F.B.D.I.S.S.M - Flux.Boosted.Dual.Induction.Split.Spiral.Motor.

[Honk]

The motor worked the best (per input ratio) when the operation of the electromagnet was asymmetrical both in timing & field strength,
so giving a greater pull for more time, and a smaller push for less. This may or may not be true in a real motor, however I found it interesting.

Thank you Gregory for doing the simulation. This proves my own observations in the last couple of days.
For once the sim and real world is confirming each other.

While playing around with my setup I noticed the asymmetrical behavior and I made some changes to the controller to make it more flexible.
Now it can be switched between high currents in attract mode and a lower current level for the repel mode or vice versa.
I strongly believe this will boost solenoid efficiency and help me to find the sweet spot.

I have began prepairing the Mumetal samples I got for testing. I will cut it into pieces to form a magnetic core.
Man, is this 1mm thin mumetal sheet tough to saw... It's like hardened stainless steel. My hands ache.
The pieces will then have to be heat annealed in a special gas environment to get the high permeability properties of the final product.
It will be interesting to see the force difference when using a high quality solenoid core vs the oriented steel Iv'e been using.

Btw, which codec is needed for these simulation files of yours?

[Low-Q]

No I didn't use just one magnet in the first set of tests. Please see quoted text from my earlier message
"1pcs of N45 40x18x20mm representing the larger rotor magnet"

The picture I posted was showing just one rotor magnet, but I did not use this setup in the solenoid tests.
I switched to 20mm thickness (2 magnets on top) before testing any of the various combinations.

Ok, I took back my bad words on that.


I uploaded the simulations in case someone would like to have a look at them.
These simulations cannot be compared to a real world device, only show a rough approximation of the main principle involved.

I found that in these sims, the sticky spot appears not exactly at the end of the spiral, but some degrees before. And because of this, the motor worked the best (per input ratio) when the operation of the electromagnet was asymmetrical both in timing & field strength, so giving a greater pull for more time, and a smaller push for less. This may or may not be true in a real motor, however I found it interesting.

I would be interested to know about the differences regarding these things, when compared to an operating real world model of the motor.

Have a Good work!

You're right about the sticky spot. At the end, the magnetic lines finds its shortest way to the oposite pole, so there is in fact a strong counterforce at the very end of the magnet array. In the same way, it requires energy for the rotormagnet to enter the statormagnet again for a new turn. Sounds untrue, but as the magnetic fields at the end of a magnet array is going the oposite direction, there will be some repelling forces right there. This repelling forces will adds up to zero as there is the same effect after the magnet arrays end, where the rotor magnet will exit. So left, you have the solenoid and a sum of pure attraction.
I wouldn't bet a cent, but I like to believe Honk have something good going on here. Looking forward to see the results.

Vidar

[Gregory]

Honk,

download this: http://www.design-simulation.com/WM2D/documents/wmdemo.exe
or this one: http://rapidshare.com/files/85555662/Wm.zip.html
to open the simulations.

I have began prepairing the Mumetal samples I got for testing. I will cut it into pieces to form a magnetic core.
Man, is this 1mm thin mumetal sheet tough to saw... It's like hardened stainless steel. My hands ache. 
The pieces will then have to be heat annealed in a special gas environment to get the high permeability properties of the final product.
It will be interesting to see the force difference when using a high quality solenoid core vs the oriented steel Iv'e been using.

Sounds like a good piece of Man's work.

[Gregory]

You're right about the sticky spot. At the end, the magnetic lines finds its shortest way to the oposite pole, so there is in fact a strong counterforce at the very end of the magnet array. In the same way, it requires energy for the rotormagnet to enter the statormagnet again for a new turn.

Of course, I know I am right. I just wanted to see how much time it takes to get a reply on the mentioned things!

With other words, thanks for your reply & confirmation!

[Gregory]

Here is the formula to control the "electromagnet":

IF ((And ( body[152].p.x < 0 , and ( body[152].p.y < 4 , body[152].p.y > -12.5 ) )), IF(Sign(body[152].p.y / 18) < 0, -6.5, 2.5) , 0)

I attached an image to make it easier to understand what is for what.