Electric Motor Secrets

[Peter Lindemann]

Smallest Gap, any way you can..!

[QUOTE=Jetijs;8557]Thank's Peter
I will redesign the rotor to the X form and make the air gap thinner. But I think, that I won't be able to make the air gap thiner than maybe 0.5mm, because the tolerance of the laser cutting machine is only 0,15mm. Also the shaft an bearing system must the be very accurate. Or maybe I should cut the X rotor a little bit larger for the startor to fit in and then just machine off the needed thickness with lathe, that way the tolerance of the laser is no longer crucial and I can make the gap even smaller I think, my X type rotor could be about 120mm in diameter so I don't need to redesign the stator core.
Thanks,



Dear Jetijs,

Yes, the new design will work well for you. Your idea of cutting the rotor pieces a little over-sized, and then machining them back on a lathe is the right way to think about it. If the rotor pieces are made of standard motor lamination material, they are very difficult to machine. You will need the hardest ceramic cutting tools in the lathe that you can find. Also, its an "interrupted cut" so the stresses on your rotor can be pretty high. Just take very small cuts, like .001" or less at a time. If you can do this, you should be able to practice a .1mm gap on both sides for a total gap of .2mm. (Also, don't forget, when you take a .001" cut on a lathe, you are taking .001" off the RADIUS, which is actually .002" off the DIAMETER of your material.)

When you get to designing the circuit part, post that here to so I can help you with that as well.

I'm committed to your success. Every mistake we can catch BEFORE you spend any money is cheaper to fix!

Peter

[nali2001]

Core design

Just to drop a design note in:
It also in advantageous to put the coils just at the 'contact' surface.
Like this:
http://home.planet.nl/~sintt000/Core.jpg
By doing that you eliminate a lot of 'travel' for the flux to reach the 'point of action'. Which means far less steel losses, better response and stronger interaction. Also will this slightly lessen the need for sub micron airgap sizes.
Anyway it's only a slight design change but it has 'huge' (relative term) benefits.

Regards,
Steven

[Peter Lindemann]

A slightly different take.....

Just to drop a design note in:
It also in advantageous to put the coils just at the 'contact' surface.
Like this:
http://home.planet.nl/~sintt000/Core.jpg
By doing that you eliminate a lot of 'travel' for the flux to reach the 'point of action'. Which means far less steel losses, better response and stronger interaction. Also will this slightly lessen the need for sub micron airgap sizes.
Anyway it's only a slight design change but it has 'huge' (relative term) benefits.

Regards,
Steven

Steven,

I appreciate your experience in this field, as I know you have built and tested multiple machines in this genera, but my understanding of the benefits of placing the coils right in front of the gaps is slightly different than yours. I do not believe the benefit is due to lowering the steel losses since the total flux going through the steel is the same regardless of coil placement. I believe the benefit is due to lowering the amount of stray flux that might find its way around the coil in the air when the coil is on the back leg. This loss is quite low as soon as the iron piece starts filling the gap for the motoring process to begin. Jetijs has a viable design with the coil on the back leg and this will work well as a first model for him. I used this method with the Flux-Motor in 1983 and it works well.

Also, in my experience, there really is nothing that can compensate for not having the very close air-gaps. The closer the tolerances, the higher the mechanical energy production at no extra running cost. Since "free mechanical energy production" is what this motor project is about, why not go for the max?

Peter

[sykavy]

Steven,

I appreciate your experience in this field, as I know you have built and tested multiple machines in this genera, but my understanding of the benefits of placing the coils right in front of the gaps is slightly different than yours. I do not believe the benefit is due to lowering the steel losses since the total flux going through the steel is the same regardless of coil placement. I believe the benefit is due to lowering the amount of stray flux that might find its way around the coil in the air when the coil is on the back leg. This loss is quite low as soon as the iron piece starts filling the gap for the motoring process to begin. Jetijs has a viable design with the coil on the back leg and this will work well as a first model for him. I used this method with the Flux-Motor in 1983 and it works well.

Also, in my experience, there really is nothing that can compensate for not having the very close air-gaps. The closer the tolerances, the higher the mechanical energy production at no extra running cost. Since "free mechanical energy production" is what this motor project is about, why not go for the max?

Peter

Does it make a difference to taper the iron like you showed in your video on the lip of the solenoid? I thought that less iron made less attraction. Was I wrong?

[Peter Lindemann]

Iron Lip in the Solenoid...

Does it make a difference to taper the iron like you showed in your video on the lip of the solenoid? I thought that less iron made less attraction. Was I wrong?

Sykavy,

In my DVD, the intruding lip of iron inside the solenoid is not necessarily the best design. I used this to illustrate my point that Teal's Magnipulsion Engine used SOME design feature to accomplish a close air-gap alignment at the beginning of his power stroke when the crank was still in mid-stroke. Since making the DVD I have thought of other designs that are even simpler, that accomplish the same thing.

There is nothing magical about tapering the iron. In some designs, it helps shape the magnetic field to produce an advantage. In other designs, it doesn't help at all. These things are best worked out in your test models.

Peter

[Jetijs]

Peter,
just received my parts from the laser cutting guy. Here are some photos:




Here's a close up. You can see that the quality of the cut is very good:




The sheets are 1mm thick. They were cut using O2 gas for cooling. The quality would be greater in they were using N2, but that would be more expensive and the cut with O2 is already almost ideal. The material is not a standard transformer iron, because they did not have such material. This is regular steel with some carbon content. It is magnetic. I made an experiment, I put a strong neodymium magnet on one of the plates, then I removed it and put a small needle on that plate I pulled the needle slowly in the air and noticed, that the plate tends to lift a little bit. That means that the plate became magnetized. I know, that this is not good. What do you think? Will it still work? Is it wise to continue with the construction if this material is used? Or should I start to look for other materials?
Thank you,
Gatis

[Peter Lindemann]

Iron has residual magnetism

Jetijs,

Your motor core parts look excellent. While it is true that the residual magnetism in this steel will reduce the efficiency of the motor, it will still operate. Since this is your first unit, you could still learn a lot by going ahead with what you have. It's a shame to waste the money on the wrong core material, but since the money is already spent......

Its your choice.

Peter

[Jetijs]

Ok, I will carry on, since the core material is the most expensive part of this setup and I already have everything else. I will cover the plates with a thin layer of varnish to isolate them form each other. Then I will screw the parts together and do a little lathe work to get the rotor a correct spacing.
As you said, I will at least learn a lot
I will inform you about my success.

EDIT: I am glad to tell you, that it was a false alarm with that rotor material magnetizing. Turns out, that not the rotor plate remained magnetized, but the iron needle. I tried this test again with more needles and this time I did not allow the needle to interact with the magnet directly, only with the rotor plate That's a big relief for me, I have even considered to heat treat the plates to change the material properties, but now I wont need to do that

Thank you,
Gatis

[Peter Lindemann]

Good News

Ok, I will carry on, since the core material is the most expensive part of this setup and I already have everything else. I will cover the plates with a thin layer of varnish to isolate them form each other. Then I will screw the parts together and do a little lathe work to get the rotor a correct spacing.
As you said, I will at least learn a lot
I will inform you about my success.

EDIT: I am glad to tell you, that it was a false alarm with that rotor material magnetizing. Turns out, that not the rotor plate remained magnetized, but the iron needle. I tried this test again with more needles and this time I did not allow the needle to interact with the magnet directly, only with the rotor plate That's a big relief for me, I have even considered to heat treat the plates to change the material properties, but now I wont need to do that

Thank you,
Gatis

Jetijs,

Good news that your iron pieces release their magnetism completely. When you are ready, I'd love to see your plans for the circuit.

Peter

[Jetijs]

Peter, I am not ready for the circuit now. I will first put all the mechanical stuff together I have come up with such a design:






The shaft will be made of stainless steel and will be supported by two bearings. The long distance between bearings is to minimize the wobling of the rotor that is caused by inaccuracies in bearings. Each bearing will be put between two aluminum holders. I think I will make the base plate out of hard laminated plywood. The dark cylinders are spacers, that hold the startor in exact same height as the rotor. By adding or removing washers on the distancers it will be possible to adjust the height. I think that I wont have any problems in making these parts with my homemade cnc machine. I already have some experience in building a similar device with magnets as my Bedini SSG, here's a picture:
http://www.bildez.lv/bildes/jetijs/v...1187211446.jpg
http://www.bildez.lv/bildes/jetijs/v...1187211881.jpg

Please tell me what you think. Maybe you have some suggestions?
I am sorry about my english in specific terms, I'm from Latvia.
Thank's,
Gatis

[Peter Lindemann]

Potential Problems.....

Peter, I am not ready for the circuit now. I will first put all the mechanical stuff together I have come up with such a design:

The shaft will be made of stainless steel and will be supported by two bearings. The long distance between bearings is to minimize the wobling of the rotor that is caused by inaccuracies in bearings. Each bearing will be put between two aluminum holders. I think I will make the base plate out of hard laminated plywood. The dark cylinders are spacers, that hold the startor in exact same height as the rotor. By adding or removing washers on the distancers it will be possible to adjust the height. I think that I wont have any problems in making these parts with my homemade cnc machine. I already have some experience in building a similar device with magnets as my Bedini SSG, here's a picture:
http://www.bildez.lv/bildes/jetijs/v...1187211446.jpg
http://www.bildez.lv/bildes/jetijs/v...1187211881.jpg

Please tell me what you think. Maybe you have some suggestions?
I am sorry about my english in specific terms, I'm from Latvia.
Thank's,
Gatis

Jetijs,

The idea of mounting the rotor on a block with bearings that won't wobble is excellent and necessary to hold the systems close air-gap. However, supporting the iron core up on thin mounting posts, especially right next to the rotor interface, will not be able to resist the hundreds of pounds of magnetic attraction across the gap! This stator mount method will fail, for sure.

Each side of the stator interface to the rotor should be mounted firmly on a block of thick plastic that bolts firmly to the base plate. When the coil magnetizes the core, the stator pieces that face the rotor must not be able to move AT ALL!!! Don't assume that the shape of the iron stator will not de-form under the extreme magnetic attraction forces present.

This part of your frame design MUST be reconsidered.

Peter

[Jetijs]

Thank's Peter
You are right, I have not considered that factor and will redesign that frame part. As you said, I assumed, that the thick iron startor piece wont deform.
EDIT:
Ok Peter,
what about this design:



I reduced the lenght of the spacers and increased their diameter. Also I lowered the rotor/bearing assembly closer to the base plate. I think, that such thick distancers will do better than those thin ones in previous design. And if the nuts on the leadscrew through the distancers are screwed on very tight, then I think there should be no problems at all with the startor movement. The use of distancers also gives space for the coil. Is that ok or still not too good? Because I have some other ideas as well

Thank you,
Gatis

[Peter Lindemann]

Much Better!

Thank's Peter
You are right, I have not considered that factor and will redesign that frame part. As you said, I assumed, that the thick iron startor piece wont deform.
EDIT:
Ok Peter,

I reduced the lenght of the spacers and increased their diameter. Also I lowered the rotor/bearing assembly closer to the base plate. I think, that such thick distancers will do better than those thin ones in previous design. And if the nuts on the leadscrew through the distancers are screwed on very tight, then I think there should be no problems at all with the startor movement. The use of distancers also gives space for the coil. Is that ok or still not too good? Because I have some other ideas as well

Thank you,
Gatis

Jetijs,

Much better. This will probably work. What I was thinking of would be even stronger. My suggestion is to produce larger, square blocks of plastic that bolt to the base plate. Then, machine a slot in the top of the plastic mount plates that the iron sections fit into. Then top that with another plastic piece that clamps down on the top of the iron and screws into the plastic block. This leaves no room for movement. All of the stress is at the rotor/stator interface, so these plastic blocks only need to be out at the ends, still leaving an open space for your coil on the central leg. What do you think of this idea?

Peter

[bmind]

Thank you Peter

First I would like to thank Peter Lindemann for releasing the DVD. I saw about 45 minutes last night and got me very excited. I can not wait to go back home and finish it. I am very interested in magnetics and am reading whatever I can get my hands on. I have decided to build a motor with circuit of Peter suggestion posted on "Rotary Attraction Motor". Peter, I would really appreciate if you can tell me which materials (for rotor/motor) would be best suited for maximum torque? In the design you mention Iron. Since there are different types of Iron; is there specific requirements (for Iron) to achieve the maximum torque? I am an engineer and have access to machines that can hold tolerances up to 0.05mm (per side). I really wanted to test some of this theory to get a better understanding of magnetics.
Peter release of this DVD should be applauded. I understand the claims of some people that have worked on this and I agree with them. But I still think that the right thing to do is to give people the knowledge and not let it die with you. Get people excited, together we can achieve much more then individually could ever have hoped for.

[adam ant]

i just aquired a VERY old AC motor(pre 1940's, cloth covered wire) that has a layout almost identical to Mr. Lindemanns except instead of a "X" rotor it has a cylinder. the stator is almost the same, and even the coil is placed in the same spot.

another difference is that the iron stator "arms" completely surrounds the rotor.

what advantage is there of an "X" over a cylinder? i would assume that a cylinder would have a more constant turn.

the reason i ask, is because i was considering having the rotor machined into an "X", and the closed part of the stator trimmed a bit, but i wanted to confirm with Mr. Lindemann before i alter this motor.


Jetijs, i hope you dont mind, i used you pic to illustrate the motor i have.
here is the picture



if this is not better, then i will cut the yellow and blue sections away. and rewind the coil. actually, rewinding the coil the way it is is extremely hard. i would have to feed the wire through the small opening for every single wind.

thoughts??

-bryan