Builders locks and self-repinning locks

[heydonms]

Hi,

I've just recently started messing around with lock picking, while reading up on the various types of locks I came across two in particular that I couldn't visualise the inner workings of.

The first was referred to as a construction lock and was intended for use in new houses. It had multiple keys, the first key was used by the builder, after the house was built, the sales team came along and used their key at which point the builders key would no longer work. Same thing when it was sold, the owner uses a different key which locks out the sales key. (Sorry I can't find the URL where I first saw this which had a better description)

The second lock would match itself to your existing keys, you used the key that came with it to turn it to a "reset position" or something, put in your house key and the lock was repinned to to match your house.

I've searched the forums without success (That may be more because I don't know the correct terms than anything else :/ )

If anyone could point me to a simple demo of how these work or explain how they differ from a normal pin tumbler lock it would be much appreciated.

-- Michael

[nekret]

construction keying is pretty simple, there's a series of ball bearings in the pin stacks that are normally kept in the plug while turning but when the customer key is used there are divots in the outside of the plug that trap the ball bearings thereby locking out the construction/sales keys.

As for the smartkey/uchange type stuff take a look at zeke's pictures in this thread: viewtopic.php?t=19435

[Eyes_Only]

I know the construction master keying has ball bearing or something in the pin stacks that allows that key to open the lock but when you work the homeowners key in it the ball bearings are pushed up past the shearline and as you rotate the lock they fall into small holes next to the holes for the pin chambers in the plug effectively stashing them away for good never to be used again. I think thats how it works.

[heydonms]

Ok, so in the case of the construction lock, once the ball bearings are out of the way it is pretty much the same as any other pin tumbler.

The smartkey thing is way over my head, I'll have another look at it in a month or three and see if I can make sense of it then.

Thanks

[Eyes_Only]

I don't get it either. I'm gonna wait till they sell the locks at Home Depot and take it apart to figure it out.

[globallockytoo]

the ball bearing construction keying system is found commonly in many Kwikset and Dexter locks.

Other systems use a part of the customers key (the end or last two cuts) with a hook built in.

The builders key will usually be a 3 pin key (shorter). When it comes time for the customer to block out the builders key, they insert another 3 cut key with the opposing hook, which pulls out the end stuck in the lock. The only key that will work now is the correct 5 pin(cut) key.

The way the ball bearing system works is, the customer has a key cut slightly higher in the positions where the ball bearings are. Inserting this key and turning once will drop the ball bearings into small holes in the plug that correspond. Now the only key that will work is the correct key for the lock...all others will be locked out.

[nekret]

The smart key system is pretty ingenious in how it works. the pins have small ridges on one side of them as seen here ->
http://img.photobucket.com/albums/v375/ ... sk6smt.jpg

Those ridges then fit into one of the serrations in the wafers as seen here->
http://img.photobucket.com/albums/v375/ ... sk7smt.jpg

Only when that deep groove is lined up will the lock turn. I believe the rekeying tool forces the wafers to remain in the open position however the sidebar gets retracted allowing the main pins to move freely. Then a new key is inserted and the rekey tool is removed causing the sidebar to be released and letting the wafers contact the pins again effectively setting the new code for the lock.

Again, thanks to zeke for the pictures and this is only my guess of the rekeying procedure (zeke please correct if I'm wrong).

[heydonms]

aaaah... ok I think I get it, I don't quite see what all the holes in the shell are for, but I can see how the sidebar assembly slides back so the pins can move and then forward again catching the pin in the new slot.

If I am looking at it right then there are 6 possible cuts for each pin. (is cuts the proper word or should I say bittings? or are the two terms interchangable?)

-- Michael

[nekret]

aaaah... ok I think I get it, I don't quite see what all the holes in the shell are for, but I can see how the sidebar assembly slides back so the pins can move and then forward again catching the pin in the new slot.

If I am looking at it right then there are 6 possible cuts for each pin. (is cuts the proper word or should I say bittings? or are the two terms interchangable?)

-- Michael

The holes in the shell are to allow room for the wafers to move up and down (I'm guessing). As for having 6 possible depths this seems a bit odd to me as kwikset specifies 7 possible depths and weiser specifies either 9 or 10 if I remember correctly. so even though it still uses the KW1 it might have different depth and spacing specifications.

[greyman]

That Weiser smartkey looks a fair bit like the Rielda (Lynx) mechanism, which is key changeable. But let's not be confusing this with the idea of construction keying. The latter is much simpler - as previous posters said, the owner's key pushes one or more stacks up just a bit higher than the construction key. This allows a ball bearing (that was previously below the shearline) to now be positioned above the shear line. When the plug turns, the ball(s) get trapped in holes in the plug that have a depth equal to the diameter of the ball. The ball(s) are therefore eliminated from the stacks and the construction key no longer works.

[heydonms]

This image http://img.photobucket.com/albums/v375/ ... sk7smt.jpg looks like it has 6 positions for the pin to latch onto which is where I got the 6 cuts idea from, maybe it doesn't work quite like I thought

I realise the smart key stuff isn't related to construction keying, I just happened to ask about them both in the same post. The smart key stuff looks like the more interesting of the two.

[zeke79]

For a reference here is a lynx/reialda lock broke down. You can see how the lynx and weiser differ.

http://img.photobucket.com/albums/v375/ ... email1.jpg