How Difficult can it be?
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rasselasss
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re: How Difficult can it be?
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rasselasss
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rasselasss
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rasselasss
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rasselasss
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rasselasss
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Re: re: How Difficult can it be?
rasselasss wrote:The nearest example to explain this PM device has been in the past discussed on this forum many times...is that of a child on a "swing"using their body by moving their legs and shifting their body backwards and forwards so to continue swinging without being pushed.....you know when i started this i had to ask myself was this simple movement to a pendulum Besslers solution and if it is it could answer a lot of questions ...Karls response etc....i conclude this by stating this device WILL give P.M. with minimal precision...now the question arises "How to insert it inside a wheel"...anyone considering making this device the weight of the "bob"should be 4 times heavier than the moving (rolling) eye weight and the length of the pendulum arm to pivot is critical (giving a larger sweep of the bob thus slowing the eye movement making it easier to control as it rolls along its track ..the shorter the arm and swing arc causes the movement to be chaotic ,finding the "sweet"spot is difficult with much trial and error) also the track (horizontal)for the moving rolling "eye"should be dead centre of the"bob"to provide the alternating weight difference to each side of the "bob"with each swing of the pendulum ...As stated i conclude this part of this P.M. device ...A thought for those with vision,if you ever tried to stop a child on a swing quickly ,you can imagine the power needed to stop a pendulum of say 8 stone with a 2 stone moving rolling eye...it would knock a man over........Good Luck..
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rasselasss
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re: How Difficult can it be?
"Keeling",defeats many of our builds and designs here and is mentioned often on this Forum I have shown in the above quote how we can manipulate gravity inside a pendulum so it never comes to rest or stops once started with a gentle push.There is no secret its there in plain sight for all to see ………Controlled timing is what keeps it going as said before my wife calls the movement "flip-flop"....
re: How Difficult can it be?
Sounds like an interesting idea.
That child on a "swing"using their body by moving their legs and shifting their body backwards and forwards so to continue swinging without being pushed pumps energy into the system in resonance (with the right timing to the current state) so that total energy of the system accumulates. At the expense of eaten and stored sandwiches.
It is the stopping of accumulated momentum that will knocks you over; that's why it's easier (with caution!) to stop that swing when its about to return in mid-air.
I suspect this proposal will be in unstable equilibrium: Just right, or it drops.
Like the chaotic behavior in this hopping pendulum: https://www.besslerwheel.com/forum/view ... 320#168320
Theoretically it could hop as long as I like, but at an increasing need of accuracy of initial values (like spring settings).
In practice it sooner or later enters an unknown, like wind swirls, bumps, dirt or other random stuff occurring. It topples/keels anyway unless totally still and helped by static friction and the right bump or grain of sand.
That's way all those papers utilizes power consuming active controls.
In case of your swing, the swing frequency (Length/mass dependent) should somehow match the rotational speed of the wheel, or it gets out of synchronization.
With free-swinging pendulums, for example, you can make those pendulums swing outwards so their arms point almost always at the 12-o'clock position: but only when sync'ed just right.
As far as I understand that rolling eye, it has its own frequency in relation to its track when it goes back and forth.
Maybe there's a track shape that can provide the timing-feedback it needs to help to push the whole thing into synchronization. That would be something!
What do you have in mind? A position dependent latch?
As long as its activation costs less than it eventually gains then we have a winner!
Why is this in the off-topic section?
That child on a "swing"using their body by moving their legs and shifting their body backwards and forwards so to continue swinging without being pushed pumps energy into the system in resonance (with the right timing to the current state) so that total energy of the system accumulates. At the expense of eaten and stored sandwiches.
It is the stopping of accumulated momentum that will knocks you over; that's why it's easier (with caution!) to stop that swing when its about to return in mid-air.
Maybe you can explain how you got to that "4 times heavier" , but when you can show the principle with formulas then there are ways to find that sweet-spot.finding the "sweet"spot is difficult with much trial and error
I suspect this proposal will be in unstable equilibrium: Just right, or it drops.
Like the chaotic behavior in this hopping pendulum: https://www.besslerwheel.com/forum/view ... 320#168320
Theoretically it could hop as long as I like, but at an increasing need of accuracy of initial values (like spring settings).
In practice it sooner or later enters an unknown, like wind swirls, bumps, dirt or other random stuff occurring. It topples/keels anyway unless totally still and helped by static friction and the right bump or grain of sand.
That's way all those papers utilizes power consuming active controls.
In case of your swing, the swing frequency (Length/mass dependent) should somehow match the rotational speed of the wheel, or it gets out of synchronization.
With free-swinging pendulums, for example, you can make those pendulums swing outwards so their arms point almost always at the 12-o'clock position: but only when sync'ed just right.
As far as I understand that rolling eye, it has its own frequency in relation to its track when it goes back and forth.
Maybe there's a track shape that can provide the timing-feedback it needs to help to push the whole thing into synchronization. That would be something!
Sounds right.Controlled timing is what keeps it going as said before my wife calls the movement "flip-flop"....
What do you have in mind? A position dependent latch?
As long as its activation costs less than it eventually gains then we have a winner!
Why is this in the off-topic section?
Marchello E.
-- May the force lift you up. In case it doesn't, try something else.---
-- May the force lift you up. In case it doesn't, try something else.---
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rasselasss
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Marchello,this isn't just an interesting idea this is a P.M. pendulum and I've explained how to build it ...any size...,the bob 4 times heavier than the rolling ball ,the rod length determined by trial and error ,whats not to understand ,no springs no latches, one fulcrum ...build it ,shouldn't take more than two hours once you acquire the materials needed as stated I'm more involved in how to insert it inside a drum ….I've moved on to the next stage ….not really interested in answering questions...Good Luck with your build.
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Georg Künstler
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re: How Difficult can it be?
Hi rasselasss,
why don't you Show an Little Picture from that what You are seeing in this Special pendulum ?
I had seen in the castle Elz in Germany a children toy which has simulated the movment of two eyes. It was working in a flip flop mode, forever.
I looked at this Swinging as a tilt swing.
I see your Problem to take this movement and adapt it in a circle process, you said the next stage.
The way here is that you must extract the energy, and this is causing more imbalance.
I for my part have managed to close the circle process, also as you said without springs, in the one directional Wheel.
why don't you Show an Little Picture from that what You are seeing in this Special pendulum ?
I had seen in the castle Elz in Germany a children toy which has simulated the movment of two eyes. It was working in a flip flop mode, forever.
I looked at this Swinging as a tilt swing.
I see your Problem to take this movement and adapt it in a circle process, you said the next stage.
The way here is that you must extract the energy, and this is causing more imbalance.
I for my part have managed to close the circle process, also as you said without springs, in the one directional Wheel.
Best regards
Georg
Georg
re: How Difficult can it be?
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Last edited by silent on Mon Oct 04, 2021 6:28 pm, edited 1 time in total.
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rasselasss
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Silent,i used the simple ladder rack obviously in minature scale in two pieces ,sliding in up or down like an extending ladder then securing when the timing was correct .….some would say like Jacob's Ladder....keep it simple.....agor95...its a simple pendulum with a horizontal track for the ball running in the middle of the bob....as stated before no springs ,no latches ….a child could build it...Good Luck..