Priority Claim

[ovyyus]

...an old friend of mine [Reiner] many years ago showed me experiments of steel balls dropped onto 'cooled' steel plates...

http://www.besslerwheel.com/forum/viewtopic.php?t=397

Fletcher, your comment about Tinhead [Reiner] in my 10 year old 'Chilled Steel Bounce' topic now makes a little more sense.

[Fletcher]

Reading that thread was a blast from the past Bill - Tinhead was always a sensible fellow & not inclined to go off on wild goose chases.

But anyways, as I was building Grimer's sim I was thinking how to tweak it to get a better result & that thought came flooding back - of course a spinning wheel has Cf's which separate air in temperature & pressure gradients - then new air enters the system.

Perhaps there's an angle to be worked here if we all put our minds to it ?!

Remember, the answer was very simple, so much so that Karl was surprised no one had thought of it.

ETA: in sim world the elasticity of both contact body's must be the same e.g. 1.00 - if one is lower, say 0.5, the collision parameters will give results according to the lower elasticity - it makes sense.

It raises the question whether both real world surfaces would need to be chilled ? - or just one ?

......................

Elections here in Fiji today, wish us well.

[Grimer]

@ Fletcher

Did you stop the simple pendulum at its apogee in the manner required as shown in the Gravity Pulse Motor - Mark 2, here?......

http://www.besslerwheel.com/forum/weblo ... .php?e=159

In other words, did you hold the simple pendulum at it apogee until the compound pendulum picked it up to form a single balanced beam?

[Fletcher]

@ Fletcher

Did you stop the simple pendulum at its apogee in the manner required as shown in the Gravity Pulse Motor - Mark 2, here?......

http://www.besslerwheel.com/forum/weblo ... .php?e=159

In other words, did you hold the simple pendulum at it apogee until the compound pendulum picked it up to form a single balanced beam?

Hi Frank .. I'm sure I described the actions in a previous post, & there was a sim to watch to show what happened, but I'll step thru it again.

N.B. the sim used a spar to replace your massless spring in your blog, set to elasticity of 1.0 [as was the bob] so the interaction was identical to using a perfect spring.

1. the bob driver is released & it swings down due gravity acceleration losing PE & gaining an equal amount of KE at the same vertical height [1 for 1 : there are no pin joint losses or air friction losses etc, else the KE gained would be less than the PE lost] - at 6 o'cl the bob has maximum KE.

2. the bob impacts the spar - some momentum is transferred.

3. the spar rotates CW lifting the blue counterweight off its stand - the bob rebounds CCW & as it climbs it loses KE & gains PE until it reaches its maximum vertical height where it has zero velocity & zero KE - it is not locked 'in space' at this time & is free to fall again.

4. the blue & yellow connected counter weights continue to rotate due momentum & energy given to them from the bob driver - this Rotational energy is exactly equal to the PE lost by the bob driver.

5. the CW rotating counter weight system is decelerating because of imbalance to the left blue side - left to its own it will rise a certain height & reverse direction to settle on its stand again eventually.

6. the cwt system is decelerating & losing RKE - at the same time the bob driver is rising after impact & the idea is the yellow cwt right hand side will meet up with the rising bob [whether on there own or by locking in space the bob at its maximum height achieved] - in the sim the bob arrives at max height first before the cwt system finishes decelerating & reverses direction.

7. N.B. if the bob was locked in space to await the arrival of the yellow cwt section it would not happen, or if it did because it was a perfect system they would arrive together & both be motionless i.e. no RKE, no residual momentum or angular momentum.

8. in the sim I built [as opposed to Tarsiers sim where he locked the two together at their closest point, one oscillation only] I let the bob driver fall again - whilst falling the cwt system reversed direction so the spar was moving slowly CCW when the bob driver impacted again - there was another momentum & energy exchange with rebounds in both directions as you would expect.

9. the cwt system started to decelerate again due imbalance - the bob got an additional 'nudge' from the CCW moving spar & rose to a greater height [below horizontal] than previously - and the spar decelerated until the yellow cwt section & the bob driver ALMOST met up exactly ready for coupling.

10. at their closest proximity they are coupled together - the system has NO momentum or RKE & is stationary - there is NO residual momentum or RKE to cause further rotation of the system.

N.B. this is a simulation environment [conservation laws in play] - we would not expect to see residual momentum or RKE without the addition of an external torque to the system - if you can identify somewhere in your GPM design that inertia is mitigated in favour of gaining residual momentum or RKE then it would have a chance of working in a real world build with actual real losses to contend with.


Hope that explains things fully, as I see the sim working.

The short answer is I did not hold it at apogee [Tarsier did] until the second oscillation when they were closest.

[Grimer]

Thanks.

I'll have to think about it. It sounds sensible?

What happens with your sim if it is locked at number 3?

Edit: Forget it. I can see that's clutching at straws. Ah, well. At least it shows the benefit of not being a builder. :-)

I've just seen your reply below. Thanks again.

One has to look for a different principle than merely introducing a time delay. I can see that now.

[Fletcher]

Same as Kaine's Frank - if it is locked in space & waits for the very slow moving cwt system to catch up with it it will wait a very long time, as the cwt system is decelerating rapidly because of imbalance in the other direction.

[Grimer]

Trouble was, I couldn't understand what Tarsier was saying - the fact that our previous confrontations hadn't been too cordial didn't help. However, I've understood you well enough.

It also means that what I have written about the Milko is also bollocks since it was based on the same principle - and what I was about to write about a pendulum swinging in from the perimeter of the Bessler and back again to perfectly balance the wheel would also have been bollocks too.

Fortunately, the fact that I was going to depend on a single pendulum there made me worried since Bessler referred to the pendulums acting in pairs - so I thought - suppose I had pendulums swinging in from both sides - the wheel would be completely balanced which is good - but one of the swings would be acting against the other wouldn't it?

Ah! I see - not necessarily - :-)

I have another idea based on the Russian Rattleback which seems to have some promise. It's also relevant to the double pendulum swing - so I'll clear the decks and concentrate on that. It even has some WM2D inspiration. :-)

[Fletcher]

Glad I could be of some help Frank - Kaine had summed it up pretty well - sometimes when we are heavily invested in an idea it takes someone elses perspective to see & point out the show stoppers.

What I like about the critiquing process is that we all learn something & the donor can move on again to something else, as you are doing - cheers.

[Grimer]

Glad I could be of some help Frank - Kaine had summed it up pretty well - sometimes when we are heavily invested in an idea it takes someone else's perspective to see & point out the show stoppers.

What I like about the critiquing process is that we all learn something & the donor can move on again to something else, as you are doing - cheers.

And that is why people should not be analy retentive with their ideas but publish them freely.

[Grimer]

Before Tarsier and Fletcher had shown me I was talking bollocks with my GPMs and extended Milkovic I had intended to show the above diagram with only the green pendulum swinging, the idea being for the simple pendulum to get back to its reverse apogee before the compound pendulum (CP), i.e. the rest of the wheel, could use up the CP's energy.

T&F showed that this wouldn't work so I'm now proposing the blue simple pendulum swings in the opposite direction at the same time. This means that the system is completely balanced at all times and that the pendulums work in pairs, which should please Bessler.

Of course it also means that the two pendulums are acting against each other since the green one is pulling the wheel clockwise (CW) and the blue one is pulling the wheel counter-clockwise (CCW). Consequently there's no net turning of the wheel.

Still, we do at least have two of the factors under control which is a good place to start. :-)

Oh, and in case you're wondering about the pale blue arrows, they represent the gravitational wind blowing steadily down on both sides of the wheel.

(to be continued)

[Grimer]

If we cut the wheel down the middle and turn the left half upside down then we will have the left hand pendulum pulling up instead of down, pulling CW, pulling the same way as the same way as the right hand pendulum.

The wheel will still be balanced providing the pendulums are synchronized. No overbalance weight is needed to drive the wheel.

Of course, there's one small snag as you've probably noticed. The gravitational wind has to blow upwards on the left hand side and no one has yet found a way to achieve this.

(to be continued)

[Grimer]

Since we can't get the gravitational wind to blow upwards perhaps we can modify the action of the blue pendulum in some way that it acts on the wheel axle as though it is pulling upwards. Perhaps we can introduce a mechanism between the pendulum and the axle which converts counter-clockwise rotation into clockwise rotation.

I'm sure you're all familiar with the way that a car engine achieves this. The engine doesn't change it's direction of rotation when it sends the car into reverse. It brings into action an extra gear, a reverse gear.

So if we introduce a gear or its equivalent between the pendulum and the axle, instead of the pendulums opposing each other they will reinforce each other. In effect the gear is acting as a commutator.

Amazingly enough one member has very recently reported on a design which does just that.

On the Community Buzz Overbalance thread Ralph writes .....

"My present design now being built has a rotary devise that performs the same properties as a commutator, its either on or off, or in the process of switching."

..... which is exactly what is needed. If he can execute his design successfully he will be the first person since Bessler to have a device which harnesses the gravitational wind.

Let's wish him every success.

For non-members who don't have access to Community Buzz I'll past the wise words of Cloud camper who recognised early on that a commutator was an essential feature of a successful wheel.

13 6 12
Commutation is the key - it's back to the future baby!

18 8 12
Absolutely spot on Ben. What you're describing is a commutation mechanism.

No internal combustion, electric, or steam engine has ever operated without such a system.
This is the function of the camshaft/valve mechanism in an IC engine or the commutator in an electric motor.
The steam engine has a valve system as well.

21 8 12
In the electric motor, the commutator switches magnetic fields at precisely
the right times to keep the armature turning.

18 9 12
What's happening here? At the top of the forward swing the child is taking all the accumulated PE and switching (commutating) it over to an arc of smaller radii. Note this occurs when the mass (the child) is at a complete stop. The child is in fact the commutator in the system and instinctively knows what to do.

21 1 13
No other motor either electric, IC or steam can operate without a switching system, ie commutator or valves, why should JB's wheel be any different?

[zoelra]

Grimer,

Not "Uncle's Toy" but I thought you would find it interesting.

https://www.youtube.com/watch?v=QzIG9stFXSI

[Grimer]

Indeed - especially the videos which show him making the gears - what a brilliant craftsman.

If the uncle's toy is a viable proposition then he would be someone who could easily make it.

[Grimer]

Glad I could be of some help Frank - Kaine had summed it up pretty well - sometimes when we are heavily invested in an idea it takes someone else's perspective to see & point out the show stoppers.

What I like about the critiquing process is that we all learn something & the donor can move on again to something else, as you are doing - cheers.

And that is why people should not be analy retentive with their ideas but publish them freely.

Thanks to help from Fletcher and Kaine I've now been able to move on and see what the next step must be.

I freely admit I was so shattered when they eventually got through to me in showing that I was making an unwarranted assumption about the rate of decay of compound pendulum motion that I was tempted to delete the relevant posts on my blog.

I resisted that temptation since I felt it would be a good object lesson not to jump the starting gun.

After taking time off to regroup I now understand what needs to be done to increase the transfer of energy from the simple to the compound pendulum.

More later.