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Just shove a Jeep 4.0 inline six in it. It's almost impossible to kill those.
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Oct 14, 2020 07:21
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| # ? Jun 3, 2024 21:21 |
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 When you’re a strong, independent plane who don’t need no pilot.
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Oct 14, 2020 08:21
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I think he used the Audi V6 diesel motor because it’s relatively cheap, light, efficient, and powerful. Being a software guy/disruptor, the risks of using such a power plant with no redundancy well outside of its intended power range for extended periods of time are lost on him. I really like the big fuckoff timing belt reduction as well. Especially the fact that the engine is soft mounted but the hub is not, so engine movements change belt tension and vise versa.  Just to clarify, I like the idea of the plane and I like the fact that it is something relatively novel and entrepreneurial. Seeing it come together is cool to watch on some level. But he is doing it with other people’s money and outright refusing to take good advice or learn from his mistakes. If it were just some whacko building it in his shed it might be cute but as is he is not only putting himself and others at risk, it’s a tremendous waste of resources that is frustrating to see.
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Oct 14, 2020 13:49
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Imagine the crankwalk resulting from a propeller hanging off the crank flange.
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Oct 14, 2020 14:02
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Isn't that essentially what you have in nearly every piston aero engine though? Or is there some kind of big extra bearing that supports the prop assembly?
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Oct 15, 2020 05:18
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I've always been told that a normal Lycoming / Continental has big bearings, as well as that chunky prop flange. You've typically got a 76" long 37lb chunk of metal bolted to the end of the crank, and it's getting gyroscopic forces put into it as you move from climbing to descending. The prop can't spin much over ~2700rpm, which means most auto engines need to be geared down in order to make full power. PSRUs (prop speed reduction units) are supposed to handle both reducing the output RPM to something manageable, and to handle the forces from slinging a big chunk of metal around, but auto-engine conversion PSRUs don't have a great record in aviation. In bigger piston engines, gearboxes were at one point common (no big piston engines are common these days), but the reduction gear driven smaller aircraft engines also have a reputation for being finicky. They've got a better reputation then auto-conversions, but worse then a prop bolted to a crank.
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Oct 15, 2020 13:18
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Sagebrush posted:Isn't that essentially what you have in nearly every piston aero engine though? I forgot to check down thread before I replied. I was specifically chuckling at the idea of a 4G63T or something, which is an engine family known for having lovely longitudinal crank retention even in automotive applications. Lycoming flat engines as an example, have a thrust bearing on the inside of the case around the crank flange.
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Oct 15, 2020 13:29
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I assume the dude picked the Audi diesel because the reduction gearing ratios are less since peak power is a lot closer to the appropriate RPM range for a prop than say, a 13B. But just, fuckin lol at picking that engine of all things.
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Oct 15, 2020 14:44
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KYOON GRIFFEY JR posted:I assume the dude picked the Audi diesel because the reduction gearing ratios are less since peak power is a lot closer to the appropriate RPM range for a prop than say, a 13B. But just, fuckin lol at picking that engine of all things. I assume it's because it says Audi on it instead of some no-name brand like Lycoming.
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Oct 15, 2020 14:54
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Oddballs: C-133
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Oct 15, 2020 15:02
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The typical alternative engine application starts by someone being mad at a maintenance bill. Why does it cost so much, why only a few hundred hours between service intervals when my car goes on forever, old technology etc. It will cheaper maintenance, easier operation and lower fuel consumption to use an automotive. Oops turns out it's really complicated. The Eggenfellner Subaru installations which caused the RV-10 crash linked earlier promised to be cheaper, lighter and more economical but turned out to be more expensive, heavier and used more fuel.
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Oct 15, 2020 15:34
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Yeah, when my dad did the overhaul on his I couldn't believe how expensive it was compared to a car engine. But it's the price you pay to have an engine that is made for a specific use where a failure doesn't mean pull over and stop. You life is on the line when you're in the air. It's worth the cost.
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Oct 15, 2020 15:44
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Does anyone doubt that the engines used in general aviation today could be substantially improved with R&D? It’s just not going to happen with a bloke working in his garage on the weekend.
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Oct 15, 2020 15:47
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I'm positive that engineers today could take the power, weight and packaging figures of the O-235 or whatever and come up with something new that improves on all three areas while keeping the same reliability. The problem is in demonstrating that you've succeeded in doing so. All the engineering and testing in the world can't replace fifty years and millions of hours of actual demonstrated reliability, and all the associated opportunities to find and address every single tiny remaining problem. Proof counts for a whole lot more than theory when life is on the line.
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Oct 15, 2020 16:19
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https://twitter.com/AvatarDomy/status/1316365983926423552
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Oct 15, 2020 16:33
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He really buttered the bread on that landing.
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Oct 15, 2020 16:40
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I hate hearing that particular turn of phrase to describe a landing but yeah. Putting all those Alaska STOL pilots to shame. I sometimes wonder what it must be like to be a bird and have an intuitive, automatic sense of all these aerodynamic phenomena that we apply in aviation. Like I was down at the beach and saw a flock of pelicans skimming 6 inches above the water for hundreds of yards, and I realized that they were in ground effect, and they probably just feel that the flying gets easier when they're that close and were doing it intentionally. Or if you watch a bird hovering in place in a strong breeze for a while, you'll see them constantly making tiny pitching motions to adjust their airspeed as the wind gusts up and down, just like an airplane descending on final. When birds spread their wingtip feathers for landing and they splay out a bit, they behave exactly like leading-edge slats and it reduces their stalling speed, but the bird probably just feels it like they can "grab" the air better or something and they just do it. I wish I was a bird. Sagebrush fucked around with this message at 17:19 on Oct 15, 2020 |
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Oct 15, 2020 16:48
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"You guys alive? Hm, I see, are you sick? Any chance you might fall soon? No? Well I'm out"
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Oct 15, 2020 16:50
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Sagebrush posted:I hate hearing that particular turn of phrase to describe a landing but yeah. Putting all those Alaska STOL pilots to shame. At this point, human interface with transportation devices requires us to adapt our sense of balance, force, and control inputs to the device, and our brains learn how to operate them to the point where most operations are nearly autonomous. The interface reamins a bit clunky. I am hoping that DARPA or some similar is working on an aircraft that brings these inputs to the almost-synthetic, with operation icontrolled by human inputs almost automatically, with feedback systems that allow a human body to sense its orientation in all three axes, to the point that operation becomes second nature once the cues bed in to your brain.
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Oct 15, 2020 17:00
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Sagebrush posted:I hate hearing that particular turn of phrase to describe a landing but yeah. Putting all those Alaska STOL pilots to shame. All that is neat and stuff, but imagine being able to feel with your toes how close you are to the ground or how hard this landing is about to be and have a reflexive feedback mechanism in place to adjust control surfaces to smooth all that out.
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Oct 15, 2020 17:09
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I wonder if birds have a better inner ear than we do and it auto corrects back to horizontal unlike ours.
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Oct 15, 2020 17:10
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Cojawfee posted:I wonder if birds have a better inner ear than we do and it auto corrects back to horizontal unlike ours. Migratory birds also have a pretty decent built in magnetic compass too. If its sophisticated enough their brain could be using that along with their inner ear potentially giving them a "6 axis" accelerometer.
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Oct 15, 2020 17:14
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Sagebrush posted:I'm positive that engineers today could take the power, weight and packaging figures of the O-235 or whatever and come up with something new that improves on all three areas while keeping the same reliability. Yeah, it reminds me of a video about a team that restored and flies some WWI aircraft. After talking about specific parts they have to replace after every 3 flights or something the interviewer asked why they don't just engineer a better version of that part with modern technology/materials instead of using the original specs. The engineer basically tells them "because we have 100+ years of history telling us exactly what will break and when. If we fix that part to work better suddenly the engine is being put under new stresses it's never seen before and we have no idea what that will mean or where the next failure will be."
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Oct 15, 2020 17:16
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You know what, birds probably just rotate their head so they always feel a downward force so it probably doesn't affect them.
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Oct 15, 2020 17:19
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Cojawfee posted:You know what, birds probably just rotate their head so they always feel a downward force so it probably doesn't affect them. Do birds fly "coordinated"?
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Oct 15, 2020 17:21
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babyeatingpsychopath posted:All that is neat and stuff, but imagine being able to feel with your toes how close you are to the ground or how hard this landing is about to be and have a reflexive feedback mechanism in place to adjust control surfaces to smooth all that out. Well sure. If you're a bird I'm sure that you can not only feel when you're in ground effect, but you know exactly how close you are and what your sink rate is by the magnitude of the effect, and you just automatically move your wings and tail to make a perfect tiptoe touchdown every single time. https://www.youtube.com/watch?v=pnD64lCIc90 Cojawfee posted:I wonder if birds have a better inner ear than we do and it auto corrects back to horizontal unlike ours. Well, human inner ears also auto correct back to horizontal -- we just need visual references to do it. I wonder if birds get the leans when they fly through a cloud. Do birds even fly through clouds? Sagebrush fucked around with this message at 17:32 on Oct 15, 2020 |
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Oct 15, 2020 17:27
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Sagebrush posted:Well sure. If you're a bird I'm sure that you can not only feel when you're in ground effect, but you know exactly how close you are and what your sink rate is by the magnitude of the effect, and you just automatically move your wings and tail to make a perfect tiptoe touchdown every single time. I don’t know if birds’ vestibular system can balance without vision but iirc their sense of gravity is sensitive enough for them to right without seeing
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Oct 15, 2020 17:46
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Sagebrush posted:I hate hearing that particular turn of phrase to describe a landing but yeah. Putting all those Alaska STOL pilots to shame. Pro: when you have feathers, you get tactile feedback of what the air is doing. con: when feathers get ruffled they itch, and every bird spends an hour or two a day preening (IE fixing their feathers so they don't itch.)
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Oct 15, 2020 17:49
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hobbesmaster posted:Do birds fly "coordinated"? When I first saw Canada geese flying in perfect V formation I understood where formation flying came from.
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Oct 15, 2020 17:52
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I meant the slide slip definition
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Oct 15, 2020 17:58
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Nebakenezzer posted:When I first saw Canada geese flying in perfect V formation I understood where formation flying came from. My favorite autobiography from WW2 is "Serenade to the Big Bird", written by Bert Stiles. He was a B-17 co-pilot in '44, and before that he had a lot of buzz about being the next Steinbeck. Unfortunately, after his B-17 tour he volenteered for fighters, and crashed his P-51 following a german fighter into the ground... Anyway, here is his take on flying formation vs geese: "I read an article in a magazine once containing this fragment: . . in this highly organized air war over Germany,where the heavy American bombers plug along in rigid formation like militarized geese . . ." That is very nice, but the guy who wrote it is weak in the mind when it comes to heavy bombers and their formations.The word "rigid" just doesn't fit anything in the sky. The sky is fluid, and a formation is fluid. The strange thing is, from any distance, a formation is always static, and always beautiful. You don't hear the pilots screaming at the co-pilots and the element leaders bitching at the squadron leaders. "Get us out of here," somebody will call up the lead ship."Were in prop wash." "Can you cut it down a little?" "Can you pick it up a little? We're stalling out back here."Bitch, bitch, bitch. The Group leaders plead with the Wing leaders, and the Wing leaders weave in and out to stay in Division Formation,and the whole 8th Air Force gets there some way. A ground-gripper would never notice a low squadron over-running a lead squadron, or see the high squadron leader chop his throttles and almost pile his wing men into his trailing edges. From the ground, or to a passenger in the air, it just looks deadly and simple and easy. And actually it is deadly if it's flown tight, and the bomb pattern is compact, and it is simple and easy if you stay on the ball and fly. You can stay in some positions with two throttles,setting the inboard engines at a constant RPM, and moving the outboards a quarter of an inch at a time. You can fly back on the tail end of an 18-ship formation and spend the whole day sliding up on your element leader, punching rudders to keep from overrunning him, and pouring it on to catch up again. A formation depends on its leaders. Good squadron leaders and good element leaders make formation flying easy. Bad ones make it hell. From the day you start out in B-17s they tell you that formation flying is the secret of coming back every time. The Luftwaffe is always looking for a mangy outfit that is strung out halfway across Germany. When the Luftwaffe lies low for a few days, the formations begin to loosen up and string out and take it easy, then oneday the 190s come moaning down out of the clouds and the whole low squadron blows up and the high squadron piles into the lead squadron, and three or four ships out of a whole group come home. After that some pretty fair formation is flown for a while. It is always work, and nine hours of it on a Berlin trip knocks you flat, and if you have to drag out of the sack at two in the morning for another nine hours of the same thing,you feel like going over the hill with no forwarding address."
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Oct 15, 2020 18:02
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I think I read somewhere that owls ears are at different heights so they can tell how far up/down prey is along with where it is left/right. Not that it helps with flying so much but it’s cool. Also their eyes are fixed within their heads so they have to move their heads around instead of swivelling their eyes in the socket.
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Oct 15, 2020 18:04
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A lot of birds are like that. In turn, their brains developed very advanced stabilization. They walk around with their heads bobbing because they need to keep their head in one place to keep their vision stable. They walk forward and slowly move their head back until they can't and then they dart their head forward and do it all over again.
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Oct 15, 2020 18:18
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hobbesmaster posted:I meant the slide slip definition I'm sure birds do fly coordinated, again automatically just by adjusting their body until they feel the least drag. priznat posted:Also their eyes are fixed within their heads so they have to move their heads around instead of swivelling their eyes in the socket. Predator bird eyes are incredibly sophisticated. Hawks and eagles have visual resolution like 5 times better than the average human, due partially to a special extra layer in the back of their eye that somehow keeps the retina nourished without blood vessels running across it. They also can change the shape of their lens in real time to focus on their target and compensate for atmospheric distortion and water refraction, letting them see through heat haze and grab fish accurately from underwater. And they have the sliding translucent nicitating membrane that covers their eye for protection from triple-digit winds in a dive while letting them still see the target. Aeronautical Insanity: also birds are pretty insane when you think about it
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Oct 15, 2020 18:22
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Some aeronautical insanity for your afternoon https://www.youtube.com/watch?v=i-AZRtI366w
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Oct 15, 2020 19:07
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winnydpu posted:My favorite autobiography from WW2 is "Serenade to the Big Bird", written by Bert Stiles. He was a B-17 co-pilot in '44, and before that he had a lot of buzz about being the next Steinbeck. Unfortunately, after his B-17 tour he volenteered for fighters, and crashed his P-51 following a german fighter into the ground... That's great, thanks.
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Oct 15, 2020 19:28
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It reminds me: before the Guinness book of world records went to poo poo, they listed the highest flying bird observed, which was either seen or ran into by an airliner over sub-saharan Africa. It was a vulture, and the altitude was 30,000 ft
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Oct 15, 2020 21:30
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Cojawfee posted:A lot of birds are like that. In turn, their brains developed very advanced stabilization. https://twitter.com/kbiegel/status/1223125002414784512?s=20
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Oct 15, 2020 21:38
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Jetpack Guy spotted again near LAX at around 6000 feet https://www.cnn.com/2020/10/14/us/jetpack-guy-back-lax-trnd/index.html My fervent hope is that he's spending his time on the ground decking Nazis, because he really is The Rocketeer
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Oct 15, 2020 21:47
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There is no way jetpack guy is actually a guy in a jetpack. That of course leads to the question of what they're actually seeing. Wingsuit maybe? It doesn't quite fit though.
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Oct 15, 2020 21:51
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