Something just interesting happened. Out of seemingly nowhere an idea popped up. I made some sketches and then opened wm2d to run some tests. Of course it didn't work as expected. But then I discovered a strange side effect. I decided to delve deeper into this and was quite shocked at what I found.
For now I'll share the graphs. In the below attachments you see two graphs. The above shows the angular speed of the main wheel and below it the center of mass graphed as x and y. As you can see the latter moves in a circle on the right side of the y axis.
Tomorrow I'll reveal more as I need sleep, or sleep deprivation to make sure this isn't a mistake. But just felt like sharing it asap as I don't like holding concepts.
PS: another strange thing happened. Just when I started discovering the offset point of gravity it started to rain heavily. I then started to hear ticking which distracted me. What was happening was that the roof was leaking. The astonishing thing was that it was leaking right above my electric outlet where my pc was hooked at!
An interesting happening.
Moderator: scott
An interesting happening.
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re: An interesting happening.
Any further progress Broli?
The update is bad news. The problem is that I was using a motor to keep something synchronized and after some careful scrutiny the power was all accounted for in one rotation. Thus making the wheel balanced when the center of mass clearly seemed one sided.
In the video below a wheel can be seen with a smaller inner unbalanced wheel which is attached to a motor to the main wheel. The motor rotates this. Outside of the wheel I put the same smaller wheel with the same motor. This is the control wheel. When the motor of the small wheel on the main wheel does work to get the green weight up, the outside motor drops the blue weight equally. This causes both motors to do zero work. And the graphs confirm this.
So the motors are delivering no power to keep the system in its state, then is the wheel balanced? The answer is sadly yes, the wheel is perfectly balanced.
http://www.youtube.com/watch?v=UzBZtndxcfc
The idea came from "the principle" thread talking about weights going equally up and down yet causing an imbalance, which only looks like it in this case. But looking like and being are not the same.
I hope it sparks some other ideas for me and others.
In the video below a wheel can be seen with a smaller inner unbalanced wheel which is attached to a motor to the main wheel. The motor rotates this. Outside of the wheel I put the same smaller wheel with the same motor. This is the control wheel. When the motor of the small wheel on the main wheel does work to get the green weight up, the outside motor drops the blue weight equally. This causes both motors to do zero work. And the graphs confirm this.
So the motors are delivering no power to keep the system in its state, then is the wheel balanced? The answer is sadly yes, the wheel is perfectly balanced.
http://www.youtube.com/watch?v=UzBZtndxcfc
The idea came from "the principle" thread talking about weights going equally up and down yet causing an imbalance, which only looks like it in this case. But looking like and being are not the same.
I hope it sparks some other ideas for me and others.
re: An interesting happening.
Explain to me where the balance is Broli. It is obvious the drive motors will have to drive at different speeds to keep synced,but depending on mounting, they should be doing the same amount of work. Even so, the imbalance in the main disk appears to be good.
Your design is well thought out to solve a particular problem. I would green dot you, but I have already done so before.
Your design is well thought out to solve a particular problem. I would green dot you, but I have already done so before.
Perhaps I should correct myself. It's not really balanced at all angles. In fact it pretty much behaves like a pendulum. In the below video I attached a small circle between the two, this can be seen as the center of mass or the only mass acting on the main wheel. The video shows two wheels, one is given an initial push the other is not:
http://www.youtube.com/watch?v=n1APe2pDr8I
As you can see the CoM goes around in a circle.
If the connecting line between the two always went through the center of the main wheel they it would truly be heavier on one side.
http://www.youtube.com/watch?v=n1APe2pDr8I
As you can see the CoM goes around in a circle.
If the connecting line between the two always went through the center of the main wheel they it would truly be heavier on one side.
In this model small changes lead to big differences. Here's an example, I took the small wheel with the red weight and shift it to the left closer to the center of the main wheel. The one given an initial push seems to accelerate. The other with no push seems to have a higher CoM after its swing:
http://www.youtube.com/watch?v=TCNJ-Sp6BOw
And before you mention it no it's not due to the smaller wheels the colored masses are attached to (that would even not explain the accelerating case on the left wheel). I have chosen the small wheels to be 100 000 times smaller than the colored wheels, so they don't effect the CoM.
But I'm going to do investigate this very closely integrate the power of the motors and report back. Of course the motors seem to be all in sync as previously and thus suggest 0 total power input from them, but seeming is.....deja vu.
Edit: Added image as requested by greendoor and the wm2d file for whom cares.
http://www.youtube.com/watch?v=TCNJ-Sp6BOw
And before you mention it no it's not due to the smaller wheels the colored masses are attached to (that would even not explain the accelerating case on the left wheel). I have chosen the small wheels to be 100 000 times smaller than the colored wheels, so they don't effect the CoM.
But I'm going to do investigate this very closely integrate the power of the motors and report back. Of course the motors seem to be all in sync as previously and thus suggest 0 total power input from them, but seeming is.....deja vu.
Edit: Added image as requested by greendoor and the wm2d file for whom cares.
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- CartW1.wm2d
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Last edited by broli on Sat Aug 07, 2010 1:45 am, edited 1 time in total.
Thanks Broli - very ingenious. Could I please request that you upload an image to this side so that the links don't get lost in the future.
I like the way the swinging weights trace out a cardioid shape, with the indented part of the heart shape at 3 o'clock. This gives the appearance of the weights tracing out an imbalanced path when comparing the left with the right side.
However - it seems apparant to me that the weights have to accelerate and decelerate in order to trace out the indented/direction-changing shape. The weights would have to come to zero velocity at 3 o'clock while they reverse direction. It seem to me that the amount of acceleration and deceleration is equal (the shape being symmetrical along the horizontal axis).
This suggests to me that any energy gain from gravity is countered by an equal energy loss. Or if you prefer to consider momentum, as I do, the force x time on each side is identical. hence zero energy gain from gravity when all is said and done.
IMO, this is he problem with any system that has the axles rigidly linked together. Time becomes factored out.
IMO, Bessler gave us the necessary clues with his comments about dogs on tethers, and sum of the parts, and the toy jacobs ladder that always has a 'spare' thing that doesn't have it's own place and must perpertually pop up somewhere, etc, etc. A mechanism that allows a Time imbalance between ascending and descending.
FWIW.
I like the way the swinging weights trace out a cardioid shape, with the indented part of the heart shape at 3 o'clock. This gives the appearance of the weights tracing out an imbalanced path when comparing the left with the right side.
However - it seems apparant to me that the weights have to accelerate and decelerate in order to trace out the indented/direction-changing shape. The weights would have to come to zero velocity at 3 o'clock while they reverse direction. It seem to me that the amount of acceleration and deceleration is equal (the shape being symmetrical along the horizontal axis).
This suggests to me that any energy gain from gravity is countered by an equal energy loss. Or if you prefer to consider momentum, as I do, the force x time on each side is identical. hence zero energy gain from gravity when all is said and done.
IMO, this is he problem with any system that has the axles rigidly linked together. Time becomes factored out.
IMO, Bessler gave us the necessary clues with his comments about dogs on tethers, and sum of the parts, and the toy jacobs ladder that always has a 'spare' thing that doesn't have it's own place and must perpertually pop up somewhere, etc, etc. A mechanism that allows a Time imbalance between ascending and descending.
FWIW.