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  • Bedini Window Motor question

    Hi all, I am about to construct a window motor and would like to know what kind of construction is better. I can get 100mmx50mmx25mm Grade 5 ceramic magnets and make the traditional looking motor or i can get smaller but more powerful neodymium magnets and mount them on a plastic bicycle wheel similar to a bedini wheel. Which construction would be better? Should the rotor in both cases be non magnetic? In a Window motor, should the magnets be as strong as possible?

  • #2
    window Motor magnets

    Originally posted by Zooty View Post
    Hi all, I am about to construct a window motor and would like to know what kind of construction is better. I can get 100mmx50mmx25mm Grade 5 ceramic magnets and make the traditional looking motor or i can get smaller but more powerful neodymium magnets and mount them on a plastic bicycle wheel similar to a bedini wheel. Which construction would be better? Should the rotor in both cases be non magnetic? In a Window motor, should the magnets be as strong as possible?
    I have constructed a few window motors.
    So this is my opinion and only just an opinion.
    I the neos are good but they are expensive to get in a very large size.
    What I believed I have observed about the window motors success is the area the magnets cover, the wider the magnets the more surface area they cover of the diameter of the rotor. This I believe is where the success lies.
    If you are prepared to spend big money on magnets I think neos would be a good choice for the experiment
    But as I said itís only what I think I have observed. Itís to complicate to write up why this is so. In this blog here right now. Maybe later
    Cheers Rod

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    • #3
      I got 10 4" x 1/2" x 1/4" N45 neo's. Can i use all of them on a window motor?

      Comment


      • #4
        Hi Zooty,

        Ive built a couple in my time. Ive used large ferrites (12 inch x 2 inch x 1 inch) before and they work great on a budget. You really get your mass weight up with this method too. My rotor weighs over 20 kilos.

        But if you want maximum power and induction you cant go past the neos. You will most likely have to use halls with big strong neos, trigger coils may work ok, but can be problematic with large neos. There are some good neos on Bedinis site, Ive got 6 of the 4 inch x 1 inch x 1 inch from there.

        Rod is right, you could write pages on the variations.

        You need to decide on your rotor size, the smaller it is and the closer spaced the faster it will go (safety concerns). Decide whether you want an all north rotor (you can use the half circuit on this) or full north south with the bipolar circuit. With the north south variant geometry will come into play, and you will need to determine how you will align and form your coils in regards to the magnetic poles on the rotor.

        Regards
        "Once you've come to the conclusion that what what you know already is all you need to know, then you have a degree in disinterest." - John Dobson

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        • #5
          Thanks ren. I just received the full sequential bipolar circuit from the R-Charge website. I have 10 of these neo's and i want to use them all if possible. They are only half an inch wide but 4 inches long. Am i right in thinking that as long as there is a north and south opposite each other around the rotor, it should work? What considerations would i need to take in to account for spacing?

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          • #6
            IF you wind your traditional window coil along the diameter of your rotor you need to have a north on one side and a south on the other, 180 degrees apart. Scribble it on some paper and you will quickly see there are only a set number of variations that will achieve this with equal magnet spacing. If you have seen JB's lab notes there is a variation of this where a 4 pole rotor is used nsns, with the coils offset, so that they do not pass across the diameter.

            IF you place your coils on the circumference (still in window style, not solenoid) you simply just build one coil to match the space between two magnets. This method makes it much easier to add multiple coils and remove quickly.

            Do you want to use a large or small rotor?

            Regards
            "Once you've come to the conclusion that what what you know already is all you need to know, then you have a degree in disinterest." - John Dobson

            Comment


            • #7
              To get 10 magnets around the rotor i have worked it to be 3 inches in diameter. Magnet width is 1/2" and the spacing between each one is also 1/2"
              Last edited by Zooty; 05-25-2011, 12:03 AM.

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              • #8
                Spacing importance

                Hey Zooty,
                With the motor displayed at the last conference, it is apparent large neos are the key for a torque motor.

                Rotor geometry and spacing is also supposed to be very important . I hope somebody more experienced can speculate on this . Maybe somebody who knows to use a magnetic simulator could suggest how to model magnets . For starters look at the video posted by rick that shows construction pics in a video . Apparently BM2 group is also supposed to contain some information about rotor construction for neo magnets.

                The rotor for a ceramic magnet motor can be made of mild steel , as it is supplied with the window motor kit b made by rick.

                Also explore using parallel resistors in the circuit . Hall trigerring is the key for making a useful motor . The newest innovation is supposed to be a digital controller which will be unvieled in the next energy conference in july.

                Rotor geometry , number of windings ,coil position , circuit resistor values , hall positioning are all variables that need to be optimised.

                Keep posting your progress ,
                Bhargav

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                • #9
                  window motor video

                  Not to forget that amazing informative video by Bedini on youtube energenx channel . Other wonderful videos are from Dadhav , minoly ( patrick and son ) . They were in particular hepful to me in understanding window motors.

                  You can learn a ton by looking at these guys work until now .

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                  • #10
                    I had to make a 8 magnet version because i broke one of the magnets The rotor is 2.25" diameter lasercut from from stainless steel in 3 parts to house the bearings. I am using the full sequential bipolar circuit ordered from r-charge.com. The problem i am having is at 12v it wants to oscillate without the wheel spining and it uses over 1amp of current. If i give the wheel a spin it takes of and current draw drops to 400ma. I am using the fwbr to send the spikes back to the source. The magnets are N45 neo's. The only thing i can think of is the wire is too short. I didnt put that much on there, probably 100 turns and it is thick compared to some but it is all i had at the time. Would it be a good idea to switch to hall sensors? Also, when using just half the circuit, it seems to be firing on every magnet pass. Is that right?

                    Comment


                    • #11
                      Switch to halls

                      Yeah , switch to halls . Most of your starting issues will be resolved including control over torque produced( so current consumption too ) .

                      I use 100 turn coils too with good effect . You can add another 2 coils of 100 turns each at the same location where you have your first coil . Parallel them just as though they would work individually . The motor will seem to increase in torque when you would do that. And better and better results also when you add coils all around the rotor.

                      It will be interesting to see results using them N45's as most have worked with the standard kit provided by Rick . Do share if you did further research on magnet spacing etc . And dont miss the video on the energenx channel and by Rick .

                      I have 80 magnets each 50 x 50 x 25 mm ( N50's) , just unsure about the spacing and geometry . I wish there was more concrete writeup's or information available .

                      Have fun ,
                      Bhargav

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                      • #12
                        Thanks for the help guy's. I tried a new coil with a small gauge wire and although the rpm has dropped a bit, the current draw has dropped from 400ma to 150ma. At 2.5v it draws 40ma but it's not very fast at all. I am looking for high rmp without the torque because i want to apply some coil shorting on a generator. Will hall sensors allow such a low current draw at 12v with good rpm?

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                        • #13
                          A good typical Hall sensor is the DN6851, datasheet here: http://www.yc-dz.com/productimages/1658324675.pdf
                          There are better sheets, but that one came up first in Google and they are the Hall's I use. Also, they are FREE, if you have a couple of spare PC case fans kicking around being useless.
                          I have whole pulse motors running that draw less than 10mA when using such Hall's..their consumption is around 8mA.
                          Neo's can be all North around a rotor or N/S/N/S, virtual Souths are your friend. As the magnet passes, it flips the polarity that the sensor see's (this one anyway). That means that every magnet will fire the sensor

                          You can get good experiment neo's from CD-Rom laser assemblies and much bigger ones from within hard drives. For the bigger ones, bend the metal they are on back with pliers and they will come off. They are flat and usually around at least N40 strength. Long thin ones can be scored across their middles on each side and then will break cleanly. That gives you squared magnets with N on one face and S on the reverse X 2

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                          • #14
                            Originally posted by Slider2732 View Post
                            A good typical Hall sensor is the DN6851, datasheet here: http://www.yc-dz.com/productimages/1658324675.pdf
                            There are better sheets, but that one came up first in Google and they are the Hall's I use. Also, they are FREE, if you have a couple of spare PC case fans kicking around being useless.
                            I have whole pulse motors running that draw less than 10mA when using such Hall's..their consumption is around 8mA.
                            Neo's can be all North around a rotor or N/S/N/S, virtual Souths are your friend. As the magnet passes, it flips the polarity that the sensor see's (this one anyway). That means that every magnet will fire the sensor

                            You can get good experiment neo's from CD-Rom laser assemblies and much bigger ones from within hard drives. For the bigger ones, bend the metal they are on back with pliers and they will come off. They are flat and usually around at least N40 strength. Long thin ones can be scored across their middles on each side and then will break cleanly. That gives you squared magnets with N on one face and S on the reverse X 2
                            Thanks Slider, i have had a lot of fun tonight with this build I tried a hall sensor from a pc fan and it worked nice with the half sequential bipolar circuit. Got it down to 80ma. I wasn't happy with that so i went back to the full sequential bipolar circuit and this time i put 4.7k resistors on the triggers. I spun the wheel and nothing happened. Done it again harder and it started chirping then it took off. I added another 2k and it reached 1208 rpm drawing 30ma.

                            I have another question, should the the thickness of the bunch of wires be less than the width of the magnet or does it not matter so much?

                            Comment


                            • #15
                              Ah, dleighted that worked out for ya


                              As to the wire problem, others will know a lot more than I. I'd try a smaller and a larger coil and see which is most efficient of the 3..and go from there.

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