Zero Force Motor Replication Project

[Aaron Murakami]

Dmann and others,

I do not know the specific material specifications for the 3D plastic, however I will caution you on the the forces developed by the Neo's weight at high RPM's. The AL rotor was initially designed to retain the the Neo's easily up to 15,000 RPM and more. The 3/4"Dx3/8"T Neo's will produce a radial force of ~320 lbs each at that RPM - if the Neo's are increased in size to the 3/4" square/cube configuration for the given motor rotor of 2.5"D, well you better figure that each Neo is waiting to be launched with about 700 lbs. of force.

So a word of caution is expressed here in that the RPM should be limited by starting out at a low input voltage of 12v and slowly working your way up. It is a given fact that increasing the power of the Neo's will increase the RPM for a given input voltage. This was observed when the AL rotor Neo's were increased from 1/4"T to 3/8"T and the grade from N40 to N52.

It would not be surprising to see the ZFM accelerate at maximum voltage to well over 15000 RPM and much more with the larger Neo's. Be aware that the centrifugal force here is a function of the square of the velocity (RPM).

Tread carefully and test responsibly - we still be in no man's land,
Yaro

I think it would be impressive if the plastic rotor can go over 3-4000 rpm. Has anyone built a small plastic one yet that has posted speed results?

[Yaro1776]

The new rotor is listed with 3/4" X 3/4" slots. [ATTACH=CONFIG]6157[/ATTACH]
I had to add some meat on the bottom to hold it together good. You can see in the pic that the 3/4" squared slot left only a little room for plastic in spots.

Mann

Dmann and others,

I do not know the specific material specifications for the 3D plastic, however I will caution you on the the forces developed by the Neo's weight at high RPM's. The AL rotor was initially designed to retain the the Neo's easily up to 15,000 RPM and more. The 3/4"Dx3/8"T Neo's will produce a radial force of ~320 lbs each at that RPM - if the Neo's are increased in size to the 3/4" square/cube configuration for the given motor rotor of 2.5"D, well you better figure that each Neo is waiting to be launched with about 700 lbs. of force.

So a word of caution is expressed here in that the RPM should be limited by starting out at a low input voltage of 12v and slowly working your way up. It is a given fact that increasing the power of the Neo's will increase the RPM for a given input voltage. This was observed when the AL rotor Neo's were increased from 1/4"T to 3/8"T and the grade from N40 to N52.

It would not be surprising to see the ZFM accelerate at maximum voltage to well over 15000 RPM and much more with the larger Neo's. Be aware that the centrifugal force here is a function of the square of the velocity (RPM).

Tread carefully and test responsibly - we still be in no man's land,
Yaro

[DMANN]

The only reason to add the iron is if there is a desire to replicate what John was actually doing. He didn't in some of the plastic ZFM, but those were also to just demo the principle and were not full replications of his real ZFM designs.

Yaro has shown incredible results with Aluminum so possibly John's original thinking on the ZFM was not completely correct. It definitely isn't the only way the motor will run. Iron would be heavier and would give a better flywheel effect - the aluminum would be lighter and dragged down a bit by the field from the coils, but apparently not that much according to what Yaro has already shared with us all.

I just saw that your rotor is 2.5" diameter.

If you use a square magnet 3/4 x 3/4 by 1/4 thick, you'd get more magnetism into the same slot compared to a disc magnet - about 20% more if they're the same N rating: http://www.magnet4less.com/product_i...products_id=29

If you can make a 3/4 x 3/4 slot, then everyone could either put a full size magnet in there or maybe half magnet and half iron - the slot could be used both ways to compare.

Here are N52 3/4 cubes: http://www.magnet4less.com/product_i...oducts_id=1010 with 76 pounds of pull on each one. If they're 3/4 x 3/4 discs, they'll probably be 63 pounds of pull ballpark.

The new rotor is listed with 3/4" X 3/4" slots.
I had to add some meat on the bottom to hold it together good. You can see in the pic that the 3/4" squared slot left only a little room for plastic in spots.

Mann

[DMANN]

[QUOTE If you can make a 3/4 x 3/4 slot, then everyone could either put a full size magnet in there or maybe half magnet and half iron - the slot could be used both ways to compare.[/QUOTE]

That is what I will do. I may be able to do it first thing Sunday morning est.

I have my designs set at +.009" to fit mags, shaft, bolts bolts, etc....on my machine. That equates to +.2286 mm.
This does not seem to be an issue for anyone? I have not had any feedback on the prints. Feedback will help me.

You may be able to fit larger magnets in the magnetic levitation supports if needed. That is if you are having lag issues. Also, for simplification, Maget4less has 2" ring magnets with 1/4" center holes. This may alleviate some balance issues. You could just slide and glue collets to each side of the magnet to keep it in place. Of course the down fall would be the permanence created.

Thanks
Mann

[Aaron Murakami]

I'm thinking 5/8" round stock. I can expand the magnet set screw hole up to 5/8" to be used for the iron piece. Another option would be just to make a slot for a bigger magnet. A 3/4" X 3/4" cylinder magnet would fit. I can design whatever just let me know. It will be Monday night before I will be able to do anything. If you draw a design on paper and post a pic, I can see what you are describing. If everyone agrees on the "T" I will do that, but understand that you will only be able to fit about a 3/4" X 1/2" piece of iron in that spot.

Mann

The only reason to add the iron is if there is a desire to replicate what John was actually doing. He didn't in some of the plastic ZFM, but those were also to just demo the principle and were not full replications of his real ZFM designs.

Yaro has shown incredible results with Aluminum so possibly John's original thinking on the ZFM was not completely correct. It definitely isn't the only way the motor will run. Iron would be heavier and would give a better flywheel effect - the aluminum would be lighter and dragged down a bit by the field from the coils, but apparently not that much according to what Yaro has already shared with us all.

I just saw that your rotor is 2.5" diameter.

If you use a square magnet 3/4 x 3/4 by 1/4 thick, you'd get more magnetism into the same slot compared to a disc magnet - about 20% more if they're the same N rating: http://www.magnet4less.com/product_i...products_id=29

If you can make a 3/4 x 3/4 slot, then everyone could either put a full size magnet in there or maybe half magnet and half iron - the slot could be used both ways to compare.

Here are N52 3/4 cubes: http://www.magnet4less.com/product_i...oducts_id=1010 with 76 pounds of pull on each one. If they're 3/4 x 3/4 discs, they'll probably be 63 pounds of pull ballpark.

[DMANN]

Readily available square key stock from the usual suppliers (McMaster, Grainger, etc) that will work...
Yaro

I'm thinking 5/8" round stock. I can expand the magnet set screw hole up to 5/8" to be used for the iron piece. Another option would be just to make a slot for a bigger magnet. A 3/4" X 3/4" cylinder magnet would fit. I can design whatever just let me know. It will be Monday night before I will be able to do anything. If you draw a design on paper and post a pic, I can see what you are describing. If everyone agrees on the "T" I will do that, but understand that you will only be able to fit about a 3/4" X 1/2" piece of iron in that spot.

Mann

[Yaro1776]

What you just drew there is interesting - those inside magnets might actually retain the flux like an iron keeper since it pulls in the bottom facing field of the outside magnets, which is part of the point to the keeper. But not sure of how some of the coil flux will be diverted through the rotor.

Of course like I mentioned, not sure if there are standard size little iron stock pieces that can be inserted into some standard sized slot. Maybe stacks of washers or something as long as they're magnetic.

Readily available square key stock from the usual suppliers (McMaster, Grainger, etc) that will work...
Yaro

[Aaron Murakami]

Can you illustrate what you are describing? This is what I was thinking and what I did on the Window Motor rotor.

What you just drew there is interesting - those inside magnets might actually retain the flux like an iron keeper since it pulls in the bottom facing field of the outside magnets, which is part of the point to the keeper. But not sure of how some of the coil flux will be diverted through the rotor.

Here is what I was meaning:



Of course like I mentioned, not sure if there are standard size little iron stock pieces that can be inserted into some standard sized slot. Maybe stacks of washers or something as long as they're magnetic.

[DMANN]

Hi Mann,

That's almost it - if you lave the magnet holes like that, but rotate the keeper holes 45 degrees so they actually make a T with the magnets, then the iron pieces will literally hold the magnet field from the magnet face on the axle side. I don't know if there are simple iron pieces of standard sizes that can be put in but this is the idea anyway. The model Peter built had the square iron with magnets on each of the 4 sides and Bedini's original ZFM's all had an iron keeper with 2 magnets 180 degrees from each other, but in all cases, the magnets were intended to have an iron keeper. Although in the 3D print idea, the axle end of the magnet keepers won't physically touch, they're still providing a path for the magnetic flux.

Can you illustrate what you are describing? This is what I was thinking and what I did on the Window Motor rotor.

[Aaron Murakami]

I added this revised ZFM rotor to the file. It is a bit more complex. But I think it will give you what you are looking for. Thanks for the suggestions.

http://www.magnet4less.com/product_i...oducts_id=1023
or
http://www.magnet4less.com/product_i...oducts_id=1264

Both will take a #6 bolt. I made the hole toward the shaft .6" so a .5" long bolt should work.
Added the slots for balancing. They will fit the .75" X .25" mags as well if you want to experiment with that.

Enjoy
Mann

Hi Mann,

That's almost it - if you lave the magnet holes like that, but rotate the keeper holes 45 degrees so they actually make a T with the magnets, then the iron pieces will literally hold the magnet field from the magnet face on the axle side. I don't know if there are simple iron pieces of standard sizes that can be put in but this is the idea anyway. The model Peter built had the square iron with magnets on each of the 4 sides and Bedini's original ZFM's all had an iron keeper with 2 magnets 180 degrees from each other, but in all cases, the magnets were intended to have an iron keeper. Although in the 3D print idea, the axle end of the magnet keepers won't physically touch, they're still providing a path for the magnetic flux.

[Deuis]

Hi AlvaroHN,

There is a product I use here in Australia, its glue lined heatshrink.
It wont be see through, but it will certainly hold what you want into place.
Depending where you buy it from it has various sizes and wall thicknesses.
Slip it over your rotor, heat with heat gun and the heatshrink pushes the glue around while it shrinks.
This stuff is tough as nails.

https://www.voltexelectrical.com.au/...at-Shrink.aspx

I am always afraid of flying magnets, on my machine which has a small rotor 10 cm diameter, 3,9 inches diameter, what I have is a plastic circle around the rotor, I cutted a strip of a coca cola large bottle, and then placed it on the rotor all around, then with a lighter from below I gave it a little heat so the plastic shrinks to the rotor size.

[DMANN]

I added this revised ZFM rotor to the file. It is a bit more complex. But I think it will give you what you are looking for. Thanks for the suggestions.

http://www.magnet4less.com/product_i...oducts_id=1023
or
http://www.magnet4less.com/product_i...oducts_id=1264

Both will take a #6 bolt. I made the hole toward the shaft .6" so a .5" long bolt should work.
Added the slots for balancing. They will fit the .75" X .25" mags as well if you want to experiment with that.

Enjoy
Mann

[AlvaroHN]

I am always afraid of flying magnets, on my machine which has a small rotor 10 cm diameter, 3,9 inches diameter, what I have is a plastic circle around the rotor, I cutted a strip of a coca cola large bottle, and then placed it on the rotor all around, then with a lighter from below I gave it a little heat so the plastic shrinks to the rotor size.

[Aaron Murakami]

Hey Yaro. A light amount of high expansion glue such as original gorrila glue should work just fine. I don't use anything though. It is a tight fit with my print settings.

Mann

Those are great - what about some cutouts in the rotor to insert iron slugs? The way you have the slot of the magnet, if you made a T where the perpendicular cutout goes from the magnet towards the shaft, it would perform as an iron keeper, which is what John always used. It would also add a bit more weight to the rotor for some flywheel effect.

@All, might find that coils that are longer than 90 degrees might wind up being optimum. If it is for producing more torque, power would be on longer but is required to push/pull the rotor for longer. I have no idea if anything other than 90 degrees would work well or not but is worth asking the question.

[DMANN]

Hey Yaro. A light amount of high expansion glue such as original gorrila glue should work just fine. I don't use anything though. It is a tight fit with my print settings.

Mann