Want to learn how master keyed systems work? not sure what a Grand Master or a change key are? Want to share a new MK system you came up with? How do different manufacturers pin up their locks? It's 10pm, do you know where your wafers are?
Hi All, can some one please shed some light on this as it does not make sense to me, I figure that chamber position 3 should not have a master pin, please help as I am trying to learn locksmithing and this is confusing me. The below info is what I have read in a book.
Using the known master key depth, subtract the depth of the change key from it. The difference is the length of the master key pin. If the change key is 46794 and the master key is 68495, the master pin combination will be as follows:
Chamber position, Bottom, Master 1 4 2 2 6 2 3 7 3 <<---- This is confusing me 4 9 0 5 4 1
I would like to know if this is a typo or some sort of weird mathematics, because when I went to school 4 minus 7 did not equal 3 ( more like minus 3 )
I am still learning as well but ill give a stab at trying to help....I see a couple things wrong here.
First no cut in your change key should be identical to the corresponding cut in the master key. The cuts should be either higher or lower (but not the same) in order to eliminate cross keying (change keys opening locks unintentionally). Your example with change key 46794 and master key 68495 both use 9 in the fifth position.
Second, your not always subtracting the change key from the master. What you want to do is pick out the lowest cut for each position between the master key and change key. So using your example (I changed the master's fifth position from a 9 to a 7 so 9 is not used twice).
Change key - 46794 Master - 68475 ------------------------ Lowest cuts - 46474 This will be the bottom pins you will use.
Now you want to find the difference between the highest number and the lowest number for each cut. These numbers will be your top master wafers. 6 - 4 = 2 8 - 4 = 2 7 - 4 = 3 9 - 7 = 2 5 - 4 = 1
So we now have.... Bottom pins: 46474 Top wafers: 22321 ------------------------ So now the lock will work with change key 46794 and master key 68475.
Also another note, depending on the lock some master key systems require more then 1 numerical difference between cuts. A difference 1 between cuts requires using a #1 wafer which is very very thin and can cause problems in the lock. Stick with a difference of at least 2 between cuts so avoid this problem.
Hi guys, thanks for the help, cheerIO did you use Divinorum's idea of changing the master's fifth position from a 9 to a 7 to get your result, if not, then how did you come by that result ( sorry to be a pain in the side )
No. I just went by your proposed cuts. I do think that his idea is a good one though.
My solution: 4 6 7 9 4 : change key 6 8 4 9 5 : master key ----------- 4 6 4 9 4 : lowest cut of either key, this is the bottom pin value 2 2 3 x 1 : the difference between the low number and the high number, this is the master pin value
Here is a really good video by kokomolock which goes step by step:
No problem. I got a bunch of cheap Kwiksets from my local building salvage place for 10cents each. I also bought a goldfish bowl of old keys at the flea market for a couple bucks.
I picked all the locks, pinned them up to work with the old keys, and masterkeyed a lot of them just to try it. It really was a great learning experience and the whole process is much clearer when you are actually doing it. Grab a cheap pinning kit and give it a try. It's not as hard as it initially seems.
You are mistaken if you believe no cut in the master key should be the same as a change key. It depends on what level you are keying to. My rule of thumb is to use the least number of master pins to get the job done. I did a very small system for a restaurant today and there were 3 constants in the locks.
The more master pins the more keys will work, both intentional and unintentional (ghost keys). With constants you eliminate quite a few ghost keys.
In most (but not all locks) a 1 step isn't used and in those systems parity must be maintained between all keys in the system.
Hi cledry, I am new at this and trying to learn, so please excuse me if this is a silly question.
When you are stating that In most (but not all locks) a 1 step isn't used, does that mean the masterkey should have the cut adjusted lower to be able to rotate the plug.
Going by the example above of 223x1 with a masterkey bitting of 6 8 4 9 5 , would the cut have to be adjusted to 6 8 4 9 4 if I do not use the 1 from the example or am I way off track here.
In theory I would only use 223xx. Is this correct
Thanks cledry, Bazza
Last edited by AusBazza on 15 Jul 2014 20:26, edited 1 time in total.
cledry wrote:You are mistaken if you believe no cut in the master key should be the same as a change key. It depends on what level you are keying to. My rule of thumb is to use the least number of master pins to get the job done. I did a very small system for a restaurant today and there were 3 constants in the locks.
The more master pins the more keys will work, both intentional and unintentional (ghost keys). With constants you eliminate quite a few ghost keys.
In most (but not all locks) a 1 step isn't used and in those systems parity must be maintained between all keys in the system.
From what I learned in a course it was recommended to never have constants. Though I can now see how this rule really only needs to be applied in larger systems. If it's a large master key system with higher levels the rule should be followed, however if its a much smaller system with say only 1 level then it can be placed aside as long as you pay really close attention to your pinning combinations. Saving master pins sounds good to me!
cledry wrote:You are mistaken if you believe no cut in the master key should be the same as a change key. It depends on what level you are keying to. My rule of thumb is to use the least number of master pins to get the job done. I did a very small system for a restaurant today and there were 3 constants in the locks.
The more master pins the more keys will work, both intentional and unintentional (ghost keys). With constants you eliminate quite a few ghost keys.
In most (but not all locks) a 1 step isn't used and in those systems parity must be maintained between all keys in the system.
From what I learned in a course it was recommended to never have constants. Though I can now see how this rule really only needs to be applied in larger systems. If it's a large master key system with higher levels the rule should be followed, however if its a much smaller system with say only 1 level then it can be placed aside as long as you pay really close attention to your pinning combinations. Saving master pins sounds good to me!
Don't believe all you are taught in courses.
Did they say why you mustn't use constants in a MK system?
In a larger system you cannot really have a constant, simply because you need many levels and or change keys. For example in the small system I did today I could only add a few more change keys before the second level MK wouldn't work. Basically though this restaurant chain always has a MK that works all the locks, a second level that works all but 3 locks and finally a change key that works just a few doors.
If you have a 6 pin lock and use a master pin in each chamber I guess you would have 34 ghost keys in addition to your change key and MK that would work that one lock. So it is much better to use constant cuts in as many chambers as you can.
Not sure if they still do but Schlage doesn't use the cuts 0, 1, or 2 unless part of a system. So if you make your Schlage keys with constants using those depths you should never have a random Schlage key operate any of the locks you have masterkeyed. Other manufacturers have similar rules and after many years you tend to use these things to your advantage.
Divinorum wrote: From what I learned in a course it was recommended to never have constants. Though I can now see how this rule really only needs to be applied in larger systems. If it's a large master key system with higher levels the rule should be followed, however if its a much smaller system with say only 1 level then it can be placed aside as long as you pay really close attention to your pinning combinations. Saving master pins sounds good to me!
It sounds as if you were only taught one method of creating master keying systems, the Total Position Progression (a.k.a. "odometer method") by someone who doesn't possess enough knowledge on the subject matter to be in a position to be teaching other people about it...
This "rule" you state is the descriptive feature which allows you to determine what type of master keying system you are working with, in a Total Position Progression method system the top master key and change keys will never share any of the same cuts...
There is however another method used by experienced locksmiths to create master keying systems called Rotating Constant (a.k.a. "Hold and Vary") where every key in the system will share one or more of the top master key bittings (a specific number is chosen when the system is designed, for instance 3-in-6 would mean 3 cuts of the TMK will appear on every change key in a six pin lock) where the positions of those shared cuts is progressed using a pattern chart... You can create fairly large keying systems this way...
Rotating Constant works well because you can reduce the number of master pins you are using in the system and key interchange is prevented because the constant cuts of the master key allow you to only pin ONE cut into those positions as you progress through the patterns, so other change keys from the other patterns in that system cut to a different bitting in those positions will not operate...
AusBazza wrote:When you are stating that In most (but not all locks) a 1 step isn't used, does that mean the masterkey should have the cut adjusted lower to be able to rotate the plug.
There are different "rules" regarding selection of top master key bittings and progressing change keys beneath them...
Some locks require 1-step progression and others require 2-step progression... The "steps" mean that valid keys in the same keying system will always be one or two apart from each other... With 2-step this means Odds/Evens: 0, 2, 4, 6, 8 OR 1, 3, 5, 7, 9 in a given pinning chamber and using bitting parity in designing the system... With 1-step progression you can use all depths in a pinning chamber: 1, 2, 3, 4, 5, (etc)...
The most common examples of this concept are Kwikset which uses 1-step progression as it uses increments of .023"... Schlage uses 2-step progression as it uses increments of .015" which are too small to properly prevent key interchange...
This can get confusing when you consider that some lock manufacturers can have cylinders which can use 1-step progression or 2-step progression like Corbin-Russwin where 1-step is called "System 70" and 2-step is called "Pre-System 70"...
