Zero Force Motor Replication Project
JB demonstrated his zero force motor at the recent conference and seemed well a little annoyed that attempted replications on the web have failed, so let's give him a successful replication. I had a chance to examine this motor in depth and ask questions about it at the conference. I will give my take on how it is put together, not why it runs, but how it is put together. That said, unless my eyes were cheated by some spell, it ran and then some at the conference.
I will make ideally a few videos documenting each step along the way as I attempt replication. This is both so if I am wrong it may be pointed out to me and if I am correct others will have a template to work from.
So first off what one notices is you have a toroid which is split in two with no iron magnetic linkage between the two halves. A rotor is placed inside the split toroid with magnets at 0/90/180/270. You have a single wire which is wrapped around both halves of the toroid with equal number of winds on each side. The machine at the conference showed red and green wire on the coils. John explained that there is no trigger winding and Peter explained that the coil wasn't bifilar just different available wire. There was a timing wheel with magnets at 180 degrees which trigger successive reed switches placed 90 degrees apart. The reed switches in turn signal a Bedini/Cole bipolar commutation circuit, this part I believe is key. I haven't reviewed in depth attempts on the internet at replication but did see one where someone had all N facing magnets on the rotor and complained the machine ran poorly. Well, I would think you would not be reversing the polarity of the coil unless the magnets 180 degrees apart from each other are N/S. And as the two halves of the split coil have opposite effects it seems surprising it could run at all as a monopole set-up.
If my above analysis is correct, possibly, (possibly), the most difficult part will be building the H bridge circuit. So the first step will be to order the parts and build the Bedini/Cole bipolar commutator, will probably build at least two or three, that circuit seems to have a lot of uses. First time I tried to build it, it took me a week or two. I am hoping for an hour, afternoon or day or two this time around. Ironically when I first thought about how I might change the SSG (not that I had a great one to start) my thought was why not N/S/N/S magnets, a push/pull arrangement as I now guess it is called. Hey no problem, just need to switch the polarity of the coil when the magnets go from N to S. Kept expecting to find on the internet “Switches for idiots, transistors are switches, relays are switches, here is how to make transistors behave like a SPDT relay”. Never showed up. I must have spent a month on it, I did realize I needed an arrangement of NPN/PNP transistors when it finally occurred to me as Kramer said, “Why don't you just tell me the name of the movie you want to see!” So I asked on energetic forum and within a day or two had the schematic for the Bedini/Cole commutator. As I said still took me a week or so to do the paint by numbers from the diagram, but eventually I had that son of a gun running with hall effects, only to realize the SSG isn't really about torque, more about timing. That said, now I am glad I threw myself at that windmill as the timing issue is the same.
So we need a split toroid, I saw a large toroid at Nebraska Surplus for 60 bucks which I could saw in half, however, half the time I spend money I realize later I could have done it better for free. So my thinking is I have a lot of welding rods, I will cut them to size then bend them around a CD casing and glue or tape them together. After winding the coils use some rubber washers as spacers to put the two halves together. I can then use CDs glued together as the rotor and some neodymiums. Use an empty plastic spool as the timing wheel, after that the only question is the timing which could be done with Hall effects or reeds, not sure which I'll use yet.
This isn't the sort of thing which I will post next week-end, this will likely take a bit of time. The first part will just be building a working Bedini/Cole commutator circuit. I will post video of that when I've done it. I am not looking to be the first here to replicate, just to give it a try. The timing appears to be identical to the window motor which perhaps some/many on this forum have built, the winding appears more simple, by this I mean if any wish to leap frog ahead of me and steal the garland of first web replication that's great, I am just saying let's do this, and if it gets done maybe make something useful with it.
First, the Coils are wound on a piece of PVC/ABS 4" Pipe. Not a Steel core...!!!
2nd, Yaro and I measured the coils resistances, and all dimensions, he took notes and will post them here soon.....
3rd, Tom is working on a 3D printed Stator coil holder and Rotor, etc......
Last edited by RS_; 07-20-2016 at 08:44 PM.
Originally Posted by RS_
Does Tom have a time frame for making the 3D printed Stator holder and Rotor?
I dont know. He printed a stator section at JB's shop before i left, and was working on the rotor, i will print one when he releases the files
Compadres - Paul, RS and James,
Still emerging from my post conference lethargy and have had a number of summer visitors that have slowed down my initiative on the ZFM effort. I will put together all the available data and measurements over the next few days. I will say that this motor , according to sources, has some very unusual characteristics.
One of the items that I noted on the current YouTube replications is that they are being operated with only one reed switch. The existing ZFM from the show has two reed switches 90 degrees apart.
Other details: the rotor magnets are 3/4" neo's 90 degrees apart and that on the working model there are four strands of #20 wire in series wrapped in a figure eight pattern ( correction, coil wrap is regular and magnetic field can be described as figure eight) on the toroid - a bit clueless on my part as to the specifics of this detail.
I do have some good detailed pictures of the assembly and will post in my next com effort. Need a bit of time here to measure all with my CAD.
Thanks Paul for kick starting this effort,
Last edited by Yaro1776; 07-29-2016 at 04:06 PM.
Reason: New info on mag filed
been catching up on orders, making coils is labor intesnsive and does not leave much free time for anything else. I do have a rotor and stator designed. I will send the files as designspark documents to anyone that wants to play with them, they are pretty close to the right sizes. still need to design the side plates, if everyone would download design spark mechanical we could all work cohesivley with ideas and share design files. whan you share an stl file which is only good for slicing engines you cannot play with it and change it. so using an editable file format would help us all. JB uses designspark mechanical.
Last edited by Tom C; 07-22-2016 at 08:24 AM.
experimental Kits, chargers and solar trackers
Hi Folks - RS and Yaro,
I would like to ask some questions on this motor if you could answer. I did not attend the conference.
First is whether this setup was demonstrated on the conference by John:
If yes, then my next question would be on the number of coils. Yaro mentioned four strands of #20 wire in series and member ZPDM wrote this: "You have a single wire which is wrapped around both halves of the toroid with equal number of winds on each side. The machine at the conference showed red and green wire on the coils. John explained that there is no trigger winding and Peter explained that the coil wasn't bifilar just different available wire."
What I can see from the above video there are 4 wires but twice: 4 wires seem to be on left hand side and 4 wires seem to be on the right hand side half-toroidal bobbin. And I assume that the 4 wires constitute 4 coils and these coils are connected in series as Yaro found (both on the left and right hand side bobbins) and finally the resulting series coils (as a "single" coil on both bobbins) are connected in series and driven by the Bedini-Cole sequential bipolar circuit. Is this guessing from me correct?
Finally, was it mentioned how the input current draw changes (if it does at all ) when a mechanical load is exerted on the motor shaft?
Thanks for any clarification. Looking forward seeing some pictures on the setup.
Many Thanks, I did not know that and my build attempt likely would have been quite frustrating, Thx again. RS_ unless I am mistaken you were the one who showed me the Bedini/Cole circuit ... now look what you've done
Originally Posted by RS_
Last edited by ZPDM; 07-22-2016 at 10:10 PM.
Thanks Yaro for your more detailed research into this. Good thing I decided to post before building as it may likely have ended badly.
The first step here is to view JB's video https://www.google.com/url?sa=t&rct=...XoKuGOX0dWzBgA This should give a good representation of the ZFM in operation - more importantly inspect the magnetic field diagram that is in two places. This shows JB's basic concept and layout of how the device works - very helpful.
Detail wise RS and I measured the the significant details using a piece of graph paper as a ruler - Ha! The drive shaft appears to be a nominal 0.375 inch. The toroid is 4 inch plastic pipe sched 40 with an ID of 4.00 inch and 1.25 inch in length. It is notched with two 90 degree cut outs for the coil windings - not able to determine at this time the depth of the notches. The OD of the neo holder is about 2.6 inch. The running gap to the windings appears to be about 0.25 inch with the neo's at about 0.325.
These dimensions should be very close to actual, but bear in mind that they are scaled off the pics (attached).
RS and I measured the wire resistance of each series strand (four wires) at 0.8 ohms, however the overall measurement of the series strand turned out to be 2.5 ohms - scratching my head on this one since it significantly alters the total length of #20 awg mag wire. Each coil had a separate termination block. Somehow we fouled up?
The firing circuit is activated by a timing rotor with two magnet 180 degrees apart triggering 2 reed switches to the circuit. It appears that these magnets are aligned with the rotor neo's. There may be some minor adjustability here for getting the timing right.
Being a gear head the circuit with 4 transistors is pretty much Greek to me. I leave this detail to the experts. See pic. I do have a closeup of the board itself but need to retrieve it from my cell - will post it later in the day.
The physical enclosure is a detail that is not overly important - the guts are the thing.