sfic a2 math question

[bthom73]

I'm in the process of learning the algorithms behind the SFIC A2 system, and I'm hoping someone here might be able to let me know if I'm on the right track.

Assuming a total position progression system where there's one top master key, one control key, and several change keys, according to the math I've done so far, the top pin is always in the size range 4-13, control pin 2-17, master pin 2-9, and bottom pin 2-7. That would mean that standard (top/control/master) pin sizes 18 and 19 and bottom pin sizes 8 and 9 are never used due to the master pin consuming a minimum of 2 increments.

If anyone can let me know if that makes sense or if my math is flawed, either way I'd greatly appreciate it. Thanks.

[straightpick]

Assuming a total position progression system where there's one top master key, one control key, and several change keys, according to the math I've done so far, the top pin is always in the size range 4-13, control pin 2-17, master pin 2-9, and bottom pin 2-7. That would mean that standard (top/control/master) pin sizes 18 and 19 and bottom pin sizes 8 and 9 are never used due to the master pin consuming a minimum of 2 increments.

What, you got something against 0 and 1 bottom pins? If you had a 0 cut on a change key and a 8 cut on the master, what's your bottom pin? If you had to pin a core direct to the master, which is no other key except that one and the master key operates it, and the master key had an 8 or 9 cut in it, you need the 8 or 9 bottom pins, as that key has to have some of the master key cuts on it. Also if you need a core pinned direct to the control key, which means that only that key and the control key will work it, (the control key serves only to remove it), and that key had a 0 cut in the first position and the control key had a 9 cut in the first position, that's where that 19 pin comes in handy!

[Raymond]

Ditto, I agree with the previous.

I just wanted to add that original Best pin kits come with #1 master wafers and they use them in their systems. Seems way too thin for me though.

The control key can use the 0, 1, 8, or 9 depth as its combination of pins can be outside of the normal progression due to the separate shear line. Also, many of the control cuts can be the same as the grand master's to prevent interferrence with the bitting progression without compromising the security.

[WOT]

Ditto, I agree with the previous.

I just wanted to add that original Best pin kits come with #1 master wafers and they use them in their systems. Seems way too thin for me though.

I wasn't aware the #1 master pin existed for A2. It does for A3 and A4. The thinnest best pin is the #1 for A3, which is 18 mils. A2's #2 is 25 mils. I don't think the 12.5 mil #1 ever existed for A2.

[Raymond]

Hello!
A year ago I would have agreed with you just on principle. However, I recently asked an aquaintance if he could pin up a lock (A2) with a bottom pin of 9, and a control cut of 0. This would require pins: 9, 1, and 13. I thought it was a trick question for which there would be no correct answer. He opened his Best pin kit to show me the 12.5 thousandths #1 wafer.
I didn 't believe it until I saw it. I still would not feel safe using so thin a wafer.

[straightpick]

A year ago I would have agreed with you just on principle. However, I recently asked an aquaintance if he could pin up a lock (A2) with a bottom pin of 9, and a control cut of 0. This would require pins: 9, 1, and 13. I thought it was a trick question for which there would be no correct answer. He opened his Best pin kit to show me the 12.5 thousandths #1 wafer.
I didn 't believe it until I saw it. I still would not feel safe using so thin a wafer.

Yes, the older Best pinning kits DID have #1 master wafers, I recently found a pack of #1 wafers in some old supplies that I had purchased. But they are not available now (for the A-2 system) as they are only .125" thick and caused many problems with jamming, not to mention that they take the system out of parity (even-odd). They are NOT recommended for use if you have them.

[yoyoboy]

best used to use one step progression master key systems, but has since stopped due to interchange problems between sysyems.
The problem with one step systems is that there is no parity of the bitting, so every system has exactly the same cuts in it.