Quote from: bistander on May 14, 2023, 04:23:47 PM
Hi Drak,

Re: 3 to 4 magnets. On surface one might think this will increase flux, and therefore force, by 33%. Fallacy. Doesn't work that way. Yes, there is benefit, but not as you might expect. Without going into theory detail, which a textbook would serve you better than I, do this. Use. This magnetic calculator.
https://www.kjmagnetics.com/calculator.asp?calcType=block
Use N42. I sample ran 0.25 x 0.25 x 0.75 thick & 0.025 inch gap vs same only 1.0 inch thick. Not much difference in pull force at all.

Change the face area, like 0.25 x 0.5 x 0.75" thick and see the difference.

Like they say at the race track, run what you brung. Modify later.
bi

ps. It was likely the bearing seals removed.  And likely they were greased. Especially if you may have contaminated them, clean/flush with solvent to remove all grease and lubricate with light oil, not wd40. Occasionally add a drop of oil. Keep clean, perhaps fashion paper non contact shields.

Thanks, thats a relief, I 'm glad it won't make much of a difference. I'll run all the tests I can with what I got and modify as I go. These bearings are in good condition not contaminated or anything, I haven't removed the seals yet, all of the sanding waste would make its way in them, as soon as it all fits together and spins nicely and the.. device.. is all cleaned out, then I'll remove the seals. I've removed the grease before on other bearings, I replaced with 3-in-one oil, unless there is another easy to get off the shelf product. I'm guessing just for a few tests it should be ok.

If you watch the graphs that show the input torque to output torque, they appear to be nearly inline as if the director is simply pulling the armature magnets around.
It seems to make some sense in that the same field force on a smaller diameter will take less torque to break free while the magnet tries to connect both poles by adjusting it's position moving the armature at it's larger diameter to do so.
I was thinking that once the director core was rotated that the field through the armature magnets would become weaker and break free from the stator with less force. But maybe not!


Watching the video carefully may reveal the effect causing the gain and how better results might be achieved.


There are also small laminated pole pieces on each end of the armature magnets that assure a strong field connection to both the director core and the stator core.

I'm doing a single test build to test the relationship of the director core and the stator index.
The build will allow me to vary the alignment of the armature and director core with the stator so the field connection to the stator can be weakened to allow proper indexing with the director core.


I had some .015 inch silicon steel laying around to make the director and stator. The stuff is hard on carbide tools.
Just waiting for the epoxy to set on the tiny armature arm.

The initial testing required the removal of half of the stator plates because they were overly attracted to the armature magnets.
On top of that, I had to shim the rotor up 1/8 inch to lower the field connection further to reach an acceptable attraction. Then I was disappointed that the director was just dragging the armature showing no useful gain.


Then!
I made a new director with the laminations vertical or opposite the stator laminations. When the director is rotated to the 90 degree point there is a very noticeable drop in the armature to stator field connection. I feel now that this device may in fact operate with some level of gain.
The new director works more like a shield or disconnect with the armature magnets reducing their fields as it now switches poles much easier and then aligns again with the director to apply full force at the next pole.


More testing required.

I went back to the old director (laminations same direction as stator) because even though the vertical laminations reduce the armature field strength, it doesn't provide enough pull to move the armature.
That sorta tells me that the director only pulls the armature to another detent and the only gain in torque is from the attraction to the next stator detent.


That means the attraction from the stator to the armature magnet must be less than the director to the armature.
This seems a bit like it could not provide any gain if that's the case but then even a smaller attraction at a point further out with greater leverage may be what's providing the increase in torque.


So where it's at now with a larger gap from the armature to the stator, it switches well when rotating the director. I have added some slots around the stator and plan to wrap these areas with coils to draw off power and create drag. The director rotation now is causing the armature to jump several detents now and by adding the coils I am trying to force a load that will help it jump a single detent drawing energy off each index.


Seems like a logical next step.