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Tue Oct 27, 2009 5:09 am PostPost subject:
cloud camper
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Hey Harv I was wondering if you might help me verify some of the physics of the test rig I'm working on without sticking your neck out too far and getting it all bloodied up! We don't even need to address the issue of potential OU. That will simply be an issue to be resolved by meters, so just looking at basic physics here.

The whole concept of the rig is to eliminate (as much as possible) the back mmf felt by the stator motor before the motor has to do any work to overcome it. Somewhat like a continual "latch system". I know that physical work is not a vector quantity and there is no such thing as negative work. Work is work and it is only a positive quantity. But what makes up work is force which is a vector quantity and can have sign and/or azimuth values. After the force is applied over a distance it creates or constitutes work which is then only a positive quantity.

So if the force is minimized or presumably brought to zero by continually reacting against an equal and opposite force, the integral ∫f⋅dl over a 360 deg cycle representing the work required would be the integral of a force of zero over the full cycle. Of course friction and eddy current losses in the system will apply along with cpu and stator motor overhead.

If there is an imbalance in the opposing back mmf's then the stator motor will have to do work in the amount of the difference of the imbalance to maintain the computer commanded phase angle(s). If the counterbalance is maintained perfectly around the cycle at all times then the overall force is zero (won't happen). If there are spikes and valleys in the force requirements at various points around the cycle (a sure thing) then what I'm predicting is the angular momentum of the stators will fill in the gaps, either speeding up or slowing down slightly to fill in where necessary. The computer will not react fast enough to compensate individually for each minor speed up or slow down event and is only monitoring on a larger scale (let's say once per cycle).

I'm predicting some rather severe spikes and valleys (particularly around the negative torque shear events on the AGW side). So to get
around trying to describe all that mathematically it seems to me the lazy empirical approach might work. This means running the system in GW mode only and applying a given load to achieve a certain operating rpm and noting the instantaneous power requirement (wattage). Then running the system again in strictly AGW mode to hopefully achieve the same instantaneous wattage at the same load and rpm. Then if the values are the same (crazy assumption I know) wouldn't this be empirical evidence the work being done by the GW side was a match for the work done by the AGW?

I guess my primary question for you is what do you see happening when nasty spikes and valleys on both the GW and AGW sides occur (more severe on the AGW). Do you see the whole concept coming apart or could you envision the 2 lbs of stator and motor armature mass acting to fill in the wild excursions in force requirements and smoothing the functions? What happens to an integral when there are severe spikes in the function or even discontinuities? Will the integral behave properly as the summation of + and - forces even with insane spikes in both GW and AGW back mmf forces? Very weird dynamics here.

Just trying to be sure I understand the physics here and haven't made some gross error in understanding. Take 5 minutes here and present a clear and concise answer Smile (or not Sad ) I'm sure you have forgotten more physics than I will ever know so I really appreciate your insights! (Oh geez, that was supposed to be a compliment, but now it sounds more like an insult! Crap! - sorry Harv!)
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Tue Oct 27, 2009 1:12 pm PostPost subject:
overconfident
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@CC,

I'm gonna stick my neck out a bit. I can't even do the integration, but what I do is visualize a curve, and the area under it. The wiki page has a nice curve displayed, which even looks like it might represent the reality of the magnetic interactions we deal with in machines like these.

http://en.wikipedia.org/wiki/Integral

You could say the blue portion represents the forces working against us (friction, lenz, oppositional magnetic force, etc.) and the yellow represents the forces acting in our favor.

The math should be able to deal with the spikes with no problem. The hard part is measuring them accurately.

Hit a golf ball. Huge spike when the club impacts the ball, then a gradual decline over a long distance, until the ball finally comes to rest and the work is done. Now hike down to where the ball lies, face the opposite direction and drive that ball back to where it started, another huge spike (an opposite force).

Or if you want to see some really spiky stuff, try a game of ping-pong.

What you're trying to do is find some way to shift the balance of forces, so there's more working in your favor and less working against you. Not an easy task, maybe an impossible task.

I have tried to address the problem in WhipMag with a configuration where the forces are doubled (simultaneous repulsion from the previous stator and attraction to the subsequent one) and a dynamic (rotating stator), odd-even asymmetry that works in our favor, allowing more interaction in the desired direction than undesired.

The Magnetically Assisted Pendulum is another good example. It's not spiky, but look at the difference between the swing directions. Now if we could only flip that rotor magnet at the high point, what would that graph look like?

Hope I'm not making myself look too stupid here,
OC
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Sat Oct 31, 2009 6:23 pm PostPost subject:
cloud camper
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Hey OC, thanks for the response - really good stuff! Kind of fun to compare notes and concepts. Are you still developing the latch system for the Whipmag? If you need some parts fabbed I would be glad to help.

I never got that interested in it as I envisioned it to operate at a relatively low rpm because of the latch action like valves in an IC engine I suppose although it could potentially be a torque monster in spite of a lower rpm. This would still be very practical. My 6" rig with just four stators produced a huge amount of torque. With 13 stators going the torque would be nuts! I don't remember seeing a proposal from you on how all the back mmf forces would be dealt with tho.

What I have tried to do with my concept is figure a way to deal with all the forces involved rather than just the ones we want. I'm certainly not saying I've attained it on my rig but was just trying to take a critical look at all or at least more of the forces we're dealing with. I think this is the reason most magnet driven projects fail as the devices always reach a point in the cycle where back mmf=forward mmf and then locks up. I think their needs to be a prime mover in the system but that mover needs to have as little force placed on it as possible. Thats what makes the concept different from an electric motor. Once you have removed all force on the prime mover in the system, there's nothing left to make it move so thats why my concept requires the motors just to maintain phase angles in an orderly way.

Still don't know if I can generate sufficient torque on the AGW side to counterbalance the GW but I've made some progress with the Halbach's. Next step is to measure the wattage required on the GW side then see if I can match it on the AGW. That should be a pretty good clue if this concept will work.

The AGW stators seem to act as a torque inverter (at least using the Halbach's) Whatever torque you apply on the input comes back out as a minus quantity. I think thats a pretty incredible phenomenon! Not sure if there's enough created to be practical but if it is, it will allow an equal and opposite force at the stator motor to offset the back mmf of the GW side. We'll see!

Let me know how I can help with development on your project!
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Sat Oct 31, 2009 8:43 pm PostPost subject:
overconfident
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cloud camper wrote:

Hey OC, thanks for the response - really good stuff! Kind of fun to compare notes and concepts. Are you still developing the latch system for the Whipmag? If you need some parts fabbed I would be glad to help.


I'm not doing any active development at the moment, but I have been thinking about it whenever I get a few moments free tim. Right now, my life is in complete chaos. The WhipMag 3 thread has most of my design notes, but is stagnating a bit now, until life gets out of my way.

cloud camper wrote:

I never got that interested in it as I envisioned it to operate at a relatively low rpm because of the latch action like valves in an IC engine I suppose although it could potentially be a torque monster in spite of a lower rpm. This would still be very practical. My 6" rig with just four stators produced a huge amount of torque. With 13 stators going the torque would be nuts! I don't remember seeing a proposal from you on how all the back mmf forces would be dealt with tho. [/qute]

Whipmag 3 will be a variable diameter rotor from about 16" to over 20" in diameter. It will have 8 rotor magnets and 13 stators (or vice versa). It will be highly modular and allow interchanging the stator and rotor magnets, ie. we will be able to mount the spinning magnets on the rotor if we want.

The sticky spot (back mmf) is actually 2 sticky spots, one in attraction and the other in repulsion as the rotor magnet passes. The "pivots" are designed to reduce the repulsive resistance. I haven't been able to figure out any way to reduce the attractive resistance.

cloud camper wrote:

What I have tried to do with my concept is figure a way to deal with all the forces involved rather than just the ones we want. I'm certainly not saying I've attained it on my rig but was just trying to take a critical look at all or at least more of the forces we're dealing with. I think this is the reason most magnet driven projects fail as the devices always reach a point in the cycle where back mmf=forward mmf and then locks up. I think their needs to be a prime mover in the system but that mover needs to have as little force placed on it as possible. Thats what makes the concept different from an electric motor. Once you have removed all force on the prime mover in the system, there's nothing left to make it move so thats why my concept requires the motors just to maintain phase angles in an orderly way.

Still don't know if I can generate sufficient torque on the AGW side to counterbalance the GW but I've made some progress with the Halbach's. Next step is to measure the wattage required on the GW side then see if I can match it on the AGW. That should be a pretty good clue if this concept will work.


Halbachs might help focus the field where you want it. Other than that, I don't see any real advantage. But good luck with that.

cloud camper wrote:

The AGW stators seem to act as a torque inverter (at least using the Halbach's) Whatever torque you apply on the input comes back out as a minus quantity. I think thats a pretty incredible phenomenon! Not sure if there's enough created to be practical but if it is, it will allow an equal and opposite force at the stator motor to offset the back mmf of the GW side. We'll see!


Write it up and name it after yourself, "The CC Effect".



Halbachs might help focus the field where you want it. Other than that, I don't see any real advantage. But good luck with that.

cloud camper wrote:

Let me know how I can help with development on your project!


It'll probably be next year sometime before I get back to any serious efforts.

Glad to see you're still active. Keep up the good work.

OC
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Sat Oct 31, 2009 9:39 pm PostPost subject:
bano
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I was gaming with Hollbach I am not very impressed Yes it is come some wright in the suppose which Hollbash positioned the pole but this is so so ... may be I not perfect buildt my Hollbash ... I do not known but my results with using from me magnets are very far from my waiting and dreaming supposes.May be the building Hollbash need from precisious and perfect magnets and design.. I wish You Cloud Damper more success than my tryes and designeds
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