Mechanical battery.

[Radio Man]

Turning corners must be interesting if the wheel is vertical.

[Radio Man]

Angular momentum.

[N_Cook]

Wasn't there a totally above the rail (no counterweights below) gyro-stabilised monorail system somewhere, Ireland ISTR?

[williamwright]

That's just words.

Bill

[Clive Arthur]

<snip>

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.

[Roger Hayter]

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.

[Robin]

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)

[The Natural Philosopher]

no, angular kinetic energy

[Chris Hogg]

Bill might just as well ask why a mass travelling in a straight line stores energy.

[williamwright]

Yes, all that makes sense. But I was trying to get to a deeper truth!

Bill

[williamwright]

Why does it?

Bill

[Chris Hogg]

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! :-)

[tabbypurr]

-> friction -> heat. where else?

since they're geared together & balanced they have identical speed & energy storage

yep, they do what they're designed to

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.

An outer case does allow for some degree of destructive breakage. And that generally will happen even if the flywheels are stationary.

NT

[tabbypurr]

why?

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.

I'm not making much sense of that.

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.

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.

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

[Roger Hayter]

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.

[Clive Arthur]

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.

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.

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.

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.

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...

[tabbypurr]

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

[williamwright]

If there's really no better explanation you don't need the smiley.

Bill

[The Natural Philosopher]

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

[The Natural Philosopher]

Because it f****ng well feels like it, mkay?