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Thanks Steven,
I appreciate to hear this from you, sine you are an experienced motor builder
Cant wait for your results
It's better to wear off by working than to rust by doing nothing.Comment
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Jetjis
I am blown away by your designing ability. I wish I had 1/10th of your talent in CAD design and building ability. You are an inspiration for me to shoot higher. Do you out source your cuts for the engine parts or do you do that in house? If you out source it, are they online and could you share that resourse? There are a bunch of stator and rotor combo's I think about but never dreamed of designing and having them made the way you have. I have always had to make do with whatever I could canabolize from used equipment. You have set the bar high.
Thanks for showing the way
GeorgeComment
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Originally posted by Jetijs View Post
If you have Solidworks with Toolbox installed you can simply use standard bolts and nuts that already have predefined threads (you can easily modify those files).
BTW- would you be so kind as to share the SW files? It's not a big deal if you choose not to but I have a friend who would like to take a shot at the same design if you succeed. Exact dimensions and specs would greatly help him.Comment
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George,
Thank's for the kind words
I didn't quite understand that out sourcing part (my english could be better). I tried to fiend some commercial rotor/stator cores that I could use for our purpose, but I could not find anything online and when I visited the local motor rewinding company, all they had was simple induction motor cores with many poles that are very hard to wind like we need and even harder if we need bifilar windings. So I figured it would be easier to make a stator/rotor core by myself exactly as I need them. I bought some 0.35mm thick sheets of silicon steel from the motor rewinding company and gave them along with my CAD drawings to a guy, who works in a local laser cutting company. Now I have to glue/bolt the plates together in needed thickness. I already finished the rotor piece, tomorrow I will work on the stator and if everything will work out fine, I will post some pictures.
lighty,
thanks for the tip, I will try out the toolbox stuff. Also I will make all my CAD files available for download when everything is finished, because there is still some minor issues to solve and some dimensions can change in the motor building process. Just remind me later
Thank you,
JetijsIt's better to wear off by working than to rust by doing nothing.Comment
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Originally posted by nali2001 View Post
Steven,
Another fantastic video, thank you.
- question - can the same "Effect" be achieved if the "magnet" was the "core" of the Coil ?
- SchpankmeComment
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Core
Hi there Schpankme,
No since its field will just latch onto the secondary C core at the moment when gets close to it. And besides that you don't want a coil over a magnet since the permanent magnet is just that, 'permanent' and you are not supposed to enforcese a magnetic field directly upon its structure, if you do you can/will waste the magnet.
So as in the video what you want the flux from the magnet to be 'steered' to add to the overall strength of the coil's initial input field. What you want other words is that the coil on the main core section will 'saturate' that core section onto it is wound. So when that happens the flux from the magnet must seek another 'path of least resistance' and will jump the air gap (paper) and will go trough the secondary core. So this will add to the magnetic field of the coil. And when the coil is turned off, the field of the magnet will return again to the primary core as a preferred path of least resistance. So the secondary core is again free to move.
See the attached picture.
StevenComment
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Flux Path
Steven,Originally posted by nali2001 View Post
Many thanks for the picture; my thoughts were away to reduce the size of the valve.
The next question would be saturation of the rotor; on a dual valve, 22 inch DIA motor, with 3 inch DIA shaft. The picture attached shows a 10 inch rotor and 6 inch magnets. The core is spec'd at 3 turns of #4 wire (0.39 O.D.) 420 feet.
- SchpankmeComment
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Similarities
Schpankme and Steven,Originally posted by Schpankme View Post
I am more than happy to let you guys continue with this discussion, though it is a bit off-topic. The use of permanent magnets in these type of configurations is very similar to Flynn's Parallel Path technology, and is known to be useful for increasing torque. It does not increase efficiency, however, since it takes more power to push the PM field out of the core with the coil in the first place. You pay for doing the work, one way or the other. If you want to switch fast, you need more voltage to establish the current flow. If you don't apply more voltage, the rise-time of the current is very slow because of the increased inductance.
The test video is a little misleading, since it only shows the "steady state" current, and not the start surge and total power required to run the coil in both cases. It allows the physical structures to be a little smaller for the power, but does not raise the COP of the system by much. For lifting cars up at the end of a crane, this can definitely save energy, since twice the field strength can be created for half the power.
These ideas CAN be incorporated into the magnetic attraction motor designs, but they make field switching more complicated, and require more input power to do it.
Schpankme, if you are interested in building a model experimental motor, I recommend you start with something smaller than 22 inches in diameter, in case some aspects of your design don't work quite the way you intend. Just a suggestion.
PeterComment
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Motor
Hi there Schpankme,
I have seen your questions on overunity.com as well.
The motor you have drawn can not work. Since the permanent magnets will just couple together and stay that way. The two magnets in your design should be repulse to each other. So flip one around.
You must understand that the rotor should have a usable cross section that is equal or somewhat more then the cross section of your two coil/cores and magnets together. This is why Hildenbrand said that the rotor did oversaturate because he did not make his rotor big enough (that is, big it enough cross section accommodate all the fields at one time).
And when I look at your motor I see that the finger of the rotor is only wide enough to accommodate the flux of one coil/core and one magnet. So you need to increase the rotor finger width twice as wide as it is now.
In the attached picture you see a motor with the proportions about right. Remember to give a little overhead, and so have the rotor a little wider. And keep the coil/cores about the same cross section as the magnets. Just like the image.
Regards,
StevenComment
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Hildenbrand
Hey Guys,Originally posted by nali2001 View Post
Hildenbrand has a great machine, but this form is not about his designs. Please start a new thread if this is what you wish to discuss.
Thanks,
PeterComment
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Motor working.
Ok I have my version of the attraction motor running. Seems to be ok, although there are certain things that I seem to have overlooked in the design stage. And these are issues that to my knowledge have not yet be discussed on this board, and are somewhat important.
Well as you see I in the video thing runs just fine at about 1000rpm. Input at idle is 12v 2.8amp.
There are two opto’s that control the timing of the two coils. Via a mc34151p dual mosfet driver and two irf3205 fets.
Now here is the deal, as you can see the thing has some torque and can with some effort be stalled. Note as you can see, when you slow the thing down it starts drawing more current. So the question is, ‘is this due to back emf?’ well the answer is 90% no. You see, no design is ever totally free of back emf and since my rotor is solid steel, there likely is some back emf that causes amp draw. But that is in my opinion to a less extend. The major amp draw you see is because when you slow the thing down, you change the rpm, and by that also the pulse length. You see, when you stall the motor completely the coils are 'on' 100% duty cycle (in other words full on) and because of the low inductance (low ohm) value of the coils there is at 12v a huge amp draw. Like over 10 amps easily, so that is 120watt+. Now the reason why the motor is not drawing that 120watt while running is because of the ‘very short’ on-times. But when you slow the motor down, you increase the pulse length more, and so there is a bigger ‘window’ for the coils to draw more current. The only way to really make an attraction motor, that does not draw more current under load, is when you match the input voltage in such a way that the ohmic resistance of the coil will (at a predetermined input voltage) be the limiting factor for amp flow. But this is also problematic since you do not want a motor coil of like 30ohm since the inductance will give bad performance. But if you use a 0.5ohm coil you will have at 12v a potential of 12/0.5=24amp being drawn if the on time window is big enough(worst case). So in my opinion this is why the/this motor starts drawing more current when you slow it down. In fact you can see it for yourself near the end of the video where I stall it totally and it is using more than 10amp. Again because the ohmic value of the coil is not enough to restrict amp flow (within reasonable values) So there are some solutions to this: Lowering the input voltage and let ohms be the max amp regulator. Or chop the opto input triggers in multiple small pieces. Which I will try, but will in both cases probably results in less rpm. Have not really gone into the back spike capture but a simple one diode test, lit a 15orso watt bulb just fine and resulted in maybe a 1/10 of an amp less draw.
Here is the video:
http://www.krystyna.nl/Machine/MotorRun001.wmv
Regards,
StevenLast edited by nali2001; 01-22-2008, 10:21 PM.Comment
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Steven, interesting results and great video BTW
Here are some pictures of my stator and rotor before gluing:
And after the gluing procedure:
Looks fine, I doubt that there is a way of gluing the plates together more precise, because the laser cuts are not as precise as you think. The epoxy took about two days for curing because I was afraid that I may not put the plates together as fast as needed (it took about 1 hour) and I used way too less hardener. But it is fine now.
Thanks,
JetijsIt's better to wear off by working than to rust by doing nothing.Comment
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Originally posted by Jetijs View Post
Fantastic pictures, excellent workmanship; thank you for sharing.
- SchpankmeComment
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Great Work
Jetijs,
Excellent gluing job. There is no substitute for patient, boring, tedious, labor! People who only watch these forums think this is exciting stuff. But on the bench, it is just unglamorous, long hours of hard work!
Your dedication to detail, your skill with CAD, and your excellent photographic documentation are an inspiration to people all over the world.
Thanks for "blazing the trail" and showing everybody else what it takes to succeed.
PeterComment
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