Cutaway Lever lock - homemade

[fgarci03]

Today, I made a cutaway of a CISA Lever lock I have around here. Actually I have two (one is for sale), and I have made a breakdown of this lock before here: viewtopic.php?f=9&t=56517

So here's a couple of pics:

Cutted pieces:



The lock after cleaning (disassembled):


Front and back (already assembled):


(The lock has 6 levers, with the bolt in the middle. So it needs to be cut in front and back so we can view all the levers)

Key operating the lock:



As you can see, this is not a work of art. The cuts aren't perfectly aligned and in the front I cutted a little more in the corners than I should. But it's my first time using a dremel (just bought a cheap one ), and what better to cut than a lock full of strange angles with double hardened plates?

I weared out 4 discs to cut all of these (they were also cheap). I mean, I had to replace them before they reach their limit, so I could cut the deep double plates. But it was cool!
After cutting, I smoothed the cuts with a file (not to make it prety, but to be able to NOT cut myself with them ) and cleaned the whole thing with wd40.

This was my first attempt at either a cutaway or using a dremel, so I think it came out a pretty positive experience (the lock still works, and I still have all my fingers!)

[youngpicker99]

It looks very good for you first time making a cutaway. The first time I used a dremel I made a hook pick out of a butter knife it looked horrible and would not fit into any locks. I wish I still had it so I could post pictures of the first pick I ever made.

[GWiens2001]

Not being familiar with many lever locks, please correct me if I am wrong. The reason for all those teeth in the levers as seen in the window you cut is that the key turns multiple turns in the lock, each time moving the bolt further in/out, right?

Gordon

[ARF-GEF]

Gordon: Yes. The little stub moves through one "gate" each time you turn the key. If the key has to be turned 4 times the will be 4 gates. Normally every second gate is in the same position, since one side of the key daises the sheets to the same defined level. If the key has different biting on the 2 the 2 gates can be at completely unrelated positions.

[fgarci03]

Absolutely right.

I'll be making a video tonight to show the key operating the lock. It also features a system where there are two different keys to the same lock. I'll be calling them Master and Slave key (don't know the actual names of them).

What it does is this:
- Master key can operate the lock to it's full extent. It can turn all the way through all the gates
- Slave key can only lock/unlock the first two gates. That's the key I have for this lock.

On the video I'll be showing that specific gate.
It's used to, for example, give one key to your maid so she can enter and exit the house. When you go on vacations, you lock with 4 turns. That way she cannot get in. When you come back, only lock with 2 turns again so she can get in.

Or you could use it to control your kids time of getting home at night xD
If it's locked with 4 turns they will have to wake you up to get in, so you know what time they got home.

Lucky my mom didn't know this feature on my 16's! She used to just let the key in the inside, and most of the times I managed to remove it without waking up anyone. And then I told her I was already sleeping when she locked up

[GWiens2001]

Seeing that you have a cutaway to see what is happening with the levers and gates, couldn't you make a 'master' key? It seems that the 'slave' key would simply not move one or more of the levers, preventing the bolt from moving past a certain point. It should be fairly easy (in theory, remember that you probably know more about lever locks than I do) to see which lever(s), and therefore key bits, need to be modified to make your 'master' key.

Gordon

[ARF-GEF]

You could make a slave key which can only turn once (has only one side correctly cut/cut at all). You could use it to restrict access ( 2x locked with the "master" key and the slave key won't open it, only locked ones the slave key can open it.) I think this would be some sort of shop-keying (?)
You can also masterkey the locks with having gates made wider (so that there is more than one biting which lifts the lever and thus the gate into an open position).

[ARF-GEF]

I think you could also have wider gates on some levers at the first two "turns" but by the 3rd turn you could have the gate tighter again. This way both keys could turn it twice but only the master key could turn it the 3rd time. But again I can barely see any practical use for it especially in the age of cheap and readily available electronic locks which can have very elaborate restrictions and programming with audition and so on.
If you do I would be very interested to hear it.
In my eyes a good electronic lock is a lot more practical than those long and clumsy keys, but that's just a personal preference.

I think you could in theory build systems in which there are 2 slave locks only opening the exact lock but not the other and a master lock opening both. But in bigger systems it would greatly reduce security and it would be so complicated. I don't have an actual lever lock here so I'm not sure about it at all.

I've also seen some old and interesting French lever locks which need 2 keys (one can turn it the first time then the second can turn it the second time..) I think it was used for bank deposit boxes. Fascinating stuff.
But as I said before with more complicated usage requirements you can't beat the electronic locks. As said it makes me I think in the banking sector the time of the keyed safes locks is over.

[fgarci03]

Well, my phone makes video with crappy quality, so I'm going to stick with images
So, to start let me explain a few things:

Seeing that you have a cutaway to see what is happening with the levers and gates, couldn't you make a 'master' key? It seems that the 'slave' key would simply not move one or more of the levers, preventing the bolt from moving past a certain point. It should be fairly easy (in theory, remember that you probably know more about lever locks than I do) to see which lever(s), and therefore key bits, need to be modified to make your 'master' key.

You are right. You seem to have completely understand how these operate, and yes, It wouldn't be too hard (assuming I can impression... I've never done it yet and it will be a great project for me!)
In order to do that, I would need to cut the key exactly like the one I have, but the middle section (where it has a gap), in there I would have to see just how much to cut to make it lift the lever to the exact spot.
Here's an image of the first two levers, notice the lack of notches on the first two gates, wich allows a completely filled down key to operate those levers:


And here's the 3rd gate not allowing the bolt to go further (I'm trying to turn the key in this image):

You could make a slave key which can only turn once (has only one side correctly cut/cut at all).

In theory.. Yes. But it would bring problems. As you can see in the image, the key has a small notch on one of the sides. That is meant to make you insert the key on the correct position and not upside down (see the keyway image). So, you always have to make 2 turns in order to remove the key from the lock. If you lock with one turn, the key will not come out.
You could remove that notch but when someone turns only once and remove the key, original keys won't fit since you would have to insert a key upside down to operate the lock.
You could however use that key only to open the lock when unlocked, since it only retracts the bolt and then comes to the original position. But if the lock was locked, the key would unlock 1 turn, and if you don't turn again it would happen what I said before.

You can also masterkey the locks with having gates made wider (so that there is more than one biting which lifts the lever and thus the gate into an open position).

I'm not sure about this, but I think that is how masterkeying lever locks is done. It however brings up the same problem as pin tumblers, less security, as it gets easier to lift the levers to the right position since the smal channel where the bolt has to pass is wider.

In my eyes a good electronic lock is a lot more practical than those long and clumsy keys, but that's just a personal preference.

I think that way too. But here in Portugal it's very uncommon. The only electronic locks you usualy find is on buildings to open the front door (and it's not very common either).
The most common locks are regular pin tumblers for older houses, Dimple or Lever locks for everything else.

A friend got me an internal police document with a bunch of photos of people who are known for lockpicking to steal houses. They have homemade lever lockpicks. They are also able to open cross locks and cheap pin tumblers but they specialized on these.

But as I said before with more complicated usage requirements you can't beat the electronic locks. As said it makes me I think in the banking sector the time of the keyed safes locks is over.

In fact, most high security safe locks (at least arround here) use lever locks like this. Probably with anti-pick levers and so on. But mainly lever locks, combined with some sort of combination system (either the regular combination lock, or 3 or more wheels with 1 letter each to make a word). About he banking sector, I'm not sure...

Darn, you both have only seen this lock on these pictures and you already know as much (or even more) than me about it


NEXT PROJECTS:
- Make working "master" key
- After picking it easily, modify the gates in order to have anti-pick notches. If that's a viable project, I could turn the lever locks I use on other applications safer without spending a dimme

[GWiens2001]

You won't really need to be able to impression the key since you can see the levers in the window. Since you know which lever(s) need to be lifted, do as you suggested and make a duplicate if your current key with the cuts for the levers that need to be different left uncut. Then put your 'master' key into the lock and try to turn it. The lever(s) that new to be modified will certainly be over lifted at first. Just cut down the bitting at the required locations a little bit and try it again. Wash, rinse and repeat until the key is correct.

You might have to do the same thing on both sides of the key, but that should do it.

Gordon

[fgarci03]

My great doubt is, do I do that with just a simple file? Or are there better tools for that? I can't imagine a file so slim that could make a cut like that

[zeepia]

My smallest file´s flat edge is around 1mm. How wide are your key´s cuts?

[fgarci03]

I think 1mm too

Didn't know there were such files... aren't they too fragile?

[zeepia]

Actually I have given them quite an abuse and still haven´t broke any. Mine is a cheap set with 10 pieces and then a couple of Grobet needle files. Couldn´t believe my luck when I got them from flea market, three files and some other jewelry tools for 2€, retail price for those files is around 20€ per piece.

[fgarci03]

WOW.

I can't get anything for that price here. Could you post a photo of the kit?

Please, if you find something like that again tell me and I'll buy it from you