Home |
Search |
Today's Posts |
|
UK diy (uk.d-i-y) For the discussion of all topics related to diy (do-it-yourself) in the UK. All levels of experience and proficency are welcome to join in to ask questions or offer solutions. |
Reply |
|
|
LinkBack | Thread Tools | Display Modes |
#41
Posted to uk.d-i-y
|
|||
|
|||
The mechanical bettery
On 24/08/2020 11:10, N_Cook wrote:
snip Wasn't there a totally above the rail (no counterweights below) gyro-stabilised monorail system somewhere, Ireland ISTR? There was a 'Lartigue' monorail which was effectively a train straddling a raised rail as if it were a wall, but no gyro one that I'm aware of. There was talk a few years ago among some local enthusiasts of building a Brennan monorail in or near Castlebar Co. Mayo where Brennan was born. I don't know where that got to, I'm guessing it didn't make it past the talking stage. -- Cheers Clive |
#42
Posted to uk.d-i-y
|
|||
|
|||
The mechanical bettery
williamwright wrote:
On 24/08/2020 10:59, Radio Man wrote: williamwright wrote: On 22/08/2020 17:27, harry wrote: https://www.youtube.com/watch?v=_QLEERYS5C8 No-one seems to know why flywheels store energy. Not really. Bill Angular momentum. That's just words. Bill I find it simplest to avoid the question of whether it *stores* energy and just accept that it can provide energy to a system that slows it down to the same speed and orientation as the rest of the planet. And, symmetrically, you can provide it with energy to start it spinning again. Whether it is stored or simply doesn't exist when you are not using it is a philosophical point, to which the philosophical answer is that energy is conserved in the system containing the flywheel. But that is just words, what matters is that you can put energy in and take energy out, the conservation of energy being a property of the system rather than of the flywheel. -- Roger Hayter |
#43
Posted to uk.d-i-y
|
|||
|
|||
The mechanical bettery
On 24/08/2020 13:11, Roger Hayter wrote:
williamwright wrote: On 24/08/2020 10:59, Radio Man wrote: williamwright wrote: On 22/08/2020 17:27, harry wrote: https://www.youtube.com/watch?v=_QLEERYS5C8 No-one seems to know why flywheels store energy. Not really. Bill Angular momentum. That's just words. Bill I find it simplest to avoid the question of whether it *stores* energy and just accept that it can provide energy to a system that slows it down to the same speed and orientation as the rest of the planet. And, symmetrically, you can provide it with energy to start it spinning again. Whether it is stored or simply doesn't exist when you are not using it is a philosophical point, to which the philosophical answer is that energy is conserved in the system containing the flywheel. But that is just words, what matters is that you can put energy in and take energy out, the conservation of energy being a property of the system rather than of the flywheel. or you can just accept that the energy is real and its existence is intrinsic to the mass-energy equivalence in relativity - a theory which has been tested by a wide range of experiments (and applies to rotational energy as to other forms) -- Robin reply-to address is (intended to be) valid |
#44
Posted to uk.d-i-y
|
|||
|
|||
The mechanical bettery
On 24/08/2020 10:59, Radio Man wrote:
williamwright wrote: On 22/08/2020 17:27, harry wrote: https://www.youtube.com/watch?v=_QLEERYS5C8 No-one seems to know why flywheels store energy. Not really. Bill Angular momentum. no, angular kinetic energy -- New Socialism consists essentially in being seen to have your heart in the right place whilst your head is in the clouds and your hand is in someone else's pocket. |
#45
Posted to uk.d-i-y
|
|||
|
|||
The mechanical bettery
On 24/08/2020 13:11, Roger Hayter wrote:
I find it simplest to avoid the question of whether it *stores* energy and just accept that it can provide energy to a system that slows it down to the same speed and orientation as the rest of the planet. And, symmetrically, you can provide it with energy to start it spinning again. Whether it is stored or simply doesn't exist when you are not using it is a philosophical point, to which the philosophical answer is that energy is conserved in the system containing the flywheel. But that is just words, what matters is that you can put energy in and take energy out, the conservation of energy being a property of the system rather than of the flywheel. Yes, all that makes sense. But I was trying to get to a deeper truth! Bill |
#46
Posted to uk.d-i-y
|
|||
|
|||
The mechanical bettery
On 24/08/2020 17:39, Chris Hogg wrote:
Bill might just as well ask why a mass travelling in a straight line stores energy. Why does it? Bill |
#47
Posted to uk.d-i-y
|
|||
|
|||
The mechanical bettery
On Monday, 24 August 2020 10:02:23 UTC+1, Dave Liquorice wrote:
On Sun, 23 Aug 2020 18:23:40 -0700 (PDT), tabbypurr wrote: All is fine until there is an accident. The flywheel dislodges and continues like a much more energetic panjanderam, demolishing everyone and everything in its very long path. Yes, though that's mostly solvable. 2 counterrotating flywheels in one casing with a mechanism to jam them together on impact. Er, Where does all the kinetic energy go? - friction - heat. where else? OK in theory you have equal an opposite amounts so they "cancel out". since they're geared together & balanced they have identical speed & energy storage But two identical cars traveling at the same speed in opposite directions into each other end up a right mess disspiating their kinetic energy, yep, they do what they're designed to I think you'd get a big BANG, the desruction of the flywheels and generation of lots of high speed shrapnel. you get what you design it to do. If you put teeth that interlock onto the flywheels & break when engaged, breakage is what you get. If you put a friction lining between them that brakes the flywheels within the time they have to stop without exceeding their tensile strengths, then stop is what you get. Etc. The latter might be possible to contain, they manage it with blade failures on jet engines. An outer case does allow for some degree of destructive breakage. And that generally will happen even if the flywheels are stationary. NT |
#48
Posted to uk.d-i-y
|
|||
|
|||
The mechanical bettery
On Monday, 24 August 2020 10:05:57 UTC+1, Clive Arthur wrote:
On 24/08/2020 02:36, tabbypurr wrote: On Sunday, 23 August 2020 12:34:19 UTC+1, Clive Arthur wrote: On 23/08/2020 12:13, N_Cook wrote: snip https://en.wikipedia.org/wiki/Fireless_locomotive Don't know about locomotives , but for road transport ,they came to an abrupt abondonment. All is fine until there is an accident. The flywheel dislodges and continues like a much more energetic panjanderam, demolishing everyone and everything in its very long path. These never caught on either... https://en.wikipedia.org/wiki/Gyro_monorail too many errors ...but it doesn't con men trying... https://www.litmotors.com/ what's con about that? The big issue people have with gyro balancing is that if things go wrong, stability is lost & carnage results. And IRL things go wrong & lawyers get greedy. NT The con is that, while it can balance, it can only be an impractical novelty, and I'm sure that Daniel Kim (Lit Motors owner) knows that. why? All these years and you just get a few seconds of video, usually without sound and without tripod. It's noisy - maybe that could be overcome - but it's constantly rocking about it's balance point, which can't be. I've seen footage of gyro stabilised vehicles. They rock about when the gyro speed is too low, otherwise they're stable. It seems to be quite usable. I'd think 4 wheels a more sensible option, but for a niche market I don't see any inherent large problem with gyro stabilisation. Ultimately 2 wheels & gyro is a less efficient layout, the problem is worse than the cost of 2 more wheels, but it's perfectly doable & some people want novelty. The gyros can only supply one-way torque for a limited time (newton-metre-seconds?) before they hit their 'end-stops', no way round that, so to balance, the thing has to actively push against a side force so that its weight counteracts it. In the large Brennan prototype for example, as the passengers move to one side, the car tips sideways the other way to maintain balance. I'm not making much sense of that. If you push on it with a finger, it will actively push you back, I mean actually move you back so that its weight balances against your finger. Of course, that's how it automatically leans into a curve. Imagine that in traffic with constant changing blustery side winds. the gyro stabilises it. I've watched a car drive into the side of a gyro stabilised 2 wheeler. It got knocked sideways but didn't fall over. Imagine one stationary near a solid object and trying to squeeze past - it would crush you. Surely it's basic sense that the driver knows it's not always completely upright. If they choose to squeeze a person between car & wall they have only their own foolish actions to blame. I think Kim revived the idea with a view to getting lots of investment and advance orders, he seems to have disappeared. An interesting subject though. There have been a few prototype vehicles, mostly very old, and Ford experimented with their 'Gyron'. There are some youtube videos of home made toys using the idea, I think a properly made say OO scale monorail would be fun, and maybe some sort of fairground ride - the idea of using a wire rope as a bridge is appealing. https://en.wikipedia.org/wiki/Ford_Gyron https://en.wikipedia.org/wiki/Gyrocar AIUI Russia were particularly interested in a national monorail system because it would save them so much on rails. Bridge savings are also attractive.. For cars there seems little real upside bar novelty. Given the bridge situation perhaps it would suit North Korea. NT |
#49
Posted to uk.d-i-y
|
|||
|
|||
The mechanical bettery
Robin wrote:
On 24/08/2020 13:11, Roger Hayter wrote: williamwright wrote: On 24/08/2020 10:59, Radio Man wrote: williamwright wrote: On 22/08/2020 17:27, harry wrote: https://www.youtube.com/watch?v=_QLEERYS5C8 No-one seems to know why flywheels store energy. Not really. Bill Angular momentum. That's just words. Bill I find it simplest to avoid the question of whether it *stores* energy and just accept that it can provide energy to a system that slows it down to the same speed and orientation as the rest of the planet. And, symmetrically, you can provide it with energy to start it spinning again. Whether it is stored or simply doesn't exist when you are not using it is a philosophical point, to which the philosophical answer is that energy is conserved in the system containing the flywheel. But that is just words, what matters is that you can put energy in and take energy out, the conservation of energy being a property of the system rather than of the flywheel. or you can just accept that the energy is real and its existence is intrinsic to the mass-energy equivalence in relativity - a theory which has been tested by a wide range of experiments (and applies to rotational energy as to other forms) I know nothing of this. I am just treating the flywheel as a form of magic box with defined propertiies, just as a way for simple people such as myself to look at it. -- Roger Hayter |
#51
Posted to uk.d-i-y
|
|||
|
|||
The mechanical bettery
On Monday, 24 August 2020 23:18:08 UTC+1, Clive Arthur wrote:
On 24/08/2020 21:37, tabbypurr wrote: On Monday, 24 August 2020 10:05:57 UTC+1, Clive Arthur wrote: snipped The gyros can only supply one-way torque for a limited time (newton-metre-seconds?) before they hit their 'end-stops', no way round that, so to balance, the thing has to actively push against a side force so that its weight counteracts it. In the large Brennan prototype for example, as the passengers move to one side, the car tips sideways the other way to maintain balance. I'm not making much sense of that. You can't exert a torque or force indefinitely without something to react against, which you don't have with two wheels. So to balance against a constant side force, the only way to do it is to use your weight. You need to push the force away to a position where your weight (the horizontal component) balances the applied force. I'm making no sense of most of that. I've seen enough footage to know it is workable, albeit generally not the most efficient use of resources, and of course real problems ensue if the gyro bearings seize. Billiard tables are afaik not relevant, and I don't see any particular difficulty in not going so close to walls as to create a hazard for cyclists. And yes it has been done, long ago, multiple times. It's seldom done now for the reasons I've addressed, nothing to do with not working. FWIW Schilovsky used to drive his gyrocar round London over a century ago. The only problem he encountered was asymmetric cornering ability due to having only one flywheel. NT If you lean against a gyro stabilised motorcycle or monorail, it will push against you, not just in the sense that a wall 'pushes back', but to physically move you back. This can be seen (briefly) in one of the Lit Motors video clips where Kim leans against the vehicle, it's also noted in the Brennan stuff, and is the way the vehicle automatically leans into corners - it's balancing the outward force with its weight. If you push on it with a finger, it will actively push you back, I mean actually move you back so that its weight balances against your finger.. Of course, that's how it automatically leans into a curve. Imagine that in traffic with constant changing blustery side winds. the gyro stabilises it. I've watched a car drive into the side of a gyro stabilised 2 wheeler. It got knocked sideways but didn't fall over. That's different. Yes, knock one with a brief transient and it will wobble and possibly slide, but hopefully remain 'upright'. Blow against one and it will lean towards you. Unlike a normal bike, you're insulated from the wind by the cabin, so you just get the buffeting for no obvious reason. Imagine one stationary near a solid object and trying to squeeze past - it would crush you. Surely it's basic sense that the driver knows it's not always completely upright. If they choose to squeeze a person between car & wall they have only their own foolish actions to blame. Say the vehicle is waiting at the lights, alongside a normal car, or worse, another gyro bike. A cyclist squeezes between and brushes the gyro bike. The bike leans into him, the force increases, the bike leans more, the force increases... Or you somehow put your foot, or your dog, under the vehicle on one side. Stationary vehicles shouldn't be inherently dangerous. AIUI Russia were particularly interested in a national monorail system because it would save them so much on rails. Bridge savings are also attractive. For cars there seems little real upside bar novelty. Given the bridge situation perhaps it would suit North Korea. Well, it might if it worked as well as first imagined, but it can't. Brennan's vision was long distance monorails in Australia, and there were somewhat fanciful pictures of wide carriages with billiard tables. You know when you're on a train and you pass another one at speed - imagine what that would be like as the gyros compensate for the violently changing side forces. The fact that it's not been achieved after over 100 years also indicates something. A great idea, but just not quite practical, though as an indoor novelty monorail it would be fun. This is an interesting piece... http://www.catskillarchive.com/rrextra/odgyro.Html |
#52
Posted to uk.d-i-y
|
|||
|
|||
The mechanical bettery
On 24/08/2020 18:32, Chris Hogg wrote:
On Mon, 24 Aug 2020 17:46:55 +0100, williamwright wrote: On 24/08/2020 17:39, Chris Hogg wrote: Bill might just as well ask why a mass travelling in a straight line stores energy. Why does it? Bill Why do two masses attract each other? Why do magnets attract each other? Why do the four fundamental forces exist and how do they work? Some things just are; they're the basics of the Universe. God did it! :-) If there's really no better explanation you don't need the smiley. Bill |
#53
Posted to uk.d-i-y
|
|||
|
|||
The mechanical bettery
On 24/08/2020 17:39, Chris Hogg wrote:
On Mon, 24 Aug 2020 15:22:28 +0100, The Natural Philosopher wrote: On 24/08/2020 10:59, Radio Man wrote: williamwright wrote: On 22/08/2020 17:27, harry wrote: https://www.youtube.com/watch?v=_QLEERYS5C8 No-one seems to know why flywheels store energy. Not really. Bill Angular momentum. no, angular kinetic energy Bill might just as well ask why a mass travelling in a straight line stores energy. Energy is a way of describing the work you need to do to stop it Guys: Energy is a character in a story. Its not real. What is real is the reading on your meters -- Gun Control: The law that ensures that only criminals have guns. |
#54
Posted to uk.d-i-y
|
|||
|
|||
The mechanical bettery
On 24/08/2020 17:39, Chris Hogg wrote:
On Mon, 24 Aug 2020 15:22:28 +0100, The Natural Philosopher wrote: On 24/08/2020 10:59, Radio Man wrote: williamwright wrote: On 22/08/2020 17:27, harry wrote: https://www.youtube.com/watch?v=_QLEERYS5C8 No-one seems to know why flywheels store energy. Not really. Bill Angular momentum. no, angular kinetic energy Bill might just as well ask why a mass travelling in a straight line stores energy. Because it ****ing well feels like it, mkay? -- Gun Control: The law that ensures that only criminals have guns. |
#55
Posted to uk.d-i-y
|
|||
|
|||
The mechanical bettery
On 24/08/2020 22:14, Roger Hayter wrote:
Robin wrote: On 24/08/2020 13:11, Roger Hayter wrote: williamwright wrote: On 24/08/2020 10:59, Radio Man wrote: williamwright wrote: On 22/08/2020 17:27, harry wrote: https://www.youtube.com/watch?v=_QLEERYS5C8 No-one seems to know why flywheels store energy. Not really. Bill Angular momentum. That's just words. Bill I find it simplest to avoid the question of whether it *stores* energy and just accept that it can provide energy to a system that slows it down to the same speed and orientation as the rest of the planet. And, symmetrically, you can provide it with energy to start it spinning again. Whether it is stored or simply doesn't exist when you are not using it is a philosophical point, to which the philosophical answer is that energy is conserved in the system containing the flywheel. But that is just words, what matters is that you can put energy in and take energy out, the conservation of energy being a property of the system rather than of the flywheel. or you can just accept that the energy is real and its existence is intrinsic to the mass-energy equivalence in relativity - a theory which has been tested by a wide range of experiments (and applies to rotational energy as to other forms) I know nothing of this. I am just treating the flywheel as a form of magic box with defined propertiies, just as a way for simple people such as myself to look at it. Far more sensible than accepting that 'energy' is 'real'... -- Gun Control: The law that ensures that only criminals have guns. |
#56
Posted to uk.d-i-y
|
|||
|
|||
The mechanical bettery
|
#57
Posted to uk.d-i-y
|
|||
|
|||
The mechanical bettery
Clive Arthur wrote:
You simply can't generate/supply a torque indefinitely without something to react against.Â* If you could 'meddle with the laws of physics' in such a way, satellite manufacturers would be beating a path to your door. How does a reaction wheel differ from a flywheel then? |
#58
Posted to uk.d-i-y
|
|||
|
|||
The mechanical bettery
On 25/08/2020 09:34, Andy Burns wrote:
Clive Arthur wrote: You simply can't generate/supply a torque indefinitely without something to react against.Â* If you could 'meddle with the laws of physics' in such a way, satellite manufacturers would be beating a path to your door. How does a reaction wheel differ from a flywheel then? Both gyros and reaction wheels are used, I think gyros are more compact, but they both need to be periodically reset with a burst of rockety gas stuff (or something reacting against the earth's magnetic field I think, or maybe solar wind, ask an expert) if required to compensate for a constant applied torque. Reactionless torque is like reactionless drive, it needs a special sort of physics found only on YouTube. -- Cheers Clive |
#59
Posted to uk.d-i-y
|
|||
|
|||
The mechanical bettery
On Tuesday, 25 August 2020 09:21:39 UTC+1, Clive Arthur wrote:
On 25/08/2020 01:31, tabbypurr wrote: On Monday, 24 August 2020 23:18:08 UTC+1, Clive Arthur wrote: snipped You can't exert a torque or force indefinitely without something to react against, which you don't have with two wheels. So to balance against a constant side force, the only way to do it is to use your weight. You need to push the force away to a position where your weight (the horizontal component) balances the applied force. I'm making no sense of most of that. It's not intuitive, but it is fundamental to their operation! You simply can't generate/supply a torque indefinitely without something to react against. If you could 'meddle with the laws of physics' in such a way, satellite manufacturers would be beating a path to your door. Look at it this way. Without external influence, you can't hold a bike leaning to one side using gyros, the best you could do is keep it there for a very short time while your gyros precessed over their useful range. It's an inverted pendulum and needs constant correction to remain upright. You can hold a bike leaning to one side if you let it rest on your finger, and this is the quiescent situation which the gyros enforce - touch a balancing bike and your finger is pushed and moved back dynamically until the system is at rest leaning against it. I've seen enough footage to know it is workable... I'd like to see that footage. Yes, it can be made to work after a fashion, but not well enough for other than novelty or demonstration purposes. Lit motors has a lot of animations but very little real video - you'd think no-one had access to a video camera. I don't know if it was a scam from the start or if there was a sudden 'oh ****' moment when they made their prototype some years ago. Google away, there have been a handful of gyro cars, some filmed. Eg https://www.youtube.com/watch?v=TTCVn4EByfI Schilovsky's vehicle was an impractical novelty too, it demonstrated a principle. It was a demonstrator for his proposed railway. He drove it around London, it worked. One of the best photographs from the Brennan monorail shows his young daughter sat in a small scale monorail car balanced on a wire rope several feet off the ground. You can see how this might easily impress investors, though I think Brennan was genuine. (Gyro bearing seizing is a non-issue from the safety perspective if you have two.) The 2 are connected together. If one stops, so does the other. If that didn't happen, things would be much worse! NT |
#60
Posted to uk.d-i-y
|
|||
|
|||
The mechanical bettery
On 25/08/2020 19:28, wrote:
On Tuesday, 25 August 2020 09:21:39 UTC+1, Clive Arthur wrote: snipped Google away, there have been a handful of gyro cars, some filmed. Eg https://www.youtube.com/watch?v=TTCVn4EByfI That sort of makes the point. Barely jogging speed, rocking around. A fun toy. Even the later track test shows the driver really fighting with the steering. Schilovsky's vehicle was an impractical novelty too, it demonstrated a principle. It was a demonstrator for his proposed railway. He drove it around London, it worked. After a fashion. 'Around London' is a bit of a stretch, and driven slowly and gingerly according to contemporaneous reports. I think the Schilovsky vehicle, in addition to the gyros, used moving mass to help balance, maybe that was later. He only had the one gyro, so cornering was rather asymmetric. (Gyro bearing seizing is a non-issue from the safety perspective if you have two.) The 2 are connected together. If one stops, so does the other. If that didn't happen, things would be much worse! In which vehicle are the two connected? Not Lit, not Brennan. That's one of the safety features, if a gyro fails you still have the one to hold you steady enough for a while. There's one of Brennan's prototypes in the York railway museum, maybe about the size of a very small car. Such a shame, but it's been shown to be inadequate for practical use several times over the last century. Almost there, but never quite. This guy has a lot of fun with them... https://www.youtube.com/watch?v=jGYXJjRfgTM NT -- Cheers Clive |
#61
Posted to uk.d-i-y
|
|||
|
|||
The mechanical bettery
In article , The Natural Philosopher
writes On 24/08/2020 17:39, Chris Hogg wrote: On Mon, 24 Aug 2020 15:22:28 +0100, The Natural Philosopher wrote: On 24/08/2020 10:59, Radio Man wrote: williamwright wrote: On 22/08/2020 17:27, harry wrote: https://www.youtube.com/watch?v=_QLEERYS5C8 No-one seems to know why flywheels store energy. Not really. Bill Angular momentum. no, angular kinetic energy Bill might just as well ask why a mass travelling in a straight line stores energy. Energy is a way of describing the work you need to do to stop it Guys: Energy is a character in a story. Its not real. What is real is the reading on your meters God invented work. And to do work you need energy. So she invented energy. Simples. -- bert |
#62
Posted to uk.d-i-y
|
|||
|
|||
The mechanical bettery
On Tuesday, 25 August 2020 22:55:33 UTC+1, Clive Arthur wrote:
On 25/08/2020 19:28, tabbypurr wrote: On Tuesday, 25 August 2020 09:21:39 UTC+1, Clive Arthur wrote: snipped Google away, there have been a handful of gyro cars, some filmed. Eg https://www.youtube.com/watch?v=TTCVn4EByfI That sort of makes the point. Barely jogging speed, rocking around. A fun toy. Even the later track test shows the driver really fighting with the steering. Schilovsky's vehicle was an impractical novelty too, it demonstrated a principle. It was a demonstrator for his proposed railway. He drove it around London, it worked. After a fashion. 'Around London' is a bit of a stretch, and driven slowly and gingerly according to contemporaneous reports. I think the Schilovsky vehicle, in addition to the gyros, used moving mass to help balance, maybe that was later. He only had the one gyro, so cornering was rather asymmetric. (Gyro bearing seizing is a non-issue from the safety perspective if you have two.) The 2 are connected together. If one stops, so does the other. If that didn't happen, things would be much worse! In which vehicle are the two connected? Not Lit, not Brennan. That's one of the safety features, if a gyro fails you still have the one to hold you steady enough for a while. There's one of Brennan's prototypes in the York railway museum, maybe about the size of a very small car. Such a shame, but it's been shown to be inadequate for practical use several times over the last century. Almost there, but never quite. This guy has a lot of fun with them... https://www.youtube.com/watch?v=jGYXJjRfgTM it seems to work in that demo NT |
Reply |
|
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
BLD-3 Lithium Ion Battery Specs Mechanical and Electrical. | Electronics Repair | |||
toro GTS OHV 21" lawnmower "mechanical hard parts" - seeking source |
Home Repair | |||
WTD: Sony DV MECHANICAL ADJUSTMENT MANUAL | Electronics Repair | |||
Mechanical jamming problem with CD shuffle carrier mechanism | Electronics Repair | |||
Toshiba SD-2805 5-disc carousel open/close tray mechanical problem | Electronics Repair |