Expected lifetime on L&F tubularlocks??

[rohi]

Ok, he re we go.
Forgive me for maybe using wrong terminology.

When the student key is placed in the lock, shearline 1 is used.
Due to the nature of tubular locks, the pinstacks cross over each other while the plug is turned.
When the key is removed at any position that is not the starting position, the pinstacks will lock with the wrong top pins, leaving at least 1 pin on the blind spot in the housing.
When the masterkey is than inserted, the pins in the masterkey ring will not be the right pins for the code of the masterkey, and because of that the first and second shearline will be blocked.

This is as clear as i can explain it.
If someone can do better, maybe with a diagram, please do so.

Ronald

[mh]

That makes sense.

But now imagine the other way around - the janitor has a worn-out key and messes around with the lock, removes the key at the wrong position.

In that case, a student key with the notch removed could still work, if inserted in that wrong position, because it uses the 1st shearline, and for that, the second set of pins does not matter.

So it *does* depend on which shearline is used for the master key, doesn't it?
If it was the other way around -as described above-, the janitor could open the locks non-destructively with a modified key.

Cheers,
mh

[rohi]

The situation depends on the pin above the blind spot.
If this is a longer pin, the key will not be able to go in far enough to clear the shearline of the masterkey.

I'll think about this a little longer and come up with a diagram sometime tomorrownight, shootingrange is waiting right now

See ya'll soon,

Ronald

[mh]

The situation depends on the pin above the blind spot.
If this is a longer pin, the key will not be able to go in far enough to clear the shearline of the masterkey.

That's right.
But if the locks always fail in that configuration -1 pin offset-, and the master key uses the 1st shear line, then
1) if that pin above the blind spot is shorter than the pin next to it, you just cut away the notch of the special master key - or
2) if that pin is longer than the pin next to it, you also cut the special master key at that position to the same code as the position next to it (or to a '9', doesn't matter).

All very theoretical, though, if L&F uses the other shearline.

But if not ... - you *could*

Cheers,
mh