Zero Force Motor Replication Project

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,
Yaro

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.

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Zero Force Motor Replication Project

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