http://www.besslerwheel.com/forum/viewt ... 9848#79848
The reason, I suggest, that this thread has no traction with any capable builder is because it is ill defined - i.e. the objectives & the experimental methodology to be used - IOW's a lack of clear direction & consensus.
Add to that the angst, recriminations, patch protecting & unsupported claims of violated Laws & it presents a picture of confusion - boys capturing farts in a bottle watching them bounce around.
Greendoor .. FYI, there is a subtle difference between steel springs & rubber bungy's - as rubber heats its length shortens & width/diameter increases, contrary to other Energy storage devices - this may have a positive effect.
But by all means stick with Peq's tether or conversely wrap the bungy around the wheel groove & take Cf's out of the equation as per my link above.
energy producing experiments
Moderator: scott
re: energy producing experiments
Fletcher: The trebuchet tethered throw does not provide a very good opportunity to be measured by a photo gate timer. I think you could throw into a five gallon bucket but photo gates need needle threading accuracy. You would have to throw into a net and then let the motion of the net trip the photo gate. Well: maybe that is not too hard an engineering problem. The net could have a low mass: hum. Well you have got me thinking again.
What I was going to say is that greendoor’s smaller drive pulley wheel idea has a mounted wheel which makes itself readily available to be timed with the photo gates. If the pulley is made light and the drive pulley is made much smaller than the outer wheel (as mentioned by broil concerning moment of inertia) the energy increase is already large (5.5 times for a ten to one ratio of outer wheel to driver wheel) and can be measured in a spinning mounted wheel. If you then choose to throw with a tether you can multiply the energy again up to a total of 20 times, or more, the original energy. The small drive pulley is not just a launcher it will make energy on its own.
I see no loss to centrifugal force in the tether throw, you take a hit from air resistance but that is it.
What I was going to say is that greendoor’s smaller drive pulley wheel idea has a mounted wheel which makes itself readily available to be timed with the photo gates. If the pulley is made light and the drive pulley is made much smaller than the outer wheel (as mentioned by broil concerning moment of inertia) the energy increase is already large (5.5 times for a ten to one ratio of outer wheel to driver wheel) and can be measured in a spinning mounted wheel. If you then choose to throw with a tether you can multiply the energy again up to a total of 20 times, or more, the original energy. The small drive pulley is not just a launcher it will make energy on its own.
I see no loss to centrifugal force in the tether throw, you take a hit from air resistance but that is it.
I would suggest that the simplest and least contentious validation of energy creation would be the vertical rise of the driver mass (or equivalent). No need for photo gates or calculations - we just want to see a small Mass drop 1 unit of Height, and then ascend 1 + X units of Height. A simple video would prove all we need to know.
IMO, we have two simple options: a tether (for a sudden pull) or a hammer (for a sudden push). The trick is to apply the impulse with a vertical vector, and avoid any horizontal vector. That might be a little difficult with a rotating flywheel - although we are trying to stop the flywheel as quickly as possible. I still believe that high elasticity is required, so there is minimal time delay.
A tether has a small problem in that it adds extra mass which may need to be accelerated, so we want to engineer as little movement of the tether, and as little mass as possible. I wonder if steel guitar strings might be good for the job?
I wonder if something like Bessler's toy page hammer & anvil mechanism could be used to 'kick a ball' upwards? I sometimes wonder if the 'game played by children in the streets' was simply kicking a ball. Or marbles as one translation suggests - very similar principle, just a smaller scale. I do think the image of kicking a ball over a goal post is a good example of the transfer of momentum with resulting high energy that we desire.
I would suggest that any measure of energy be based on simple vertical rise. The rest would be history. Bessler said as much with his comments about a 4:1 (or possibly greater) increase in lift. I think with the unavoidable losses, we should be aiming for at least 4 x the momentum we know is necessary for a free fall pendulum return rise.
IMO, we have two simple options: a tether (for a sudden pull) or a hammer (for a sudden push). The trick is to apply the impulse with a vertical vector, and avoid any horizontal vector. That might be a little difficult with a rotating flywheel - although we are trying to stop the flywheel as quickly as possible. I still believe that high elasticity is required, so there is minimal time delay.
A tether has a small problem in that it adds extra mass which may need to be accelerated, so we want to engineer as little movement of the tether, and as little mass as possible. I wonder if steel guitar strings might be good for the job?
I wonder if something like Bessler's toy page hammer & anvil mechanism could be used to 'kick a ball' upwards? I sometimes wonder if the 'game played by children in the streets' was simply kicking a ball. Or marbles as one translation suggests - very similar principle, just a smaller scale. I do think the image of kicking a ball over a goal post is a good example of the transfer of momentum with resulting high energy that we desire.
I would suggest that any measure of energy be based on simple vertical rise. The rest would be history. Bessler said as much with his comments about a 4:1 (or possibly greater) increase in lift. I think with the unavoidable losses, we should be aiming for at least 4 x the momentum we know is necessary for a free fall pendulum return rise.
My last comment about a pendulum made me think I might be missing the simplest method of all.
What would be so wrong about having the flywheel strike a suspended pendulum bob? And while i'm using the word 'flywheel', it could be a balanced beam and may not need to fully rotate 360 degrees in one cycle - making it easier to engineer a striking mechanism.
Edit: In this case, we want to apply 100% horizontal vector, with no vertical vector. It's just a 90 degrees rotation difference that can easily be engineered.
Edit again: forget this. This is basically Newton's balls, and the problem is that the heavy mass does not transfer all momentum to the ball - it keeps going. So the flywheel would strike the pendulum bob, which would take off, but most of the momentum would be left in the flywheel.
Stuffed if I know ... always so close but so far.
What would be so wrong about having the flywheel strike a suspended pendulum bob? And while i'm using the word 'flywheel', it could be a balanced beam and may not need to fully rotate 360 degrees in one cycle - making it easier to engineer a striking mechanism.
Edit: In this case, we want to apply 100% horizontal vector, with no vertical vector. It's just a 90 degrees rotation difference that can easily be engineered.
Edit again: forget this. This is basically Newton's balls, and the problem is that the heavy mass does not transfer all momentum to the ball - it keeps going. So the flywheel would strike the pendulum bob, which would take off, but most of the momentum would be left in the flywheel.
Stuffed if I know ... always so close but so far.
Last edited by greendoor on Sat Oct 16, 2010 1:34 am, edited 2 times in total.
re: energy producing experiments
Pequiade .. photo gates aren't necessarily required at all, especially if threading thru a needle as you say.
The obvious solution is a back board marked with distances & a video camera [cell phone will do I suppose] - as long as you can down load the stream & count frames & time - then velocities can be reliably estimated.
Especially as you are talking about serious orders of magnitude of Energy creation so whether the marker board is a little behind the setup & the angle of filming won't make much difference to the result - you aren't looking for a 10% gain which might get lost in the noise.
It is my contention & explanation that whilst there is air drag it is actually the geometry of the vectored forces as Cf's pull the tether tight & its connection with the rim that firstly stops the flywheel & also stops the system delivering any useful gain in Energy - this means that any combination will not result in a Net increase in Pe, IINM.
I guess that's the beauty of experiments & videoing them.
EDIT: crossed over post with Greendoor.
The obvious solution is a back board marked with distances & a video camera [cell phone will do I suppose] - as long as you can down load the stream & count frames & time - then velocities can be reliably estimated.
Especially as you are talking about serious orders of magnitude of Energy creation so whether the marker board is a little behind the setup & the angle of filming won't make much difference to the result - you aren't looking for a 10% gain which might get lost in the noise.
It is my contention & explanation that whilst there is air drag it is actually the geometry of the vectored forces as Cf's pull the tether tight & its connection with the rim that firstly stops the flywheel & also stops the system delivering any useful gain in Energy - this means that any combination will not result in a Net increase in Pe, IINM.
I guess that's the beauty of experiments & videoing them.
EDIT: crossed over post with Greendoor.
re: energy producing experiments
If the center pin is stationary and there is no air resistance or other friction, an object will rotate around the center pin on the end of a string forever with no loss of motion. If the center pin does not move centripetal force balances centrifugal force. The direction of motion changes but not the magnitude. If the center pin can move, such as a spinning cylinder or a spinning wheel, or a trebuchet counter weight, then you get a standard linear momentum transfer. At least that is what all my tests have shown.
I have used overhead video tapes of cylinders and disks. I used strobe light photography of disks on a ‘frictionless plane’, and photo gate timers on arms and wheels. All data collected shows a linear momentum transfer from one object to the other.
By “needle threading� I mean that the pin or flag must pass through the photo gates in the same why each time. The flag trips should not be a mix of diagonals or off to the side. Proper passes are easy to do on mounted wheels, but my gates can not be used to time baseballs. I already have the gates so I will test the energy producing small drive pulleys.
I have used overhead video tapes of cylinders and disks. I used strobe light photography of disks on a ‘frictionless plane’, and photo gate timers on arms and wheels. All data collected shows a linear momentum transfer from one object to the other.
By “needle threading� I mean that the pin or flag must pass through the photo gates in the same why each time. The flag trips should not be a mix of diagonals or off to the side. Proper passes are easy to do on mounted wheels, but my gates can not be used to time baseballs. I already have the gates so I will test the energy producing small drive pulleys.
re: energy producing experiments
Thanks for the clarification Pequaide - bit pressed for time today - will make a drawing asap of what I mean by geometry of force vectors & why Cf's stop the flywheel in a vertically mounted wheel without Energy gain, also for clarification purposes.
re: energy producing experiments
Hi guys,
just a quick sketch.
Any merit in a device as shown below? No reset mechanism though.
Axle is "empty".
Hope I'm not going back too many paces!
just a quick sketch.
Any merit in a device as shown below? No reset mechanism though.
Axle is "empty".
Hope I'm not going back too many paces!
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I only realized too late that life was short.
Dr What - thanks for that drawing. It's very similar to what I had in mind when I suggested a flywheel striking a pendulum bob.
My reservation about this is that the pendulum bob will take off with higher velocity than the flywheel, and once physical contact is ended, the Impulse ends. This means that only a small portion of the momentum is transfered, and the flywheel keeps moving.
Your drawing has given me an idea to work around this. You have drawn the pendulum attached to the wheel, and I believe you intend this to also act as the driver mass. I thought that was a good idea - and probably is - but this would mean that the pin strikes the rod close to the bob end. This is the 'fast' end of the pendulum, so physical contact will be lost very quickly.
For the sake of a POP experiment, imagine the pendulum is much lower down, so the pin can strike very close to the pivot point. This gives us a huge leverage advantage. The rod would be moving at much slower velocity at that small diameter. This means that when the flywheel pin hits the rod, it will be like hitting a brick wall. Physical contact will be maintained for much longer. If we design it right, we should be able to completely stop the flywheel, which is the goal. Meanwhile, the bob will accelerate to high velocity ...
I'm excited about aspects of this design .. thanks DrWhat
My reservation about this is that the pendulum bob will take off with higher velocity than the flywheel, and once physical contact is ended, the Impulse ends. This means that only a small portion of the momentum is transfered, and the flywheel keeps moving.
Your drawing has given me an idea to work around this. You have drawn the pendulum attached to the wheel, and I believe you intend this to also act as the driver mass. I thought that was a good idea - and probably is - but this would mean that the pin strikes the rod close to the bob end. This is the 'fast' end of the pendulum, so physical contact will be lost very quickly.
For the sake of a POP experiment, imagine the pendulum is much lower down, so the pin can strike very close to the pivot point. This gives us a huge leverage advantage. The rod would be moving at much slower velocity at that small diameter. This means that when the flywheel pin hits the rod, it will be like hitting a brick wall. Physical contact will be maintained for much longer. If we design it right, we should be able to completely stop the flywheel, which is the goal. Meanwhile, the bob will accelerate to high velocity ...
I'm excited about aspects of this design .. thanks DrWhat
Assuming we pass the POP test, I think the 'pendulum as driver mass' idea of DrWhat could be used with a pin at a smaller diameter, so that it strikes close to the pivot as i described above. The catch is that the protruding pin would hit on the rod going down. This could be engineered out, but using a mechanism rather like the Bessler toypage hammer & anvil, so the pin would be out of the way going down, but back in protruding position ready to strike the rod when necessary ...
If we can just demonstrate a height gain by any means, the mechanism for the wheel will follow. I want to stick to the simplest experiment that shows a height gain first.
I think the idea of impacting a pendulum rod close to the pivot end is an exciting idea for transferring slow/heavy momentum to a lighter mass to achieve higher velocity ...
A simple experiment: dangle a ruler downwards, suspended at the top by your fingers. Pressure from your thumb can represent slow/heavy momentum. If you push at the bottom, the ruler moves slowly. But if you push closer to the top, the bottom end of the ruler swings much further and faster.
Further idea: a model train on a track on a table. This is our heavy Atwoods mass. A string from the train runs over a pulley, and we drop a small driver mass over the end of the table to accelerate the train. When the mass hits the floor, the train reaches maximum momentum. Arrange a pendulum so that when the train is at maximum momentum, it strikes the pendulum rod close to the pivot.
This would take some careful tinkering, and a solid grasp of the maths at stake. But i'm thinking this basic design should be able to prove or disprove the basic theory. Friction will be the killer, which is why we need to design a generous surplus of momentum, i.e. a large ration between driver mass and train/Atwoods mass.
What I would hope to see is that when the driver mass is released from table height, the train would slowing accelerate, getting faster and faster until the driver mass hits the floor. At that point, it should have acquired a generous amount of Momentum, courtesy of the Force of gravity acting over many seconds. At the point, the train would slam into the pendulum rod, at slow speed but with considerable force. We would want to see the train come to a halt, but the pendulum bob fly upwards. If we use the same mass for the driver weight and the pendulum bob, we can easily measure the height the bob rises compared to the table height.
Pequaide - do you think this is a fair trial for your idea? I can see there are plenty of opportunities for a poor build to fail. I'm sure that any builder who is determined to prove you wrong would end up with a non-runner if built with that mindset. But if built by somebody who understands the concept at stake here, do you think this is a fair experiment?
Edit: a problem I can see is if there is too much mass in the pendulum rod ... this is a potential loss, hence the need to design for plenty of surplus momentum. I.e. - make the train heavier, accelerate it slower but for longer, ending up with more momentum ...
If we can just demonstrate a height gain by any means, the mechanism for the wheel will follow. I want to stick to the simplest experiment that shows a height gain first.
I think the idea of impacting a pendulum rod close to the pivot end is an exciting idea for transferring slow/heavy momentum to a lighter mass to achieve higher velocity ...
A simple experiment: dangle a ruler downwards, suspended at the top by your fingers. Pressure from your thumb can represent slow/heavy momentum. If you push at the bottom, the ruler moves slowly. But if you push closer to the top, the bottom end of the ruler swings much further and faster.
Further idea: a model train on a track on a table. This is our heavy Atwoods mass. A string from the train runs over a pulley, and we drop a small driver mass over the end of the table to accelerate the train. When the mass hits the floor, the train reaches maximum momentum. Arrange a pendulum so that when the train is at maximum momentum, it strikes the pendulum rod close to the pivot.
This would take some careful tinkering, and a solid grasp of the maths at stake. But i'm thinking this basic design should be able to prove or disprove the basic theory. Friction will be the killer, which is why we need to design a generous surplus of momentum, i.e. a large ration between driver mass and train/Atwoods mass.
What I would hope to see is that when the driver mass is released from table height, the train would slowing accelerate, getting faster and faster until the driver mass hits the floor. At that point, it should have acquired a generous amount of Momentum, courtesy of the Force of gravity acting over many seconds. At the point, the train would slam into the pendulum rod, at slow speed but with considerable force. We would want to see the train come to a halt, but the pendulum bob fly upwards. If we use the same mass for the driver weight and the pendulum bob, we can easily measure the height the bob rises compared to the table height.
Pequaide - do you think this is a fair trial for your idea? I can see there are plenty of opportunities for a poor build to fail. I'm sure that any builder who is determined to prove you wrong would end up with a non-runner if built with that mindset. But if built by somebody who understands the concept at stake here, do you think this is a fair experiment?
Edit: a problem I can see is if there is too much mass in the pendulum rod ... this is a potential loss, hence the need to design for plenty of surplus momentum. I.e. - make the train heavier, accelerate it slower but for longer, ending up with more momentum ...
Then there's a split in the road here. Some group want to use height while the other want to use velocities (me). Imo both are equally good if performed correctly. To call one simpler over the other is not correct, it depends on your inventory.
For instance this "new" experiment that popped up a few pages back should also be investigated. I attached a summary of what's it about. You would need some weights, pulleys, a rod/tube, skateboard wheel and some glue. Experimental wise you will need either a photo gate or some inductors and an triggerable oscilloscope.
The parameters are chosen so to eliminate experimental error. You either get times near each other (CoE is violated) or times with a factor of 3 difference.
For instance this "new" experiment that popped up a few pages back should also be investigated. I attached a summary of what's it about. You would need some weights, pulleys, a rod/tube, skateboard wheel and some glue. Experimental wise you will need either a photo gate or some inductors and an triggerable oscilloscope.
The parameters are chosen so to eliminate experimental error. You either get times near each other (CoE is violated) or times with a factor of 3 difference.
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re: energy producing experiments
Excellent broli: I had set in my mind to construct this very same experiment but I was going to rotate the bar in a vertical plane by off setting the descending mass. But I think I will get more data from the double pulley wheel first.
You could also have a .5 kilogram object on one side at one meter and 5 kilograms on the other at .1 meters. If one side was more difficult to rotate wouldn’t it wobble?
You could also have a .5 kilogram object on one side at one meter and 5 kilograms on the other at .1 meters. If one side was more difficult to rotate wouldn’t it wobble?
re: energy producing experiments
Assuming that the bar is weightless you will get a 10:1 rotational RPM difference, which produces a same velocity for each weight. Because the bar cannot be weightless the ratio will be more like 8:1 to 6:1 depending on the weight of the bar relative to the weight of the weights.
This does not prove anything other than constant force produces constant acceleration, which is common knowledge.
This does not prove anything other than constant force produces constant acceleration, which is common knowledge.
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- WM2D rotational acceleration test.
Weight Ratio is 10:1 while radius ratio is 1:10
Damian
I have had a lot of experience using leaf and rod spring. There is a strange drag effect with these type of springs. Mine killed the spin all to fast when I tried something similar to what you have drawn. But there are other effects to pay attention to. But for now I have put these spring test to the side for now. But good luck on your studies.
Alan
I have had a lot of experience using leaf and rod spring. There is a strange drag effect with these type of springs. Mine killed the spin all to fast when I tried something similar to what you have drawn. But there are other effects to pay attention to. But for now I have put these spring test to the side for now. But good luck on your studies.
Alan