10/23 Raptor Video

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flywheel1935

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New video up! He is installing an engine with 45k miles on it. I was thinking.... if he intends to build thousands of raptor kit planes why is he using this engine? It's no longer in production so how will he obtain the engines for his plane?
Don't worry, THERE WILL NOT BE THOUSANDS OF RAPTORS !!!!! like all dreamers, at some point they wake up, and get back in the real world ( If they're lucky) my money is 5 Raptors, then ,Puff, Gone. 🤪
 

TarDevil

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THERE WILL NOT BE THOUSANDS OF RAPTORS !!!!!
Huh uh, can't be true! There's at least a thousand YouTubers dying to give Peter their money.

LOL! But to Rick's point, Peter thinks so. So why would Peter make a production decision based on a limited resource when he believes the sky will be thick with Raptors?

I guess Peter thinks the overwhelming demand is enough for Volkswagen to resume production.

Peter isn't brain dead (stubborn, yes), I'm convinced at this point he's knows he's just a professional YouTuber.
 

BBerson

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Tenacity combined with good judgement and execution can give good results eventually
Right. I think tenacity isn't the ideal word for ignoring advice.
I consulted my wife who was an author and she suggested obstreperous:
2: stubbornly resistant to control.

Or obstinate is perhaps closest:
Definition of obstinate

1: stubbornly adhering to an opinion, purpose, or course in spite of reason, arguments, or persuasion.

Or obdurate:
Definition of obdurate

1a: stubbornly persistent in wrongdoing an unrepentant, obdurate sinner
b: hardened in feelings The obdurate enemy was merciless.
2: resistant to persuasion or softening influences obdurate in his determination
 
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flywheel1935

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Peter isn't brain dead (stubborn, yes), I'm convinced at this point he's knows he's just a professional YouTuber.
As I've posted before, he's a better Steven Spielberg, than a Burt Rutan.
Even Cirrus went back to 'Tractor' aeroplanes to achieve mass sales, despite GA being a 'forward thinking' environment, established types still prevail, my dream aircraft is a Carbon Cub,( but then I drive a 1935 car) 🤭
 
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TarDevil

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Right. I think tenacity isn't the ideal word for ignoring advice.
I consulted my wife who was an author and she suggested obstreperous:
2: stubbornly resistant to control.

Or obstinate is perhaps closest:
Definition of obstinate

1: stubbornly adhering to an opinion, purpose, or course in spite of reason, arguments, or persuasion.

Or obdurate:
Definition of obdurate

1a: stubbornly persistent in wrongdoing an unrepentant, obdurate sinner
b: hardened in feelings The obdurate enemy was merciless.
2: resistant to persuasion or softening influences obdurate in his determination
...or as my wife says: "All the above."
 

PPLOnly

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New video up! He is installing an engine with 45k miles on it. I was thinking.... if he intends to build thousands of raptor kit planes why is he using this engine? It's no longer in production so how will he obtain the engines for his plane?
They all say “45,000” miles on eBay so I’m skeptical. And 45,000 miles is 1,000-1,500 hours. I realize car cycles are mostly low load, low RPM but it’s kind of a lot even if you believe the low mileage of the advertisement.
 

PPLOnly

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Why does he have those vortilons at the ends of the wings if they can just be shaved down?
 

Marc Zeitlin

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Why does he have those vortilons at the ends of the wings if they can just be shaved down?
They're fences, not vortilons. But in any case, they're supposed to minimize spanwise flow near the wingtips, for stability and deep stall prevention reasons. It's not at all obvious (or analyzable) what the optimum height of the fences should be - the previous size was arbitrary. So it's possible that the slightly shorter ones will work exactly the same (or at least within measurement accuracy) or that they won't be as good (highly unlikely that they'd work BETTER being smaller).

Since it wasn't clear that whatever height they were before was the "right" size, it's hard to say whether it's OK or not OK to make them 3/4 the size. Smaller can't be better, but it might not be any worse. If the plane's less stable in roll (or dutch roll), that'll be one possible answer. If it deep stalls at an AOA that it hadn't deep stalled previously, that would be another answer. But since he's never stalled the thing, much less gotten close to a deep stall, the second supposition is purely theoretical.
 

PPLOnly

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They're fences, not vortilons. But in any case, they're supposed to minimize spanwise flow near the wingtips, for stability and deep stall prevention reasons. It's not at all obvious (or analyzable) what the optimum height of the fences should be - the previous size was arbitrary. So it's possible that the slightly shorter ones will work exactly the same (or at least within measurement accuracy) or that they won't be as good (highly unlikely that they'd work BETTER being smaller).
Fences are only on the tops of wings I thought, and vortilons are on the bottom. I also don’t believe it’s arbitrary, you can analyze how tall they need to be in wind tunnel or model testing.
 

AdrianS

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Fences are only on the tops of wings I thought, and vortilons are on the bottom. I also don’t believe it’s arbitrary, you can analyze how tall they need to be in wind tunnel or model testing.
Yeah, but this is Raptor. PM doesn't appear to believe in any form of testing except flying in circles, as far as I can see.
 

wsimpso1

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Fences are only on the tops of wings I thought, and vortilons are on the bottom. I also don’t believe it’s arbitrary, you can analyze how tall they need to be in wind tunnel or model testing.
Many of us need to learn how to read the shorthand.

First, I would not argue with Mister Cozy about nomenclature on canards or how the dimensions of these various fixes applied to these ships were arrived at. His help and insights are valuable - we want them to continue.

Arbitrary in an engineering sense indicates that randomness was a large player in the sizing and/or positioning of the devices.

Likely situation is that someone had a problematic characteristic present, says "I bet if I did this, it would be better", the design space is eyeballed options thought about, some scheme is tried out, and the problematic characteristic was so much improved, they went on to the next biggest problems they had. Optimization occurs when negative and positive traits both occur and you still NEED to reduce bad and/or increase good characteristics. In many engineering environments, you fix the biggies and move on until there are no more biggies. You only optimize things that have enough importance to justify it.

What is being said appears to be:
  • Sizes were guessed at;
  • No effect of size nor optimization of size/shape was done;
  • Analysis of this sort of device is currently not fruitful;
  • Confirmation that the current ones work adequately was not conducted;
  • Effects upon characteristics of this airplane from reducing the dimensions are thus unknown.
Shorthand lesson is ended.

Billski
 

Marc Zeitlin

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Fences are only on the tops of wings I thought, and vortilons are on the bottom.
While the general canard community today refers to the small protrusions at the LE, below the stagnation point as vortilons, and to large flow oriented "walls", either top or bottom of the wing, usually at the TE but not always, as "fences", the standard terminology does align with your thinking - vortilons below, fences on top. So the thing underneath the tip of the Raptor wing could be referred to as a full chord vortilon (terminology I've never seen before).

I appreciate Billski's defense, but in this case, it seems as though PPL was more correct in terminology, common canard community phraseology notwithstanding.

I also don’t believe it’s arbitrary, you can analyze how tall they need to be in wind tunnel or model testing.
My reference to "arbitrary" was in the context of the one airplane we're discussing here - the Raptor - on which no aerodynamic CFD analysis was performed, no wind tunnel testing performed and essentially no flight testing performed. Sure - CFD and wind tunnel testing might give some reasonable estimate of what the shape of any spanwise flow control device should take, but none of that was done here - hence the "arbitrary" label.

The Raptor aircraft has lower surface "full chord vortilons" at the tip because the marginally tested scale model had terrible flight characteristics until the FCV's were installed on it. Jeff Kerlo convinced PM to install them on the full scale Raptor wings as well due to that small amount of testing. But if you think there was any analytical basis for the previous shape or size, I've got a bridge in Arizona you might be interested in :) .

Billski's explanation is about it.
 

edwisch

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It is not the critic who counts, not the one who points out how the strong man stumbled or how the doer of deeds might have done them better. The credit belongs to the man who is actually in the arena, whose face is marred with sweat and dust and blood; who strives valiantly; who errs and comes short again and again; who knows the great enthusiasms, the great devotions, and spends himself in a worthy cause; who, if he wins, knows the triumph of high achievement; and who, if he fails, at least fails while daring greatly, so that his place shall never be with those cold and timid souls who know neither victory nor defeat.Teddy Roosevelt
 

Vigilant1

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The Wright brothers had some important attributes:
- They valued the hard-won experience of those who came before them, and went to great lengths to build on that knowledge rather than repeat the mistakes of others. In short, they respected prior art and those who created it.
- They were disciplined experimenters and careful observers who methodically gained knowledge in every area needed to bring success to their project. They tried new things and made improvements according to a plan.
- They sweated the details.
 

rv6ejguy

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edwisch,
How hyprocritical of us to praise the Wright brothers and then vilify our modern day pioneers.
Jeff Liot
The Wrights were true pioneers, nobody before them did what they did. Peter isn't pioneering much of anything here. Several homespun automotive diesels have been flying successfully in Europe for well over a decade, hundreds of belt redrives for more than 2 decades, canard aircraft for over 100 years, pressurized aircraft for 80 years, I could go on.

The thing with Peter is, he hasn't learned much from all these previous airplanes and designs, thinking he is smarter than all these other people before him, even though he had no previous experience. We call that hubris or DK. Watch his Oshkosh presentation way back on YT, it was all wishful thinking by someone with stars in his eyes at best or complete nonsense to those who've been there before him on similar projects.

I've admired his tenacity and yes, he is flying Raptor and that is quite an accomplishment but it falls FAR short of meeting his lofty projections or even being a practical airplane as it sits. It weighs TWICE as much as his original projection back in 2013. This isn't a one-off for personal use, it was designed to be a production kit for the masses- huge difference there.

It won't come anywhere close to the performance of a 20 year old Lancair IV-P in any area- speed, ROC, TO distance, useful load, ceiling, fuel burn or range. The IV-P was the existing benchmark to beat.

He's spent over 2 million dollars, 8 years and at least 20,000 man hours getting to this point. Most of us here don't find that too impressive given the demonstrated performance to date- hardly the world beating performance he was promising many years ago.

Yes, he and a big team of people got it built and that may be enough to claim victory for some folks but the fact is it's a one person aircraft with 15 gallons of fuel aboard.

This design has a very long ways to go (and a second prototype) before it may prove itself to be worthy of production.
 
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