When I thought about making a nice cutaway, I came across an EVVA MCS from my collection. However the 'cutting away' task seems to be pretty difficult, probably involving making new parts from transparent palstic and so on, I still didn't figure that part out yet.
But: This lock is such a very nice piece of engineering, that I wanted to share some pictures with you
Remember: MCS is the 'Magnetic Code System' by EVVA (a similar technology was previously also used by Zeiss Ikon), as shown (in less detail...) on http://www.evva.com/McsFrameE.htm
Here is my lock:
The key has 4 magnets (or maybe 8, 4 on each side, I'm not sure about that) and some notches.
The housing (1) of course has the hole for the plug, and the wall around this hole has lots of grooves milled into it, which interact with the sidebars (see below). And it has 4 holes for pins and springs:
The 1.1.x combination of ball, pin & spring is used to retain the key while it's not in the 0 degree position (notch 3.1, see below). The other pins & springs (1.2 - 1.4) interact with the control balls 2.1.1 - 2.1.12 (see below). They would basically catch and lock the key in a 30 degree position, if too many notches were present on the key.
But now for the real beauty, the plug! It's made of several pieces & materials, e.g. brass, plastic, and of course samarium cobalt magnets
The 12 control balls 2.1.x come in 2 sizes: large when there should be a notch on the key, and small when there shouldn't be one. They are inserted into the plug from the outside and then fixed by deforming the plug a little bit. As said, the large ones will drop into the notches of the key (or block the plug in the housing if the notch is missing), the small ones will keep the pins 1.2 - 1.4 from catching the plug at +/- 30 degrees if there is no notch - or they will fall into wrong notches of a wrong key. This catching would be permanent, so these notches are not too useful for masterkeying...
On a side note, there is one more unused notch on my key, and the German version of the EVVA page http://www.evva.com/McsFrameD.htm shows even more difficult looking cuts, apparently to obscure the system a little bit.
But the main feature of this high-tech plug is the magnetic rotor / sidebar assembly:
The outer sidebars (2.2.1 & 2.2.2) are made from metal and block the plug from turning if not both sidebars are moved to the front of the cylinder. Each of them contains a small spring assembly, so that they can compress a little bit. The back ring (2.4.x) and the front ring (2.3) (both made from plastic) on the other hand move the sidebar to the back both at 0 and 180 degrees, and try to move it to the front at all other positions (which is required, so that the plug can turn more than a few degrees). Try, because they can only do that when the magnetic rotors are in the right positions. If they can't, the sidebars will compress a little bit (remember, they have the small spring assembly), but not move to the front, and not unblock the plug.
And below the plastic covers (2.5), there are the inner sidebars (2.6), another cover (2.7) which serves as a bearing for the rotors and finally the heart of the system, the rotors (2.8.x), 4 on each side of the plug.
The rotors have a magnet on one side, and a plastic disc with a notch in the correct position on the other. That means, the coding of the key is achieved by turning the magnets in the key appropriately. I guess that for masterkeying purposes, there could be more than one notch in the rotor disc, or there could be a rotor left out, etc.
There seem to be some inserts between the 1st and 2nd rotor, probably steel, to make drilling more difficult.
BTW, the whole system is *heavily* lubricated; I guess, if that's not done properly, the sidebar system would block after some time.
And now on the topic of 'picking' this lock: The rotors cannot be touched from the keyway, as there is a thin brass wall between the key and the rotor. That means, they can only turned by magnets (be that a permanent magnet or something else, but I guess that doesn't belong here).
So with mechanical tools, it will apparently be *very* difficult to pick this lock open. And if you tried to 'pick' each magnetic rotor separately, you would see that they interact with each other while no key is present, and tend to re-set / scramble themselves. And the sidebar releases them every 180 degrees...
In normal operation, the removal of the key will of course also scramble the rotors.
Well, that's all for now,
maybe you can give some suggestions on the cutaway task
Cheers,
mh
- part of one of my former jobs