@ gwhy
You MIGHT be able to fudge on the horseshoe mags with hard drive mags.
I've had this idea for a while (and it seems Rusty has too, 'cept he's using HS mags
) as it's harder to come by horseshoe mags these days.
(I _think_ I've seen _1_ vendor offering horseshoe neos [supermagnetman.net who gives better volume discounts than magnets4less, but I haven't researched the shipping differences].)
From the ones I have here it seems the polarity has a unique arrangement as the sides of the mag are the opposite polarity of that on the face e.g.:
TOP (FLAT) SIDE (EDGE)
XXXX N X S
XXXX N X S
XXXX N X S
XXXX - X -
XXXX - X -
XXXX S X N
XXXX S X N
XXXX S X N
....although, I have found a few that seem to be.......
TOP (FLAT) SIDE (EDGE)
XXXX N X S
XXXX n X S
XXXX s X S
XXXX S X -
XXXX S X -
XXXX s X N
XXXX n X N
XXXX N X N
Which is really confusing as I'm used to mags having diametrically opposed polarities.
So maybe stacked HD mags to get a greater area edge effect ?
This is not something that'll be that easy as the epoxy used to hold the HD mags to the metal backing for mounting in the HD is not that easy to break.
I've found (this has worked for me with 80/20% success rate) that you can use a guitar string (G (unwound), B, or high E) as a rope saw if you can get it between the metal mount and the mag to defeat the epoxy.
A question I have about your trigate/MkE-oneway marriage is, does the MkE have to have such sharp right angles?
Could a slope (before the crucial 2/3's point of the MkE) marry the MkE field to the trigate field and allow each (MkE slope) start to have the acceleration effect restart at each MkE beginning to negate the "wall"?
Have you set up multiple arrangements of these end to end to see if that is possible and you can create a loop without turning the arrays into a large multi-piece ring mag?
Like this:
T = trigate
M = MkE
<-------------<------------<----------<----------
T T T T MMMMM T T T T MMMMM T T T T MMMMM T T T T MMMM
M M M M
M M M M M M M M
........so instead of the MkE array being formed thus:
__________
-
-
-
__________
.......it is formed like this?
___________
-
-
-
________
That way it is covering the same area, but the 1/2 way point is still (marginally) allowing the roller into the trigate with its accumulated acceleration?
Just questions and wool-gathering dude.
I do have to give you major kudos, as in another thread we've both participated in, array use seems chained to 2D thinking, whereas you've broken out of that mold and started thinking 3D which seems to be (the more I play with this stuff) the best way to think about array usage.
I'll be posting more of my recent failures over there shortly, and invite you to take a look as my failure MIGHT show you something it didn't show me and lead to your success.
P.S. I just (finally) watched the vid you posted and I was wondering had you tried the roller without the BBs on the end yet?
Was the behavior any different?
Have you considered slotting a piece of plexi or other plastic to allow it to be sloped or form the MkE more uniformly?
What happens when you have the MkE formed as you do, but there is no receiving trigate on the end?