10/23 Raptor Video

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Rataplan

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Oh yeah. I've long lusted after Rutan's M-309; compact, ~200 HP engines.
(Edit: Since I'm one of the old pharts who can remember this coming out of Rutan's barn, I remember it having IO-360's, yet anything I find online now says they were 550's. Anyone know?)
View attachment 109550
I'd prefer it to the Velocity. But Adams turned it into a bloated pig.

And, the Velocity is available... the M-309 is not.
Looks nice but not a canard, this one is a canard and push pull together :

 

galapoola

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An inline twin has it's advantages, engine redundancy of course. Managing an engine out or fly on one engine is not as dramatic. A canard plane doesn't need twin booms although the Double Ender and that WW2 German design don't either. Keeping the weight down has always been a trade off. Take an overweight Raptor and add an engine is going to be pig. Two smaller lighter 0-xxx's may weight less than the Audi package but it may not have enough HP to maintain altitude on one engine. All academic of course, he's committed to the diesel.
 

flywheel1935

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Here's a thought. I admit I know bugger all about VP props, but I'm guessing that the oil that controls the prop (the dirty engine oil) is being pumped by the same oil pump that's feeding the engine?. Would it be possible that cycling the prop would then result in fluctuations within the oil feed to the rest of the engine??? Also PM has still not confirmed that the oil system was flushed out totally after his previous engine failure.
 

PPLOnly

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Here's a thought. I admit I know bugger all about VP props, but I'm guessing that the oil that controls the prop (the dirty engine oil) is being pumped by the same oil pump that's feeding the engine?. Would it be possible that cycling the prop would then result in fluctuations within the oil feed to the rest of the engine??? Also PM has still not confirmed that the oil system was flushed out totally after his previous engine failure.
Potentially, yes and that should be something he is designing for. Normally the prop doesn't make big movements so it doesn't require a lot of oil to run. He also pretty much confirmed that he did not flush the oil system when he discussed the turbos. I don't think he thinks the oil was contaminated considering what he (didn't) find in the oil filter.
 

wsimpso1

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The prop governor is an engine driven pump with pressure regulation using oil normally fed to the crankshaft front main bearing. Oil pressure and flow to the prop is only adversely affected if oil flow to the front main bearing drops way off, like when the engine is out of oil.
 

5761RF

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I can hear the TV (that rattling sound is characteristic) almost everywhere around idle now and it still has the serious shakes at high rpm. Static error is just as bad as before.

I think he'll find the cooling issues will be much worse in the warmer weather.
A huge vibration and rattle occurs at 4:38 as the throttle is advanced for the high speed taxi, as if there's a transient cylinder dropout.
 
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Victor Bravo

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Am I the only one who watched the altitude go from 240 feet to 340 feet and then back to 240, all while the aircraft was rolling on the ground? Did I hear him say he put the static port on the belly of the airplane???? He has a flight test prototype without a pitot-static-alpha boom, or a Prandtl tube at the very least???
 

rv6ejguy

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Am I the only one who watched the altitude go from 240 feet to 340 feet and then back to 240, all while the aircraft was rolling on the ground?
No, we've been mentioning this ever since the first taxi tests and I just mentioned it again in post 2090 above. He's tried to "fix" it about 5 times now.
 

AdrianS

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No, we've been mentioning this ever since the first taxi tests and I just mentioned it again in post 2090 above. He's tried to "fix" it about 5 times now.
Maybe slightly off-topic, but a few years ago I helped a mate set up his turbocharged bike, which required a pressure line to feed boost back in to pressurise the carbs.

We tried about 5 variations of the pressure take off geometry before we came up with one that gave a linear response without over or under reading as the airflow increased.
Its not as simple as it looks at first glance.

Mind you, we spent a few fays on it, and got it right - and no-ones life depended on it. PM doesn't seem prepared to spend the time to get things right, for some reason.
 

Rataplan

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Maybe slightly off-topic, but a few years ago I helped a mate set up his turbocharged bike, which required a pressure line to feed boost back in to pressurise the carbs.

We tried about 5 variations of the pressure take off geometry before we came up with one that gave a linear response without over or under reading as the airflow increased.
Its not as simple as it looks at first glance.

Mind you, we spent a few fays on it, and got it right - and no-ones life depended on it. PM doesn't seem prepared to spend the time to get things right, for some reason.
No, we've been mentioning this ever since the first taxi tests and I just mentioned it again in post 2090 above. He's tried to "fix" it about 5 times now.
All his fixes are nice for a Holywood movie where the pilot has to make an emergency landing in the middle of nowhere and has to fix his plane with some old stuff he found in an old deserted petrol station, just to be able to hop his plane out of there .
 

mcrae0104

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Am I the only one who watched the altitude go from 240 feet to 340 feet and then back to 240, all while the aircraft was rolling on the ground? Did I hear him say he put the static port on the belly of the airplane???? He has a flight test prototype without a pitot-static-alpha boom, or a Prandtl tube at the very least???
It's really too bad nobody's ever figured out a way to deal with pitot-static issues during flight test...
 

Malish

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" Just when you thought it was safe to go back in the water (air)" >thank you Mr Spielberg<

On this video PM said that he had to replace cracked pulley and belts on reduction unit. Major oil leak, piston connecting rod brake, turbine malfunction and now cracked pulley - isn't to much for just few dozen hours running the power plant?
 

rv6ejguy

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On this video PM said that he had to replace cracked pulley and belts on reduction unit. Major oil leak, piston connecting rod brake, turbine malfunction and now cracked pulley - isn't to much for just few dozen hours running the power plant?
I think it was the accessory drive belt and pulley, not on the redrive. He said it was damaged and didn't notice it on installation.

However, the propulsion system hasn't been reliable at all, with the drive being stripped down and modified at least a dozen times in less than 50 hours of run time. I don't think anyone will be flying with this PSRU solution to Hawaii as PM envisioned...
 
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Aesquire

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A few dozen hours and some are astonished that list is so short. Starting with an untried new auto engine, and home designed PRSU & mounting, I'd expect you'd ( or I'd ) be still looking for the next week link to fail at a dozen flight hours.

And starting with a very advanced complex engine with supercharging? That's harder than a simple engine without modern complexity. Computerized fuel and ignition offer great timing and optimization potential, and while mechanically a fuel pump and a few squirters is "simpler" than a carburetor, you are trading software for jets, passages, bleeds, etc. And a more complex wiring harness and more sensors.

Then there's the packaging problems of Turbo supercharging. A look at the era of supercharged piston engined high performance craft, WW2, when supercharging determined the usefulness of a war plane depending on theater and role, shows only 2 turbo supercharged production fighters. There were a handfull, ( but built by the thousands ) of big bomber or recon planes with turbos, but just 2 single seaters.

One, the P-38, was a multi engine bleeding edge advanced design with big twin tail booms to put the turbos, intercoolers, oil & coolant radiators, etc.

The other, the P-47 was a design evolved to use the space that was formerly the passenger and cargo volume in a previous multi role design.

Heck, it's a packaging challenge to turbocharge a 74 Dodge Dart, in an engine bay unconstrained by aerodynamics.

So I'm aware of the difficulties. Especially with a ( insert German over engineering joke here )
 
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