Electric Motor Secrets

[Peter Lindemann]

Perhaps!

Yes Peter
Now I know that
Thanks.
I have been thinking about the switching circuit of this motor. I recently watched again a video that Steven (nali2001) posted many posts ago with his core tests. In his tests he used different core materials and found out that the usual transformer cores retain residual magnetism if some DC pulses are used to create a magnetic field. In the attraction motor we have only DC pulses and the same magnetic poles on each pulse. It could be that because of this, the stator cores are not demagnetizing fully and this reduces the efficiency. So maybe for the new version we should develop a circuit that changes the polarity of the current flow on each pulse, so that in one pulse there is an N pole created and on the next pulse there is an S pole and so on. What do you think about that? Shouldn't bee too hard to modify the circuit to achieve this, right?
Thank you,
Jetijs

Jetijs,

High quality transformer laminations de-magnetize completely, so the problem (if it arises) is a matter of materials. IF the effect shows up, you can certainly try what you are proposing as a remedy, but I would think it will not be necessary. Your experimental results will tell the truth.

It is always good to be thinking ahead, but don't act on it until REALITY tells you it is necessary.

Peter

[Mark]

Most impressive work Jetijs! I am looking forward to hearing more after you get it running. Excellent work!

[Jetijs]

Yes Peter
Now I know that
Thanks.
I have been thinking about the switching circuit of this motor. I recently watched again a video that Steven (nali2001) posted many posts ago with his core tests. In his tests he used different core materials and found out that the usual transformer cores retain residual magnetism if some DC pulses are used to create a magnetic field. In the attraction motor we have only DC pulses and the same magnetic poles on each pulse. It could be that because of this, the stator cores are not demagnetizing fully and this reduces the efficiency. So maybe for the new version we should develop a circuit that changes the polarity of the current flow on each pulse, so that in one pulse there is an N pole created and on the next pulse there is an S pole and so on. What do you think about that? Shouldn't bee too hard to modify the circuit to achieve this, right?
Thank you,
Jetijs

[Peter Lindemann]

Awesome, as usual!

Jetijs,

Awesome work. Don't forget to take a little time to relax and enjoy "not doing" during the Holidays. Relaxation is the Key to Higher Perception... you know.

Best wishes always,

Peter

[Jetijs]

Hi aladinlamp
The rotors are pressfitted on the shaft with some bearing glue between the rotor and shaft, should work great.

BTW, a little update. I have finisged my motor endplates. Now I just need to get the bearings, make four bearing holders and wind the coils

[aladinlamp]

Hi Jetijs
how will be your rotors attached to the shaft?
thanx

[Jetijs]

Thanks Ren

[ren]

super nice JET

Love your work. Those coils came up a treat. Im rebuilding the window motor and pre fab'd coils like that is what I am going to do. Make for easy removal and testing etc. The resin is a great idea too.

I like your train of thought with the two rotors coupled together on the same shaft being out of phase with each other.

Keep up the good work

[Jetijs]

Look at previous posts in this thread. I am making two separate motors with shafts coupled together and offset timing for each motor so that when one motor rests and moves only with the inertial force, other motor switches ON and takes over the load. So that there is no inertial movement and the system operates at 100% ON time. Should give some very good results

[broli]

Looks very nice indeed. I also didn't know you were making two. Are they part of the same system or are you going to make two separate motors?

[Jetijs]

Got my Christmas present early this year. I found a guy who was willing to do all the lathe work before holiday season. All the parts that I could not do by myself are now done. Tried the prewound coils on the stator - works very well. This is great because I will have something to do during the long holiday season



Thank you and Merry Christmas to you all!

Jetijs

[Jetijs]

Hi all
Here's my first attempt of prewinding coils. At first I built a block from acrylic that is exactly the shape of my stator poles. There is a hole drilled through the block so that I can bolt two end plates to that block that will hold the wire from the sides. Now I wrapped a piece of baking paper around the core, because nothing sticks to this stuff. I put the end of the bolt in a lathe and set it to rotate at the slowest possible speed. I pulled the wire hard in the winding process so that the windings get as dense as possible. When the first layer was wound, I covered it with some epoxy resin (the kind that is used in gluing glass fiber). Then I wound the next layer backwards and again covered it with epoxy. I wound five layers this way. When the 5 layers were done, I put another layer of epoxy on them and let it cure. After that I just unscrewed the bolt, removed the end plates with some gentle hitting and pushed the core piece out. I used 1.3mm thick wire for this test coil. I calculated, that 5 layers should make the coil "wall thickness" exactly what I need to be able to slide the coil on the core. Unfortunately a wire this thick does not bend too good and the wall thickness became bigger. But this was just a test run to see how this works and if I will be able to wind it properly when the time comes. Works good. But I will need to use a smaller gauge wire. I think 0.9mm wire should be fine.
Here are some pictures:




Edit: I made another test coil using 0.7mm thick wire, this is almost 2x smaller wire diameter than with previous coil. This time it was a lot easier to wind the coil and everything came out much better. My calculations show that with 0.7mm wire I can wind about 100 windings till all of the allowed coil area is filled. That makes about 50 turns of bifilary wound coil. In this case each of the coils will have about 1Ohm of resistance.


Anyway, this is a great way to make prewound coils, it is a LOT easier than winding the coil on the stator directly and you can do this alone without any help from others.
Thanks,
Jetijs

[Beshires1]

Is it possible to contrive an arrangement which causes the rotor to always accelerate in one direction without an intelligent circuit?

Honestly I don't think you can with an all metal, Iron armature. Basically its because your creating a magnet to metal attraction. when ever a coil is pulsed the iron will go to the closest magnet field be it forward or backward. When you run a magnet over a piece of iron that is relatively the same shape of the magnet, the iron will jump to the magnet and stick, usually on the edge of the magnet. because the attraction will grab the iron before it centers the magnet. That is why I think the iron armature should be round this will rotate the shaft to the closest point of contact, at which time the magnet turns off. The timing controller could be reed switches or hall effect.

[Necchi]

...most electric motors have a odd number of poles between the stator and armature. So that its impossible to have these "dead "spots. In case you missed it back up in this thread and look at the design I posted This addresses this issue. Especially if you want to build a self-starter.

Is it possible to contrive an arrangement which causes the rotor to always accelerate in one direction without an intelligent circuit?

[Beshires1]

Necchi, I see another problem with your design. Lets suppose the rotor is turned so that the stator pole is between two rotor poles. If you apply the power to the coils now, it will try to go both ways as the attraction will be equal to both rotor poles.

Yes this is true but... Its also true that if yours stops with the rotor aligned up with two stator poles it will experience lock-up. This is why most electric motors have a odd number of poles between the stator and armature. So that its impossible to have these "dead "spots. In case you missed it back up in this thread and look at the design I posted This addresses this issue. Especially if you want to build a self-starter.