Raptor Composite Aircraft

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Turd Ferguson

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Mar 13, 2008
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How about if we compare SpaceX with Soyuz today - same story - twenty years ago it was ridiculous, two years ago it could not be possible - today is a reality and exactly the same unproven design : airframe engine etc etc
That comparison is not even close. That would be like comparing the kid building a wooden push car in his back yard to General Motors. However, the 20 yr timeline from conception to first flight may turn out to be comparable....

When somebody burst onto the scene claiming they can revolutionize light personal airplanes and travel, a healthy does of skepticism should be the rule.
 

anvegger

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Jul 6, 2015
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LACONIA NH USA
Only because I know how the work of Diamond Aircraft on converting Austro Diesel has been done - and now Thanks to Peter we have our very home built version of it

 

flywheel1935

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Nov 1, 2018
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Downham Market, Norfolk, UK.
Just watched the 'latest' YT vid, is it me, but at about 12.02 to about 12.22 the 'structure' thats operating the elevator far right on screen, seems to 'kick' as Peter moves the stick for and aft. looks like a short rosejointed element that bolts to the sidestick up near the aileron bell crank, but the outer tube seems bigger than the inner tube and is 'rocking'. Also posed the question regarding the control system issue on Elliots YT vid, and got a personal reply that indicated Peter was aware of said issue but ignored it first time around, "The Future of General Aviation" jurys still out ?????
 

pictsidhe

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Jul 15, 2014
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We've discussed his stick assembly here. It wasn't liked... I'm stunned that he hadn't properly tested it himself until it was flagged. Who doesn't test their stuff?
He is finding out that engineering something by suck it and see rather than by calculation or experience is slow, expensive and incredibly frustrating. Building stuff so you can access it later makes life so much simpler in the long run.
That stick bearing has way too much clearance on the shaft, it is getting edge loaded.
 

UAVGuy

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May 1, 2020
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18
I did however,through the test model exercise, take a design that would not fly( initially not at all) well and corrected many aero problems to enable it to fly pretty well. But again, I say, I was only able to put 3-4 flights on the model.
You built and flew the 1/4 scale model for Peter ?

I have a question about the final weight. There seemed to be a lot of CAD and design done and yet the final weight was way higher than anticipated. How did that happen ? Were the composite pieced heavier than planned ? Were allowances not made for component weights ? Were pieces weighed as they were made and compared to the design or was everything weighed at the end and the total was found to be a surprise ?

I'm trying to learn vicariously and don't wish to repeat his experience.

I have another question... what tools were used to select the appropriate composite thickness and layers ?
 

rbarnes

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Aug 28, 2015
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Texas
There seemed to be a lot of CAD and design done and yet the final weight was way higher than anticipated. How did that happen ?
Peter said he never calculated the weight (nothing was ever calculated on the plane) and that the estimated weight was just a guess (complete fabrication from imagination) based on the weight of the SR22.
 

Scheny

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Feb 26, 2019
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Vienna, Austria
I just checked the repair manual for the SR22. It is using 7781-F16 fibers from Hexcell with ~9oz weight. Except for edges (where up to 10 layers without a core are used), the base layup are 2 layers (~18oz) per side on a 0.375 (or less) foam core.

As it is glass fibre, you would even need less in carbon. My guess is, that 12oz per side should already do the trick.

In one of the videos you can see that Peter is using roughly 48oz per side on the keel if I remember correctly. As this is not subjected to pressure, I would consider it overdimensioned by a factor of 4! Not even the stepping area on the wing of the SR22 is using that much fabric. This would explain the weight.

I am just curious how he came to the conclusion on how much carbon is required.
 

wsimpso1

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I just checked the repair manual for the SR22. It is using 7781-F16 fibers from Hexcell with ~9oz weight. Except for edges (where up to 10 layers without a core are used), the base layup are 2 layers (~18oz) per side on a 0.375 (or less) foam core.

As it is glass fibre, you would even need less in carbon. My guess is, that 12oz per side should already do the trick.

In one of the videos you can see that Peter is using roughly 48oz per side on the keel if I remember correctly. As this is not subjected to pressure, I would consider it overdimensioned by a factor of 4! Not even the stepping area on the wing of the SR22 is using that much fabric. This would explain the weight.

I am just curious how he came to the conclusion on how much carbon is required.
The composite skin for the Cirrus is then similar to what is used on Long-EZ's, Cozy's, and the like, where it is put on over cores of tan PU and blue PS foams. Vacuum bagging it on over PVC foams makes it sturdier still. Understand that all of this is way overbuilt for flight and landing loads, and is sized mostly to stand things like build bumps and bangs, starling strikes, and worst of all, Airshow Morons.

When you go to graphite fiber 12 oz on each side of foam cores is another increment sturdier. As I understand it, SpaceShipOne was similar and it was pressurized as a double hull vessel.

That the Raptor is much beefier than that is apparent in almost every view of the airframe we have gotten. The lack of any kind of weight tracking and design of control systems for stiffness under control run loads is disappointing.

Billski
 

pictsidhe

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Very little of the Raptor design was calculated. Almost none by Peter it seems. He had some critical parts such as spars checked by someone else, while skipping over 'trivial' things like the controls. Guesswork was the main design method. That isn't good for weight, performance, or safety. If the Raptor ever moves towards production, somebody needs to go through the entire design with a calculator and red pen. A one day check such as by Mark can only scratch the surface.
 

galapoola

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Jun 4, 2017
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69
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NJ
Looking back when I first began following this project, I absolutely recall thinking, "this guy has bitten off way more than he can chew". Admiditally he's identified and resolved much but the enormity of systems . . . Hopefully he can get this in the air safely once for closure and move on. The cash flow will probably take care of this all by itself.
 

MolsonB

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Nov 12, 2014
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Ontario, Canada
I'm not sure I can put in words what I'm thinking, but to me I find this more interesting from a human study point of view on success. Following this and the Dark Aero build, (not comparing the planes, or what they are claiming performance numbers to be, just how they run their project / business).

Dark Areo = You have 3 engineers who listen and bounce ideas off each other (they are brothers, they have to work well together). They are using their own money, and interact with public input. In my experience, when you build something using your money vs money given to you. You'll be a lot smarter when using your money with the choices / paths you take.

Raptor = It started off strong (the project, not the performance numbers of the plane). I was rooting for them. Being all digital and having Jeff's experience. But as the years went on, you can see from the videos that Peter's ego killed the success. The I'm smarter then you, just doesn't work. At this, or in life.

I think to be successful in life, you need to check your ego at the door and admit you can't do everything. It's okay. It's okay to ask for help, it's okay to learn from others. It's even okay to work with others. One of my first bosses told me, 'Always surround yourself with people smarter then you, instead of trying to be the smartest person in the room'. I think ego has killed many many many pilots.
 

TarDevil

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Jun 29, 2010
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Coastal North Carolina/USA
I'm not sure I can put in words what I'm thinking, but to me I find this more interesting from a human study point of view on success. Following this and the Dark Aero build, (not comparing the planes, or what they are claiming performance numbers to be, just how they run their project / business).

Dark Areo = You have 3 engineers who listen and bounce ideas off each other (they are brothers, they have to work well together). They are using their own money, and interact with public input. In my experience, when you build something using your money vs money given to you. You'll be a lot smarter when using your money with the choices / paths you take.

Raptor = It started off strong (the project, not the performance numbers of the plane). I was rooting for them. Being all digital and having Jeff's experience. But as the years went on, you can see from the videos that Peter's ego killed the success. The I'm smarter then you, just doesn't work. At this, or in life.

I think to be successful in life, you need to check your ego at the door and admit you can't do everything. It's okay. It's okay to ask for help, it's okay to learn from others. It's even okay to work with others. One of my first bosses told me, 'Always surround yourself with people smarter then you, instead of trying to be the smartest person in the room'. I think ego has killed many many many pilots.
One can only hope Peter lurks this forum and reads this. At this point in his project, it may ring true. His vision MIGHT be saved if he gets production funding to build again with the advice and input of qualified individuals.

Then... he'll have an airplane similar to Velocity. Hmmm....
 

David Lewis

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Oct 4, 2018
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Location
Longwood FL
The Raptor will weigh about 3200 pounds ready to fly. The model was 1/4 scale. It would have to weigh 50 pounds in order to be a valid representation of the real plane.
The model I built was quarter scale at 8 foot span, give or take, and weigh approx 30 pounds.
The 50 pound weight UAVGuy calculated would keep cube loading the same.
Accounting for Reynolds number is another, separate concern.
 

anvegger

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Jul 6, 2015
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LACONIA NH USA
You must not be reading the thread closely; Kerlo literally just posted his project status eight posts prior to yours.
I do respect Jeff's work more than anyone else (see my research of Jeff's projects few years back) but I have to admit that keeping low profile does not do any good for the best project ever. We are living in a new world and amount of money and comments from hundreds of people supporting Raptor - that is the proof of open minded transparency that makes a lot of exposure that leads to sharing money, resources, knowledge and progress overall . $10 000 a day cannot be donated at all by stupid incompetent people only Read the comments from the audience

 
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