Mortice lock, no keys, best way to make replacement keys?

[coffin_dodger]

Hi I had a customer bring in a mortice lock he had lost the keys to. He asked if I could make some replacement keys...(I'm a key cutter btw).



I have managed to Id the lock this morning as a Chubb (Union) 3G114 and have managed to make some replacement keys, but would be interested to know what is the best way to do this.

Here's the method I used.

I took the hard plate off the lock and removed the levers noting down the order of the 5 levers.



Luckily I had a few old chubb keys one from a 3G114 and one from a 7 lever chubb lock.



I placed one lever at a time in the lock ( on the lever pivot) and using the 2 old keys found the right cutting depth of each lever.

I then referenced each lever with the cutting depth I'd found above, to create a visual of how the key should look.



Next I used my mortice key cutting machine to cut the key out using a new blank and the 2 old keys as a template.

My 1st attempt was a disaster, as I mistook where the 5 levers fall on the 7 cuts. but realising my mistake I worked it out again and ended up with key that worked one way but not the other, I then filed the non working side down by eye using the working side as reference.

This worked perfectly and I was able to cut a 2nd key using the 1st key as template.



So although I'm delighted and have learnt a fair bit about locks today, it was fiddly, time consuming and possibly more luck than judgement that I got it to work.

How could I have done this better?

Thanks

Matt

[GWiens2001]

Think you figured out what is likely the best/easiest way. Also, you learned a lot. In some ways, it is good you did not succeed the first time, because you then had to troubleshoot the problem.

When you say it worked one way, but not the other, did you mean the key would lock but not unlock (vice versa) or that the key worked from one side but not the other?

Gordon

[coffin_dodger]

Hi Gordon

It worked from the side you can see both locking and unlocking, but from the other side it wouldn't open at all and closed with difficulty.

Regards

Matt

[GWiens2001]

Think the spacing of the cuts may have been too far to one side, or possibly not quite wide enough. Obviously, you worked it out. (Great job on that!).

One other way I have used aside from impressioning is to leave the cover off, insert a key blank, and turn it, lifting the levers. You can see which cuts need to be deeper for the post to fit through the lever gates.

Gordon