good Plus with a 54cm wing span in a Good illustrated box with instructions,
["Coronation" of Lizzy II was in 1953 (http://en.wikipedia.org/wiki/Coronation_of_Queen_Elizabeth_II)]
-
Amendment to diagram in the interests of scientific accuracy [:)]
[ Invalid Attachment ]
[How did you think they make tartan ?]
-
To ensure our sheepy doesn't get blown into the North Sea, I have devised a net to keep his high heels firmly on Terra firma.
[ Invalid Attachment ]
Its what I call a Barnet Bahnet.
-
Is it this ? ...
[ Invalid Attachment ]
Palitoys Comet Revojet in BOAC livery, plastic fuselage and wings, with control mechanism, string and bobbin -
Good Plus with a 54cm wing span in a Good illustrated box with instructions,
["Coronation" of Lizzy II was in 1953 (http://en.wikipedia.org/wiki/Coronation_of_Queen_Elizabeth_II)]
Yes. I think that's it. Note the image on the box actually looks like a de Havilland Comet, but, as I remember, the thing inside the box didn't. It could have been 1953.
-
Amendment to diagram in the interests of scientific accuracy [:)]
[ Invalid Attachment ]
[How did you think they make tartan ?]
Yes, that's a lot more accurate. I notice the sheepy is not exactly tartan yet, but I suppose that is taken care when the weave the multi-coloured wool into kilts and stuff.
-
... the image on the box actually looks like a de Havilland Comet, but, as I remember, the thing inside the box didn't.
The toy may not have resembled a Comet but was probably equally robust ...
http://en.wikipedia.org/wiki/De_Havilland_Comet#Comet_disasters_of_1954
BTW here is where I found the image of the box ... http://www.vectis.co.uk/auctiondet.php?item_id=410800
-
Polite Notice From The Desk Of Sheepy:
Please keep an eye out for anything ewe deem libellous !
There has been a spate of libellous posts going on. Fortunately I am a sharp sheepy and nothing gets past me !
-
These are great posts... LOL... Love the artwork and the quotes.. by the way I had never heard of the Revojet from the past but that looks like about the right time frame in the pictures Rd Posted...nice information RD.
-
Polite Notice From The Desk Of Sheepy:
Please keep an eye out for anything ewe deem libellous !
There has been a spate of libellous posts going on. Fortunately I am a sharp sheepy and nothing gets past me !
Yes, he is quite the sharp Sheepy!
Nothing gets past him least it be a very sexy Ewe... He just melts like a popsickle in the sun! LOL.....
-
The toy may not have resembled a Comet but was probably equally robust ...
http://en.wikipedia.org/wiki/De_Havilland_Comet#Comet_disasters_of_1954
Yes. Metal fatigue was not so well understood then. Shame, because they were really great planes. I've flown on them several times.
-
I once attended an exhibition at the Comet Hotel in Hatfield. Alas, now, even the hotel has been renamed ! *le nostalgic sigh*
-
Lol...
[ Invalid Attachment ]
Goodness me, that's the worst drawing of a D.H. Comet that I've ever seen [:D]
The wings are almost the right shape but are back-to-front, and the engines weren't out on the wings, with a gap between them, but were right next to each other and located in the wing roots.
-
Lol...
[ Invalid Attachment ]
Goodness me, that's the worst drawing of a D.H. Comet that I've ever seen [:D]
The wings are almost the right shape but are back-to-front, and the engines weren't out on the wings, with a gap between them, but were right next to each other and located in the wing roots.
You're right. The wings are backwards! LOL
-
Lol...
[ Invalid Attachment ]
Goodness me, that's the worst drawing of a D.H. Comet that I've ever seen [:D]
The wings are almost the right shape but are back-to-front, and the engines weren't out on the wings, with a gap between them, but were right next to each other and located in the wing roots.
I just noticed that the windows in the drawing appear to be, prophetically, round. Had the actual aircraft copied the Palitoy illustration instead of using square windows, the disasters might never have happened.
-
Lol...
[ Invalid Attachment ]
Goodness me, that's the worst drawing of a D.H. Comet that I've ever seen [:D]
The wings are almost the right shape but are back-to-front, and the engines weren't out on the wings, with a gap between them, but were right next to each other and located in the wing roots.
You're right. The wings are backwards! LOL
Could it be that this model was of the erstwhile now defunct " Comet Reverse ". De Havillands attempt at a backwards flying Comet ?..yes..yes..I am sure this is true !!
-
Here's a link that reveals what is inside the box. Pretty cool, eh?
http://www.astonstoyauctions.co.uk/images/lots/090730/407.jpg
-
Maybe the backwards wings were to avoid breach of copyright: it's similar to the Comet but not the same,
(the word "Comet" would not be protected by patent/copyright but its image would be).
Re: original question
I think the Magnus* effect may be responsible ... http://wapedia.mobi/en/Magnus_effect#5.
(* Nothing to do with Dr Pyke, although his arms almost moved sufficiently to cause flight (http://www.youtube.com/watch?v=2IlHgbOWj4o) [:)] )
-
Great! Thanks. That looks like the explanation.
It also might explain the airborne sheep phenomenon too. Presumably if you can get a sheep to spin fast enough about its axis it would experience some aerodynamic lift. Would you think?
I seem to remember my brother's Revojet had more of a Dan Dare look to it than a D H Comet. Perhaps that was after some of the disasters and Palitoy thought it wise to distance itself, or maybe D H went after Palitoy for infringement. I'm pretty sure my Dad recorded the Revojet flying on 9.5 mm film. I'll ask my brother if the film survived. It would be nice to put it on Youtube.
-
I just noticed that the windows in the drawing appear to be, prophetically, round. Had the actual aircraft copied the Palitoy illustration instead of using square windows, the disasters might never have happened.
Indeed. How ironic is that?
-
Maybe the backwards wings were to avoid breach of copyright: it's similar to the Comet but not the same, (the word "Comet" would not be protected by patent/copyright but its image would be).
Copyright wouldn't have been an issue with regard to images of the aircraft as it is not the appearance of the aircraft that has been copyrighted but its design. Were appearance to be copyrighted it would prevent anyone from producing photographs, paintings or drawings of anything that was manufactured. The one exception to this, that I've heard of, is the display of lights on the Eiffel Tower. In this case, it is not the design of the bulbs, the control system or the way that the lighting has been implemented that has been copyrighted but the particular pattern that the lights make, but then in this case it is precisely the appearance that counts.
The 'Comet' name is, or would have been, copyrighted though. Funnily enough, a U.S. company has claimed the copyright on the name 'Liberator' and has objected to flightsim developers using the name 'Liberator' for their B-24 models. Quite how this company acquired the copyright is a bit of a mystery to me, as the name 'Liberator' originated with the RAF and was only subsequently adopted by the USAAC. Consolidated, who made them, just called them B-24s.
-
Copyright wouldn't have been an issue with regard to images of the aircraft as it is not the appearance of the aircraft that has been copyrighted but its design. Were appearance to be copyrighted it would prevent anyone from producing photographs, paintings or drawings of anything that was manufactured.
A drawing / painting “inspired by” a copyrighted design would be a derivative work (http://en.wikipedia.org/wiki/Derivative_work) and could infringe the original copyright if not sufficiently different from the original.
The 'Comet' name is, or would have been, copyrighted though.
If that was so everytime Sir Patrick Moore used the word "Comet" in his astronomy books he would have to obtain permission from the copright-holder and pay a reproduction fee to use the word.
-
I really "luffed" (as Neil might say) Patrick Moore. (Not in the Biblical sense, you understand.) I did not intend to launch a legal debate. That might best be conducted at www.nakedlawyers.com
-
I really "luffed" (as Neil might say) Patrick Moore.
Should be "luff": he's still at it ... http://www.bbc.co.uk/science/space/skyatnight/proginfo.shtml
-
Copyright wouldn't have been an issue with regard to images of the aircraft as it is not the appearance of the aircraft that has been copyrighted but its design. Were appearance to be copyrighted it would prevent anyone from producing photographs, paintings or drawings of anything that was manufactured.
A drawing / painting “inspired by” a copyrighted design would be a derivative work (http://en.wikipedia.org/wiki/Derivative_work) and could infringe the original copyright if not sufficiently different from the original.
This would be true only if the copyrighted design was also a drawing/painting. For copyright to be infringed in the case of an aircraft, the derivative work would also have to be an aircraft. In this case, when we compare the two works, we find that one work is an aircraft and the other work is an image so there's no possibility of mistaking one for the other; you wouldn't try to board a picture to fly somewhere and you would try to hang an aircraft on your wall.
The 'Comet' name is, or would have been, copyrighted though.
If that was so everytime Sir Patrick Moore used the word "Comet" in his astronomy books he would have to obtain permission from the copright-holder and pay a reproduction fee to use the word.
Ok - I'll treat this comment seriously. Copyright doesn't apply to words but names. If you started marketing a computer operating system named 'Windows' MS would come down on you in an instant, but they can't stop people from incorporating windows in their homes, or indeed, companies that make window frames/window parts from incorporating the word 'windows' in their company name e.g. Premier Windows Ltd. (this is a real company, but I won't include a link to prove it as it would be spam). Microsoft can't even prevent other computer operating systems from using features named 'windows' in their interfaces.
Attempts have been made to copyright words, and even letters: Microsoft tried to copyright the word 'Windows' and Intel tried to copyright the letter 'i', but both failed, of course. One of the reasons that Intel switched to naming their processors after the 80486 was because they couldn't copyright numbers and thus prevent other processor manufacturers from calling their x86 compatible chips '486', '586' etc. On the other hand though, Microsoft was able to prevent another company from calling their particular Linux distro 'Lindows' as it was deemed to be too similar to 'Windows'.
-
This would be true only if the copyrighted design was also a drawing/painting.
The aircraft would be constructed from engineering drawings, which would be protected by copyright.
The words "Microsoft" and "Windows" are trade marks, not same as copyright.
http://en.wikipedia.org/wiki/Trademark#Comparison_with_patents.2C_designs_and_copyright
-
This would be true only if the copyrighted design was also a drawing/painting.
The aircraft would be constructed from engineering drawings, which would be protected by copyright.
Are you really suggesting that the illustration on that box could be mistaken for an engineering drawing? What point were you really trying to make there?
The words "Microsoft" and "Windows" are trade marks, not same as copyright.
http://en.wikipedia.org/wiki/Trademark#Comparison_with_patents.2C_designs_and_copyright
Indeed, but it was you who started referring to copyright, so I stuck with it to avoid confusing you further.
-
I really "luffed" (as Neil might say) Patrick Moore.
Should be "luff": he's still at it ... http://www.bbc.co.uk/science/space/skyatnight/proginfo.shtml
That's great! Thanks. We don't get him on the telly here.
-
I don't know if anyone is still interested in Revojets after all this time, but the Coronation Revojet was the last of a series of kites with rotating wings, and came out in the summer of 1952.
Before that there was the standard version that didn't pretend to look like an aeroplane, which was white with diagonal pink stripes! I was very disappointed when they brought out the improved, de luxe, and more expensive model, just after I bought my standard one. The Coronation version originally had one red wing and one blue wing. Everything was red white and blue just before the Coronation the following year.
After the coronation, they blocked out "Coronation" on the box artwork, substituting a large "Palitoy" logo, and the wings reverted to white. You got s spare set, too, and a little man with a parachute who could slide up the line and jump off at the top!
Before the pink striped common version there was a smaller design in a much smaller box - so small that it wouldn't fit in the box unless you took out the wing wire and disassembled it.
A couple of years ago I found a modern copy in the beach-toy section of a French supermarket. It was very similar to the standard version, but had a free-wheeling propellor at the front.
I have about fifteen Revojets of various types, and one day I may try to get a photo of them all flying at once.
The possible resulting tangle is a bit of a worry, though.
It would be easier to do it in Photoshop!
Love the sheep artwork!
I think the answer to the original question of how it works is Bernoulli's principle.
Lift from rotating cylinders.
There's a definitive answere in a NASA site www.grc.nasa.gov/WWW/K-12/airplane/cyl.html
If I knew how to attach photos I'd have posted one of the earlier types.
Don't go by the artwork on the box for the Coronation Comet version - it looked nothing like it, and rather more like the Comet aeroplane, though with symmetrical wings, as they had to rotate.
-
I had one of the original style Revojets in the early 50s it was pretty poor as a kite and needed a moderate steady wind to keep it airborne pity there are no pictures of one here so I have added one
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2F%5Battachment%3D12649%5D%5B%2Fattachment%5D&hash=c2c39daac140ec99967a8da536bf45ad)
It is interesting to note the sort of "fishing rod" that you used to control it.
I flew it all day at southport once and it was never the same again because the bearings had worn so much
-
So glad someone is still following this topic.
Trying to upload the photos.
[ Invalid Attachment ]
Two examples of the small early version.
[ Invalid Attachment ]
The standard pink and white version
[ Invalid Attachment ]
Nose of the Comet, parachutist to right
[ Invalid Attachment ]
Modern French example.
We'll see if that worked.
-
Nice pix! Thanks Scadoo.