Greendoor get's what he wants so bad.

[nicbordeaux]

By popular demand ("Nick .. humour greendoor & do his experiment & video it would yuh ? - put him out of his misery"), I'll give up a worthwhile experiment I've been working on for a while. It fits in with the bouncy ball wheel fling stuff, I intended to make a worker integrating it; but heck, who cares ?

So it's like this greendoor, you have this force over time theory and neither you or the guy who came up with a baked bean can with some marbles and claimed to create energy in unlimited quantities have been able to do better than a baked bean can with two marbles.

You liked my tethered weight stuff being flung, but it doesn't suit your needs, which is quite OK, because the experiment has nothing to do with your theories.

So, this is what you do if you want force over time. You got your bike wheel, you got a small mass on it. And this is where it's money time or moment of truth, you also have a tethered weight. Yeah, you can say, I know that, you already show us the tethered weight fling.

But this time, your prayers have been answered 'cos I'm going to give you a massive secret Ii could have before, but didn't think it worth it) : use a bloody yoyo. The yoyo will untether at fast rpm, loads o' force, but it will take a long time to reach the end of the tether.

For the Bessler clue guys, look no farther for the toy he refers too, yoyos have been around since monkies were still monkies and lived up trees. "All children play with in the streets" or whatever the clue is. " "Dog reaching the end of his tether"... etc etc... Yoyo was a popular, cheap (handmade, just a piece a wood with a groove) toy in Bessler's germany.

Let me tell yawls, this is the great Bessler secret, he had yoyos all inside that darned wheel. And also, by popular request, I am giving, yes folks, giving, Greendoor what he needs to prove or disprove.

Alea jacta est.

[greendoor]

Well dog-gone it if that ain't the durndest thing I ever did hear'd, cowboy ...

Pequaide has already introduced us to the yo-yo ... the NASA de-spin device no less. So I guess Buzz Lightyear beats Woody yet again.

I've seriously thought about yo-yos, or lawn-mower pull starts, or vacuum cleaner retractible power cords ... I haven't really gone into any details about the things i've look at and dismissed. But since you bring it up, here is my thinking about coiled up tethers in general ...

I think a coiled up tether may be the opposite of what I want. What i'm looking for is a way to transform heavy/slow momentum into light/fast. So the faster the transformation, the better. Coiled up tethers, or springs for that matter, delay the time. Not to mention the extra friction and reduced elasticity that they bring.

To simplify our mind experiment - think in terms of a slow moving bus - lets say it weighs 100 ton and is travelling at walking speed. What we want to do is to bring this bus to a complete stop, and use all that momentum to propel a man on a bike to a great speed.

Obviously a simple collision won't work. During the time of impact, force is shared equally. But because of the huge difference in mass, the bike accelerates much quicker than the bus is moving, and at that point the physical connection is lost, force ceases, acceleration ceases etc. So the end result is what we see in classic textbox collision theory ... the bus continues moving, at only a slightly reduced velocity.

If we could slam that bus into an immovable wall, bring it fully to a halt and capture all that energy in "something", and then give that "something" to the bike, so it could then proceed to accelerate long after the collision, we would be onto something ...

There was a fascinating thread some time ago about an invention that is an emergency braking system for runaway trains, huge ships that need stopping in a hurry, etc. Basically it amounts to a linear gear track that drives rotary gears (rack & pinion) which drives a gear up flywheel. The massive linear force is completely turned into spinning up a flywheel to high velocity. So the large moving mass is stopped suddenly, without breaking anything - because all the force is turned into Acceleration rather than Stress. The fast spinning flywheel can then be braked with friction pads and cooling over a long period of time. So this system is pretty much exactly what I need.

Can you see the Time difference? Rather than delaying the time of the Impulse (as a coiled up tether would do), we have a very fast Impulse time (more like the 'anvil receiving many blows' and 'shadow boxers' that Bessler alludes to)

Still looking for the simplest way to prove this. And no, I wasn't thinking specifically of you Nick when I said 'cowboy'. But I am aware that the basic principle will need a very well thought out experiment to prove anything conclusively. Although if it flings a small mass higher than it falls, then all hell will break loose. But what i'm saying is that a poorly executed experiment that fails to work doesn't necessarily mean the principle is flawed.

[nicbordeaux]

If we could slam that bus into an immovable wall, bring it fully to a halt and capture all that energy in "something", and then give that "something" to the bike, so it could then proceed to accelerate long after the collision, we would be onto something ...

Take wubbly's experiment. Store all the energy in a spring system. release the spring so that along the whole length of it's "unspring" it gives up all it's force (energy, call it what you will) to a light object.

The spring losses can be calculated. Whatever happens to what you transfer the stored force can be measured. And of course the energy of the initial big slow mass can be calculated, so you have a way of checking those spring loss calculations. zero error margin.

Or you could try a newton's cradle with a low release 18 kg bowling ball impacting a marble. Better than running a buss into a hapless cyclist.

[beapilot]

Peek a boo. Da cood it ea boo. Tee tot ta ta.


Edited: (Additional Information)
No humor, shame. Enjoy a good laugh. For the one who gave me a red dot can not enjoy life.

[Fletcher]

We went thru spring options Nick on pequaides thread - any method of energy storage was discounted by the protagonists as unworkable & not in the spirit of what was trying to be achieved - go figure.

I actually did some sims [with screen shots posted] of a large slow mass impacting a spring, compressing it, locking the spring end impacted when compressed, then unlocking the end in contact with the lighter mass, & letting it push away & accelerate the light mass as fast as it could - the result was that the spring materially moved sideways a measure - spring was compressed slowly [long time] & uncompressed very fast [quick time] - total energy was conserved [using a perfect spring analogue] - that was the same as a perfectly inelastic collision would give which wubbly ably demonstrated later with the atwoods thread, IINM.

Well, the upshot was that springs were out as was any method of storing Pe.

The problem with springs, in a nut shell, was apparently that they store kinetic energy turning it into mechanical potential energy & then back into kinetic energy again - IIRC, greendoor said that storing Ke was not the same as storing momentum - go figure.

So the problem with using momentum [which btw is an accounting tool to balance the mass x velocity books] is that the bigger the ratio the slower the compression & the faster the release - so they wanted a cylinder & sphere's tethered bola type arrangement to 'suck' the momentum out of the flywheel by stopping it, then give it by way of acceleration to the weight to be hoisted - what is not realized is that there must be a medium of transmission between objects i.e. physical interaction, & that medium is not interested in momentum math but in energy transfer.

N.B. newton's cradles work well for same masses i.e. one will stop dead & the other will take on its velocity [less small losses] - if the impacting mass is greater than the mass of the impactee the impactor does not stop but continues to move on thru with residual velocity, so it can never give up all of its momentum as velocity gain to the impactee - it can exchange energy though but will still have residual velocity & Ke not transferred across.

See if your creative mind can do better than mine & find that elusive mechanical harvesting technique that allows a large mass to stop dead AND transfer its momentum/energy to a smaller mass completely ;7)

[FunWithGravity2]

Hello all,

Not that good at the math, but i wanted to add my 2 cents. I know for the sake of calculating the energy gained it is much easier (i think) to figure out the calculations if the impacting mass stops. But why are you trying to make the math easy, the object is to maintain momentum while still launching/resetting/lifting or whatever you want to do with your weight. So forgive me for being a simpleton but can someone explain why, other than for reasons of calculating KE gain would we want to completely stop the large mass. Is it not easier to reset the large mass if it still retains some of its momentum.

If the obvious answer eludes me please let me know.

Crazy Dave

[Fletcher]

It is not necessary to stop dead the large mass - just end up with more Pe than you started with, or residual velocity if in a circular environment - if a bigger ratio helps then so be it.

The trouble is dave we are not attempting to analyse any complete design committed to paper so that we can work out the math for it - until someone comes up with a mechanism that bridges into one all the separate components proposed then one guess is as good as another - but even, taking your example of the big mass still having velocity, how does the Pe stack up for the entire system start to finish ?

[greendoor]

Peek a boo. Da cood it ea boo. Tee tot ta ta.


Edited: (Additional Information)
No humor, shame. Enjoy a good laugh. For the one who gave me a red dot can not enjoy life.

Beapilot - we have tolerated your rude behaviour for too long. You have become an irksome troll.

Look - some of us understand that you have a big handicap - deafness. You are also very young, and a bit of a geek. So we accept that your social skills are not that great. But you are undoing any sympathy we might have for you by being a troll.

So bog off.

[greendoor]

Hello all,

Not that good at the math, but i wanted to add my 2 cents. I know for the sake of calculating the energy gained it is much easier (i think) to figure out the calculations if the impacting mass stops. But why are you trying to make the math easy, the object is to maintain momentum while still launching/resetting/lifting or whatever you want to do with your weight. So forgive me for being a simpleton but can someone explain why, other than for reasons of calculating KE gain would we want to completely stop the large mass. Is it not easier to reset the large mass if it still retains some of its momentum.

If the obvious answer eludes me please let me know.

Crazy Dave

Hi Crazy Dave - the obvious answer is that the heavy flywheel is balanced, and therefore never needs resetting. It can stop in any position and be ready to go again. It's the driver mass that falls that needs resetting. If we can get that back up again, it can fall again and accelerate the flywheel again.

To remind you of the basic principle - we are using the flywheel (or Atwoods system, or some other heavy balanced mass system that can be accelerated) to store momentum. Momentum is mathematically equivalent to Force * Time (as well as equivalent to Mass * Velocity). We are using this heavy balanced system to SLOW down the fall of a small overbalancing mass. The idea of SLOWING down the fall is to prolong the Time that the force of gravity available. This is mathematically equivalent to allow the mass to fall a much greater distance than it actually falls to gain the equivalent Force * Time.

You have to realise that if the driver mass actually fell in freefall for the same amount of time, it would be moving a lot faster. The heavy balanced system accelerates much slower (because F = MA which means A = F/A which means that the force acting on the driver mass is DIVIDED into accelerating the flywheel. The acceleration is is proportionally less, therefore the velocity attained is proportionally less. So we end up with a very heavy mass system with low velocity, which we then need to transfer to the small mass (which will then experience a proportional increase in velocity).

This seems like a long winded chain of events. BUT - the reason to get excited about this is because it is possible to create large amounts of momentum by increasing the ratio between the masses.

In a nutshell - we are increasing the Time of fall, thus increasing the Momentum that can be accumulated over a specific Mass falling a specific Height. This part is undeniable classic Newtonian physics. The disputed part is whether those large amounts of Momentum can be transfered back to the small mass. Conservation of Momentum suggests this should be theoretically possible. The implication of that is at odds with Conservation of Kinetic Energy (but fortunately there is no law about Conservation of Kinetic Energy).

Fletcher has expressed the problem very well.

[greendoor]

See if your creative mind can do better than mine & find that elusive mechanical harvesting technique that allows a large mass to stop dead AND transfer its momentum/energy to a smaller mass completely ;7)

Fletcher - many people insist that springs store Energy, not Momentum. That didn't come from me - i'm just repeating what Pequaide, and most physicists have said. I have to agree though. Energy is such a nebulous word with many meanings, including this fictitious 'potential energy' which is a bit like an IOU for energy.

I have been very influenced by Frank Grimer and his work regarding Stress and Strain. Can't say I understand him totally, but he's been a big influence in what I currently believe.

Momentum can only be stored in mass moving at velocity. A spining flywheel is a good example of stored Momentum. Which of course can also be considered a form of Energy storage - the two concepts are just maths abstractions of the fundamental Mass and Velocity. It gets a little confusing with a flywheel because the mass is moving at different velocities depending on distance from the axle. This is why Pequaide prefers Cylinders, where the mass is concentrated pretty much at the same velocity. But that just helps the maths - there is no reason to avoid solid flywheels, it's just harder to analyse.

AFAIK - to transfer Heavy/Slow momentum to Light/Fast, we need to use Impulse (which is Force * Time and equivalent to Momentum, not Energy). This aligns with Impact, or reaching the end of a tether. Hopefully a smooth transfer of force, not a noisy, hot, lossy impact, but an impact nonetheless.

I see that being a conversion of Momentum into Stress/Strain, and then that Stress/Strain is used to propel the lighter mass. Newtons Balls being the obvious example - but the problem I can see is that as soon as the lighter mass accelerates away, the transfer of Force ceases. So the heavy mass can only deliver a partial amount.

Pequaide's yo-yo appears to be workable - because obviously the unwinding tether allows the force to continue to transfer while the small mass accelerates away. This is also easy to see that this is a Force * Time transfer, not a Force * Distance transfer. Unless we run out of tether, we can continue transfering force for as long as it is available.

A spring seems to be doomed to be a Force * Distance transfer (equivalent to energy rather than momentum). The force diminishes with distance - even with proportional springs there is a distance limit where the force ceases. Momentum requires velocity - there is no way to store velocity in a static device. I think the problem with trying to store momentum in a spring is that the spring will only accept up to it's designed force * distance limitation, and any excess force would be expended to ground as Normal force. This is locking the door after the horse has bolted. As I see it anyway.

A rack & pinion seems workable to me. The force could be constantly applied for accelerating a flywheel, until the force available drops to zero.

I think there could be a hydraulic solution too.

[Fletcher]

Greendoor .. there seems to be a lot of overlap with clay's current thread but I'll continue on anyways.

Yes, the problem is the transference - I am glad you have some ideas worth exploring about how to maximize this - perhaps someone will work out how to incorporate them into a design that shows a good result ?

Q for you ? - in pequaides cylinder & sphere's broli went a step further & devised a two arm deployment system so that the end masses were accelerated by the slowed & stopped flywheel [he turned his on its side so that Cf's were in action & no gravity input] - this showed a complete transfer - anyways, he started the sim with an input of rotational energy [torque or motor I can't remember for limited time] - in your scenario the flywheel is turned by an imbalance weight [either one bola or an attached drive weight ?] - if one of the masses is flung up high it should achieve a height [Pe] but the drive mass will stay at or nearest its lowest Pe of position [even if the apparatus is locked down] - so it should be able to calculate the new positions of masses & sum their potential energies - if we assume that the drive mass is the same as the deployed masses [one of which is hoisted] then the sums seem relatively easy - as long as the flung mass has gained more Pe than is lost by the other deployed mass & drive mass then the system is a winner - is that a fair & simple test that a competent builder could make ?

[alexjrgreen]

Perhaps I'm missing something here. Why not transfer momentum from a slow heavy mass to a light mass using a lever?

Like this: http://www.youtube.com/watch?v=OHPEWCY1Db0

[greendoor]

A lever was the first thing I thought of too. The practical issues get fairly complex if you attempt to build. To make it strong enough the lever itself needs a lot of mass, which robs much of the momentum. Compared to a tether which can be very strong but light.

I've wondered if a scissorjack might still be the answer. Maybe a variation that multiplies the leverage of each section. Maybe constructed with a web of wires that needn't weight that much?

[alexjrgreen]

Gearing, then.

Which might offer a theory for the Buzz-Saw:

1. the outer ring is driven from the inner but is geared to rotate faster
2. the inner ring starts balanced
3. an extra, unbalanced weight is added at the top and falls, causing the inner ring to turn and drive the outer ring
4. when the weight reaches the bottom it falls into the faster, outer ring
5. it extracts energy from the (now balanced) inner ring as it rises back up
6. if it actually reaches the top, it falls back into the inner ring and starts the process again

Or not...

[path_finder]

Dear alexjrgreen,
Your description seems to be pertinent but don't give any useful practical indication on the most important point: the mechanism allowing the passage between the both rims.
If we admit the principle of two rotation speeds (outer and inner wheel), the only answer can be a variable speed for this mechanism (decelerating for a synchronization with the lowest speed, and accelerating for the highest speed), whatever the exchange complementary mechanism could be.
The way for obtaining this sinusoidal effect (on the mechanism rotation speed) can only be using some ellipsoidal gears.
I cannot diffuse my energy for everything and therefore (not specially interested with the BuzzSaw) I did not made any test in this direction.
Can we find any member/guest in this forum having any results for share in this matter?