I've got an interesting project in mind. I have a 1979 Porsche 928 whose
ignition keys are on their last legs. I have one (relatively) unworn key
kept in reserve with the idea that it could be used as a master for making
duplicates. The locks all seem to be in good condition, as the one good key
operates all of them easily. But I don't want to start using this last key,
as once it is worn out, that'll be the end of making a duplicate with a
pattern copyer. However, due to the 'strange' design of old Porsche keys,
no local locksmiths can duplicate these on standard equipment. The cost of
having a new key made from the VIN number, or by a specialty locksmith is
on the order of $150 to $200.
Although the keys are of an unusual configuration, they don't appear to be
that difficult to make on a mini-mill. I can measure the one good key and
probably make a workable copy. I'm guessing that key tolerances can't be
terribly close. My worn keys are visibly different from the good one (10 to
20 thousandths off, I'm guessing) and still 'sort of' work. Even high
security locks (Medeco) have been hacked by people with a photo of a key, a
piece of stiff plastic and an Xacto knife. So we're not talking precision
What would help (if its available) is the manufacturer's specifications for
the key blank and pin heights. I'm not a locksmith, but I'm guessing that
the pin heights are set by some integer value times an offset in mm, or
based upon a lookup value. If I had this, then I could correct my
measurements to the nearest correct spec value. Otherwise, I'll just cut
the key to my measurements.
So, my question is: Where might this info be available? I understand that
high security lock manufacturers don't release this kind of info on a
non-restricted basis. But I'm guessing that a 1979 auto isn't exactly the
same as a safety deposit box.
Any other advice would be appreciated as well.
13 years ago