Can someone confirm this in FEMM?

[robbie47]

@Robbie, The small bottom magnet is supposed to move in and out of the screen and I know this cannot be done in 2d software so down will have to do. When inserting the small magnet back into position it needs to have been shifted over .140" so it again starts out .015" from center line of the top small magnet, but on the other side of center line because now it will be going the other way.

Other wise you are correct.

Lumen,
A trick to simulate the z-direction fade in - fade out could be to gradually weaken the magnetic value to zero. Just a thought....
What are your desired output parameters? Force?

[lumen]

Robbie,
Yes, force. Also, that shift needs to be .155" to get .015" from center line not the .140" I had mentioned.

A fade in and out will discount any force it takes to place the magnet into the setup and it will likely show a lot of gain.

Thanks for doing this, I don't have the script thing down at this point even though I have written a 4 axis CNC control software to operate my machines, it seems like I tend to shy away from learning another programming language.

[robbie47]

A fade in and out will discount any force it takes to place the magnet into the setup and it will likely show a lot of gain.

Yes, you are right. So I will simulate shift in and out in Y-direction as suggested earlier.
It will need to wait until tomorrow. It's getting pretty late here (Holland)

[lumen]

Robbie,
I tested your modified file and the changes you made shifted the optimal position of the lower small magnet.
It now seems the best starting point is at a distance of .025" from the center line of the upper small magnet.
After moving the large magnet .55 to the right, the small lower magnet would then need to have the polarity reversed then moved over -.175" so the opposite side is .025" from the center line of the upper small magnet to reverse the process.

It should not be necessary to simulate the reversal because in theory it should be the same as the first cycle only opposite.

You could use the fade in and out idea, to simulate the lower magnet moving in and out of the screen and this would show the best case condition of the setup. Moving the lower small magnet up into position and then down at the end of the cycle would show the worst case condition. Sliding in and out of the screen should fall somewhere in between these conditions.

[jonifer]

program from femm.foster-miller.net is learning only for study, not realy calculate magnetic force.
Use Femlab from Comsol (3d program) or you can't use seach system on China FTP,