Rotating Constants

[chieflittlehorse]

I was reading THE MASTER PLAN by Billy B. Edwards, Jr. - An Explanation of the Principles of Master Keying... Whew... out of breath from reading that....

So my question is does anyone have more information concerning Rotating Constants when masterkeying.

The chapter in the book does nothing but confuse me.

So any expanation with be helpful.

Thanks...

CLH

[jharveee]

rotating constant
n. one or more cut(s) in a key of any level which remain constant throughout all levels and are
identical to the top master key cuts in their corresponding positions. The positions where the top
master key cuts are held constant may be moved, always in a logical sequence
rotating constant method
n. a method used to progress key bittings in a master key system, wherein at least one cut in each
key is identical to the corresponding cut in the top master key. The identical cut(s) is moved to
different locations in a logical sequence until each possible planned position has been used.

Credit given to Lock Industry and Training Council.

[dmasters]

My take on it: Any given change will always share a single cut with your TMK. Change AA1 may share the first cut, while change CE17 may share the 3rd cut. I can visualize it, and I started scribbling one out, but I don't know how else I can explain it short of pictures I'm thinking you would end with way fewer changes in your system with this method and it wouldn't be as secure.

Are you studying/learning or attempting to utilize the method? While not a fan of the man's personality or politics... Don O'Shall wrote THE book on masterkeying and is a true (living) icon of the industry. Actually, he wrote several books... pick your poison

http://www.locksmithingeducation.com/catalogue.htm

[chieflittlehorse]

The reason I'm trying to learn it is to make a program utilizing the rotating constants method. But the book I read did not explain it very well to me and had only a few examples.

I'm sure I will figure it out but I'll still stick to my method of masterkeying.

-CLH

[Farmerfreak]

Example
Note:X is any depth other than the master keys depth in that position.

Master key is 123456

Possible rotations.
1xxxxx
x2xxxx
xx3xxx
xxx4xx
xxxx5x
xxxxx6

or

12xxxx
1x3xxx
1xx4xx
1xxx5x
1xxxx6
x23xxx
x2x4xx
x2xx5x
x2xxx6
xx34xx
xx3x5x
xx3xx6
xxx45x
xxx4x6
xxxx56

or

123xxx
12x4xx
12xx5x
12xxx6
1x34xx
1x3x5x
1x3xx6
1xx45x
1xx4x6
1xxx56
x234xx
x23x5x
x23xx6
x2x45x
x2x4x6
x2xx56
xx345x
xx34x6
xx3x56
xxx456

or

1234xx
123x5x
123xx6
12x45x
12x4x6
12xx56
1x345x
1x34x6
1x3x56
1xx456
x2345x
x234x6
x23x56
x2x456
xx3456

or

12345x
1234x6
123x56
12x456
1x3456
x23456

Let me know if I missed any

[chieflittlehorse]

Thank you! That's one of the best examples I have ever seen.

Now I have to read that book again with more understanding.

I'll probably have more questions for you later though.

Thanks a bunch!

-CLH

[GringoLocksmith]

What's the virtue of maintaining these rotating constants? Is it just a systematic way of minimizing the number of stacks with master pins in them?

[Farmerfreak]

What's the virtue of maintaining these rotating constants? Is it just a systematic way of minimizing the number of stacks with master pins in them?

Depends, if all you need is a master key and a TON of change keys. Rotating may be the way to go.

For example, a typical Schlage master key system can get you four change keys per space. If master depth was say 4, then all the change keys in that space would be 0,2,6, and 8. Then multiply 4 to the 6th power and that's how many individual changes you'd get in a typical 6 pin master key system. (4x4x4x4x4x4=4,096 minus the keys exceeding the MACs)

Taking my first rotating constants example. 1xxxxx,x2xxxx,xx3xxx..etc. You'd get 4 to the 5th power multiplied by 6. {(4x4x4x4x4)x6=6,144 minus the keys exceeding the MACs)

So, in short 4,096 individual change keys, or 6,144 individual change keys when rotating constants.