Tips on pinning systems.

[Raccoon]

I'm writing a script to generate pinning sequences based on a number of user-selectable criteria. I would like some input from people familiar with pinning as to what makes a type of sequence secure or insecure.

I'm going to start with simple non-mastered 5 pin kwiksets, then expand the script to include any number of pin and hopefully design a complete mastering system.

For now, I'm interested in what makes pinning more secure than not. Obviously a sequence of 3-3-4-3-3 can be easily picked with a paperclip, while a sequence of 6-2-6-1-3 could be rather difficult to pick with anything but a set of Falle hooks.

Besides the fact that 1 or 2 really low pins acts as a good shield against picking, what are some other considerations to make? Should each pin be no less than 2 depths apart? Ie, never put a 2 next to a 3, or a 4 next to a 5? Or should one strive for even greater staggering of pins? Are there any drawbacks to this, besides limiting the total number of pin combinations possible?

Any input would be welcome so I can test a number of algorithms and compare them.

[Lock Jockey]

Sounds like a good idea. A system ot create grandmaster/master key systems would be awesome. I also suggest that in addition to not making pins too close together that you don't make them too far apart. I believe that most brands have a set amount of distance that is the max between neighboring pins to allow the key to go in and out smoothly.

[Raccoon]

Any written schematics on this, or experience from practice would be welcomed. I'm going to need as much info as I can get for each brand of cylinder. I can see how jumping from 9-1-9-1-9 would be pretty excessive and will have to figure a way to limit this.

I will need a good idea of what the maximum threshhold is, as being TOO modest will limit the number of combinations possible and potentially create keys that inadvertantly open other doors (especially in a master system).

I'm also going to take into consideration the angle of cuts for these brands, and try to avoid keys that open doors when pulled out half-a-notch, or pulled out a full notch with the furthest pin resting on the head slope of the key. If for instance, the slope causes the furthest pin to rest at the 4 position, then I should avoid using 4 as the last pin for any and all locks of that brand.

[Chrispy]

I can see how jumping from 9-1-9-1-9 would be pretty excessive and will have to figure a way to limit this.

Not only would it be excessive, it wouldn't work. I can't imagine a single MACS that would be 8.

[Chucklz]

Get the min and max cuts (0-9, or 0-7, or 1-8 or whatever). Generate 5 or 6 random numbers limited to the available cuts. Check for MACS violations. Done.

[Raccoon]

Where can I find these MACS specs?

I'm sure I could figure out a physical maximum threshold based on the pin-center spacings, the width of the bite, and the angle of the slope. For instance, a 0.125 bite spacing with 0.051 spacing between pin center (on both sides) followed by a 90 degree slope to the next biting should reveal how tall the slope can get before it must end (and become verticle). But getting true specs would be more favorable.

[n2oah]

Where can I find these MACS specs?

http://www.dlaco.com/spacing/spacing.htm

[Varjeal]

If I recall Kwikset has a MACS of 4. If you limit the combinations as you mentioned previously with a minimum diff of 2, (which is a good idea) you are definitely going to cut down on the # of changes you can possibly have.

What you may want to do, and I don't know how you'd program it, is to allow only ONE instance in a particular bitting of two positions being within 0 or 1.

[Raccoon]

Thanks for all the replies. It appears many of my posts are leaving the General Chatter forum and finding their way here. I'm only now discovering this, and finding all these posts that mysteriously vanished and I forgot about.

Yes Varjeal, that should be very possible. I'm going to design bitings based on relative positions instead of absolute values. Eg, the first biting will always be 0, and then move up or down. 0,-1,2,2,-3. Which could equate to a key like 3-2-4-6-3. This can be useful for increased security if such a combination is only allowed to be used once. In that way, the key 2-1-3-5-2 could not exist, because the first key could potentially open it if pulled out 1/4 of a notch.

I'm experimenting with how many combinations are possible with this method in mind, and in combination with a master system. One should at the very least make sure two matching keys of this kind are not used in the same hallway or building. A good example of this is my and my neighbor's key. My neighbor's key is relatively the same but +1 on all bitings. Her key opens our door when pulled out 1/4 of a notch.

[maxxed]

The macs on a system will be determined by the width of the cut ( that in turn is determined by the type of pin typically used ) , the angle of the cutter used on the code machine. If you are using factory type kwickset pins then the keys need to be cut with a wider flat, if you use universal lab pins then you can cut a narrower flat on the key and increase the macs. This will give a greater number of keys available on a master key system.

I wrote a program many years ago that simply added 2 to the final cut until that chamber reached 9, or 7 in kwickset and then advanced the count on the 4th cut

1 2 3 4 5
1 2 3 4 7
1 2 3 6 1
1 2 3 6 3
ect
kinda like watching a cars odometer

I did exclude the cuts of the master key from the change keys, hope this helps you with the consept.

Another tip

All keys in a master system should have the last cut run out to the end of the blank, that is cut at the depth of the final cut to the end of the blank. This would prevent a key from opperating another lock by pulling back on the key.