JB Zero Force Motor - anyone building?

[tinman]

Yeah but you didn't give it a cool name. Dig up the vhs tapes and put it on YT otherwise it's not real
I'm not that impressed with a 5ma current draw as lid motor reported. Geez even I can get a pulse motor running at 6000 rpm on 5ma

well i just had to go and build one Jim lol.

Video up soon-->what a crap motor lol.

[minoly]

Lidmotor's latest "Zero Force Bedini":

https://www.youtube.com/watch?v=n6h5kK8zUog

The timing on that build is still wrong - Have to watch JB's vid and slow it down frame by frame.
I was able to get my toroidal build down to microAmps. Still, I have many a build that will run on low watts like that including the "dollar store solar begging cat"
https://www.youtube.com/watch?v=oDiaiKzWx2Q
In his video JB actually states where the timing is as well.

[Lidmotor]

 I am most anxious to see detailed plans and videos showing how this motor can run on micro amps and produce torque.  I must be missing something.  I just see a curious inefficient motor. 
  Tk I would really like to see that 'slab motor' in action.  That might be my next fun build.
--Lidmotor

[MileHigh]

In Lidmotor's clip you can see that he has the reed switch positioned so that the drive coils are energized when the rotor magnets are approximately in the middle of the drive coils.  This is what JB stipulates so I am not sure why you have an issue with the timing.  We can't see the duty cycle.

In the JB clip there is a double-pulse that energizes the coils.  That seems strange considering he is using magnets and (presumably) a single reed switch on a timing wheel.  It would be worth investigating if you has his build.  Assume the rotor magnets are approximately in the middle of the drive coils when the drive coils are energized.  We can see the duty cycle is about 40% ON time.  I am going to guess that that's too high a duty cycle and he is wasting energy.  However, because of the way his timing wheel and the magnets and reed switch are arranged, he can't really move the reed switch in and out and adjust the duty cycle easily.

For your build, if you make a full toroidal core with no air gaps then it's very likely that the motor won't run at all.  Almost all of the flux will be contained in the core and none will be available to provide attraction/repulsion to the rotor magnets.  It looks like the reason it runs is because you are "saved" by the little white plastic gaps at the top and (presumably) bottom of the two halves of the core.  It goes right back to the main problem with this design, you are getting very little bang for your buck when it comes to using the available magnetic energy that you put in the drive coils.  I will post a superior design that makes use of more of the energy that you put in the drive coils.

I think that Lidmotor is paying lip service to JB when he says, "this point in a magnet where the flux goes to zero" and he is pointing at the center of one of the drive coils.  He is fully aware that the flux does not go to zero at the center and there is no Bloch wall at the center of a magnet or at the center of an energized coil.  That's a foolish myth that needs to be corrected.

[MileHigh]

Well here is the kick-ass pulse motor that I am calling the "figure-eight" pulse motor.  It uses both ends of the drive coil, and there is a pair of drive coils, hence the "figure-eight."

The drive coils I made have a "C" form, but that's just because I was using Paint and I can't be bothered to do anything fancier than that.  They could just as easily be nice smooth curves if you wanted.

Since this motor is using both ends of a pair of drive coils, and if you went with full pull-then-push double pulses, it would be a screamer and use a fair chunk of the energy that you put into the drive coils to actually make the rotor turn.  With pull-then-push timing you can energize the pair of drive cols eight times per revolution.  Considering that there are four sources of driving torque on the rotor, that's almost like having thirty-two "pulses per revolution."  However, the timing here is very tricky, because if you are going to fire the drive coils every 1/4 turn, then you have to alternate the polarities for energizing the coils every 1/4 turn.  That requires some sophistication in the timing and coil energizing circuit.  The easiest way to get the design going would be to fire the drive coils every 1/2 turn.  Then you can forget about the alternating polarities business.

The main design and build challenge is developing a system to implement the pulse timing.  You could use a "dumb" pick-up coil that is coaxial with one of the ends of one of the drive coils a la standard Bedini SG motor.  But then you are a victim of the double-pulse problem because when the drive coil energizes it feeds back into the pick-up coil and switches the transistor off.  Then the transistor switches on again and so on.  You have limited control over the pulse timing with that solution.  The MHOP design is not really going to work either because you don't have a "clear" space to add the sensor coil for the op-amp that is aligned in time with where you want to energize the drive coils.

To solve the problems associated with the timing circuit when you want to fire the pair of drive coils four times per revolution, you can see how I added four "button" magnets that are 45 degrees away from the main rotor magnets.  They also alternate north-south to be in accord with the way the rotor magnets are arranged.  If you put only two button magnets instead of four, the you can use a "dumb" pick-up coil or a "dumb" reed switch or the basic MHOP circuit to control the firing of the drive coils only twice per revolution.  You still will have quite a bit of control over the timing because you can move the pick-up coil or the reed switch, play with the value of the base resistor, etc.  If you want much better timing control and sharp ON-OFF switching, use the MHOP timing circuit and then you are laughing.  One of the biggest advantages of the MHOP design is the razor-sharp ON-OFF switching.

With four button magnets and the MHOP timing circuit, then you can have a very flexible control for the timing of the energizing pulses.  However, you still have the problem of making sure that you are in sync with the north-south-north-south arrangement of the rotor magnets.  Since the button magnets alternate north-south in theory you have all of the information you need to know which direction to energize the drive coils every 1/4 turn.  However, the devil would be in the details.  For example, you could use a CMOS 4000 series Set-Reset Flip-Flop to get the sequencing of the energizing of the drive coils properly synchronized with the rotor magnets.

The "Cadillac" design would fire the rotor eight times per revolution, with the fancy alternating polarities and the pull-push on the rotor, and also have full pulse timing flexibility like the MHOP design.  It would be a real challenge for the average experimenter to design and build, but that's supposed to be part of the fun.