Raptor Composite Aircraft

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Speedboat100

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I've made some sharp-tongued comments on this thread and joined others in questioning Peter's thought process. But one thing in that "first flight" video just broke my heart for the guy. He had completed a first flight on a brand new airplane, one with a lot of wonky stuff on it, managed to control the airplane even despite some obvious aero and/or elastic issues, and plenty of wonky engine issues. He did it pretty successfully, and he didn't scratch the airplane.... and there was nobody there to pat him on the back, hand him a beer, congratulate him, or be happy for him. That's really sad, as a separate issue from whatever is wrong with his airplane or wrong with him as an airplane builder.

I agree...he ought to have been celebrated. He survived what many would have not.
 

AdrianS

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Australia
So here's my thoughts on how a project like this should have been done.
This is not to bag PM, and bearing in mind I've never designed, built, or flown an aeroplane, but have done lots of other r&d heavy projects.
It's more an exercise in how to approach a task like this.
I'm ignoring the original design process, just looking at what follows.
Feel free to point out where I'm wrong, and I'll blame the post-op sedation ;).

1. Separate the engine testing from the airframe.

1a. Once the Audi was chosen, start building and testing the engine / PSRU in parallel to the airframe.
Obviously you can't test altitude performance, but it could easily have had 50-100 hrs running at cruise load by the time the airframe was ready. This would include a jury-rigged air induction mock-up, with a mains powered fan to provide airflow to the rads.
1b. Weigh the completed drivetrain, fluids and all.

2. KISS - it's a prototype.
2a. Forget pressurisation for the first flight model. By all means design for it, but don't bother building or installing it until the bird has flown.
2b. Fit a minimum functional interior - no cupholders, leather seats, or interior panelling. Just safe seats, harnesses, instruments, and flight controls.
2c. This probably includes fixed / locked-down landing gear.

3. Instrument the hell out of it. Sensors, cameras, and data recording is dirt cheap.

4. Have a test schedule. Each run, including taxi tests, should have a clear set of objectives - why you are doing this run, and what you hope to test / verify by doing it.
Clearly set targets to be met before proceeding to the next testing step.

I am sure I've got some of this wrong, so please point it out.

As I said, this isn't an attack on PM or Raptor, or an exercise in "I told you so", but an attempt to clarify how to approach a project like this with a limited budget and limited manhours.
 

IO390

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So here's my thoughts on how a project like this should have been done.
This is not to bag PM, and bearing in mind I've never designed, built, or flown an aeroplane, but have done lots of other r&d heavy projects.
It's more an exercise in how to approach a task like this.
I'm ignoring the original design process, just looking at what follows.
Feel free to point out where I'm wrong, and I'll blame the post-op sedation ;).
Where would you fit in the note about pulling performance and price figures from thin air?
 

Speedboat100

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I was very skeptical from the beginning myself. However I know how the escrow.com works. It is virtually impossible to loose your money in it. In details: The Raptor team does not have my money. Until they would deliver my order. The money is stored on escrow account. The fast delivery is in their business' interest to deliver the product soon - to get their pay back - and that explains a lot. That is why we (users-clients community) have our updates twice a week - and monitoring team's progress from the beauty and comfort of our office. Those folks are working hard - weekends and late nights are recorded daily. So - I am not advocating them - simply saying it is not any close to what we do when "Vaporware" is being created.:tired:

Have they informed you the date when you can pic your 130 000 usd miracle ship ?
 

berridos

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1,130
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madrid
The location of the canard on top of the fuselage nose, above the widest lateral nose section, is an aeordynamic nightmare. Basically Arnold stated that at least the angle to the fuse should be 90º or more. At that location he has significantly less than 90º and that feature is much more relevant than the area rule. He should have placed the canard right at the nose like a hammer shark to fly in clean air and have less intereference drag. Guess that costs him a bunch of knots and turbulence that makes the canard have less control authority.
 

AdrianS

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Messages
599
Location
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Where would you fit in the note about pulling performance and price figures from thin air.
I'm trying to make this a learning exercise (for me at least), not a slanging match.

That said, you need to have some design goals. On the engine side, it's pretty straightforward : your design has a target power, weight, and fuel flow, as well as packaging constraints.

These can all be validated by bench (hanger) testing, without an aircraft. You don't even need an engine dyno, just a set of test clubs.
If it's clear your drivetrains isn't going to meet the design specs, you can :

a) Decide to live with the reduced performance and/or efficiency.
or
b) Re-evaluate your engine design.
or
c) Fall-back to an off the shelf alternative so flight testing can commence.
 

TarDevil

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Jun 29, 2010
Messages
846
Location
Coastal North Carolina/USA
So here's my thoughts on how a project like this should have been done.
This is not to bag PM, and bearing in mind I've never designed, built, or flown an aeroplane, but have done lots of other r&d heavy projects.
It's more an exercise in how to approach a task like this.
I'm ignoring the original design process, just looking at what follows.
Feel free to point out where I'm wrong, and I'll blame the post-op sedation ;).

1. Separate the engine testing from the airframe.

1a. Once the Audi was chosen, start building and testing the engine / PSRU in parallel to the airframe.
Obviously you can't test altitude performance, but it could easily have had 50-100 hrs running at cruise load by the time the airframe was ready. This would include a jury-rigged air induction mock-up, with a mains powered fan to provide airflow to the rads.
1b. Weigh the completed drivetrain, fluids and all.

2. KISS - it's a prototype.
2a. Forget pressurisation for the first flight model. By all means design for it, but don't bother building or installing it until the bird has flown.
2b. Fit a minimum functional interior - no cupholders, leather seats, or interior panelling. Just safe seats, harnesses, instruments, and flight controls.
2c. This probably includes fixed / locked-down landing gear.

3. Instrument the hell out of it. Sensors, cameras, and data recording is dirt cheap.

4. Have a test schedule. Each run, including taxi tests, should have a clear set of objectives - why you are doing this run, and what you hope to test / verify by doing it.
Clearly set targets to be met before proceeding to the next testing step.

I am sure I've got some of this wrong, so please point it out.

As I said, this isn't an attack on PM or Raptor, or an exercise in "I told you so", but an attempt to clarify how to approach a project like this with a limited budget and limited manhours.
Yep. Start over.
Any additional dollars and sweat invested in the current airframe are waste. Fruitless to prioritize what needs to be done to Raptor V.1.
But yes, use the lessons learned for V.2, if the concept is valid.
 

Wild Bill

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Dec 11, 2013
Messages
104
Location
Vidalia, GA
You can turn off image stabilization but then you potentially end up with a blurry, vibrating image.
It looks like by now, some sort of vibration damper mount would be a standard included item with action cams.
We used to make our own for vehicles. They were a pain, and bulky, but a must have. No jelly effect and a fixed camera perspective.
 

rv6ejguy

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Jun 26, 2012
Messages
4,153
Location
Calgary, Alberta, Canada
I'm trying to make this a learning exercise (for me at least), not a slanging match.

That said, you need to have some design goals. On the engine side, it's pretty straightforward : your design has a target power, weight, and fuel flow, as well as packaging constraints.

These can all be validated by bench (hanger) testing, without an aircraft. You don't even need an engine dyno, just a set of test clubs.
If it's clear your drivetrains isn't going to meet the design specs, you can :

a) Decide to live with the reduced performance and/or efficiency.
or
b) Re-evaluate your engine design.
or
c) Fall-back to an off the shelf alternative so flight testing can commence.
While you might be able to find some weakness with simple club testing, proper engine development PSRU development/ validation programs would require MANY hundreds of hours running anywhere from idle to full power (for hours, not minutes) with instrumentation on the PSRU to map torsional vibration characteristics across the whole operational range of RPM and MAP to know if anything dangerous is lurking. You need an engine and vibe guy IMO to do a proper job here to have confidence to be able to sell said package to the public on a big scale.

As a minimum, Peter needed to consult (and listen to) people learned in the fields of diesel engines, turbocharging, cooling, diesel engine management and PSRU design to have any chance of success here. He didn't and look where he is now. His hubris was frankly mind boggling. His online courses in diesel engine mapping and turbocharging were obviously no substitute for years of actual expeience in these fields. Every part of this propulsion system is a ticking time bomb.

Frankly, Peter is incapable of developing this engine package to safely power Raptor. Choice C. is the only way he could proceed IMO.
 

rbarnes

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Joined
Aug 28, 2015
Messages
391
Location
Texas
11...

Ugh. The list just goes on, doesn't it? Even with all that there's still an s-ton of unknowns and outstanding issues to be resolved. What a daunting mountain he's gonna have to climb... all the more so because he's been trying to dig his way under it for the last 3-4 years. But, for my own gratification, would that seem like an appropriate plan to move forward given the current situation, if one was bound and determined to make Raptor work? I feel like.... this prototype as it stands will only ever be useful to validate the drivetrain and the overall aerodynamics, I don't think it would make any sense at all to invest in trying to validate or troubleshoot its structural or inherent weight problems... those I feel would be best addressed starting from scratch with the layups originally recommended and then incrementally moving forward from there. Which could be done in parallel with the work on this prototype, to keep the momentum going. All it takes is money, right? ;)
You left out the kludge that is the entire flight control system is well.
 

IO390

Member
Joined
Aug 11, 2020
Messages
11
I'm trying to make this a learning exercise (for me at least), not a slanging match.

That said, you need to have some design goals. On the engine side, it's pretty straightforward : your design has a target power, weight, and fuel flow, as well as packaging constraints.

These can all be validated by bench (hanger) testing, without an aircraft. You don't even need an engine dyno, just a set of test clubs.
If it's clear your drivetrains isn't going to meet the design specs, you can :

a) Decide to live with the reduced performance and/or efficiency.
or
b) Re-evaluate your engine design.
or
c) Fall-back to an off the shelf alternative so flight testing can commence.
Yes, it's good to see where this has gone wrong. I've asked the same question myself.

This project hasn't been planned or managed in any meaningful way. It's one thing to get your prototype finished and then make some kludges to fix issues that are then fixed in prototype #2... However, Peter is so far down this route that the entire plane is made of TLAR type botches just so he can get to the next stage. I don't see how any of this is salvageable without going right back to step 1.

So the only real lesson here is don't embark on a hugely complicated project without doing your due diligence. I don't think there is anything else to learn. We're not talking one or two screwups here.
 

wwkiefer

Member
Joined
Aug 27, 2014
Messages
12
Location
kalamazoo, michigan
Why only low pressure?
Yeah, maybe the Raptor isn't suitably complex and poorly engineered enough already.
Low-Pressure <250 PSI, uses lighter, less stressed components, it's easier to install, service, and reliable.
I would submit the cable pulley system installed, re-engineered, modified, and then jerry-rigged is a cluster of epic scale; If the engine does not fail in flight, it will be a control system failure, that brings the bird down. IMHO
 

pictsidhe

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Joined
Jul 15, 2014
Messages
8,812
Location
North Carolina
If he had a reliable powerplant, and I realize that he doesn’t, there are aero lessons to be learned about the basic configuration.


BJC
Just knowing the hp would useful.
He has rebuffed everyone who has advised him to make a power measurement. Even the quick and dirty one from me suggesting he put his scales under the mains and measure the torque on the airframe. Apparently, that would just be a number and of no use to the project.
Meanwhile, he seems perplexed as to why his 400hp aircraft is performing so sluggishly. This can't just be ego, can it? Surely there must be BS involved.
Without sufficient power, this thing will have dreadful numbers such as takeoff distance, climb rate, speed, altitude. People will buy or pass depending on those. Oh, look, it does have dismal numbers. Must be because the gear is still down!

I came up with some ideas to give it more power and cooling back here. Yes, they are horrific kludges, but they would work. They are simple, would help the engine significantly AND fit into his "no major issues" story.

Like it or not, Peter is going to try kludging this. Suggesting he fix the Audi by relocating it to a dumpster is not going to get entertained. At some point, something will break. If he has more altitude, it's much more likely to end well.
 
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