Consistent problem with multiple 7-pin tubular locks

[samcam07012]

I recently decided to try a SouthOrd 7-pin pick. I used a standard tubular lock to practice on. It went fine. Then again. Then when I tried it the third time, it got stuck 90º in the open position. I examined the lock and it looked like the pin that was now lined up with the top slot (for the ridge of the tubular key) was "loose"--if you turned the lock forward and back it would just slide in and out under no tension. I thought I must have compromised the spring behind that pin. So I ordered another of the same lock and chalked it up to experience.

That lock arrived today. This time on the *first try* the same thing happened. Opened, stuck there. So I decided to saw open the first lock and see how the springs worked and what the stuck spring looked like. Lo and behold, of course that "loose" pin was the only pin that there was no spring remains behind when the lock is turned 90º open. It was a "slave" pin and the master pins and the corresponding springs were all alive and springy and well and none of them were lined up with that "loose" slave pin. So I have the pick tightened down to the correct configuration that opened the lock this time, but it definitely does not reopen. I used the Dremel to file off the key that came with the new lock to see if that worked different but wound up splitting the key (cheap key, I'll say to save face) in the process. What am I missing here?

[samcam07012]

p.s. I've turned the lock upside down in a vise and tried pushing in the pins one by one below and applying steady tension to the cam. I've gotten up to about five pins that seemed to engage successfully, meaning the front/slave pins went limp, but the lock still doesn't turn at all. I assume this would be the case even if I got all six pins (aside from the floppy pin without a spring behind it) properly engaged. I am sure I'm missing something obvious here, but my understanding of tubular locks is not great so hopefully someone realizes the obvious solution.

[Raymond]

You haven't broken it, you just dont understand what has happened. It is behaving normally. You were not.

A seven pin lock actually has 8 spaces, The space with no pin, top, center, "0", whatever you call it, has no hole drilled under it and no spring or top pin. When you turned the core it locked up again only the "0" position of the plug has now moved oven a top pin and spring that cannot lock it up. The bottom pin now over the 12 o'clock position now has no top pin or spring under it and is what is termed a 'dead' pin. The lock is now locked with only 6 of the 8 spaces instead of 7.

If you reset your pick, tighten the nut, and push it completely on to the lock you will 'set' the 12 o'clock feeler at the correct depth for the pin under it. Zero the other feelers and pick again to turn the core back to the original position.

When picking these locks, as soon as you have JUST picked it and before turning to the next pin where it can lock up, stop. Remove your pick, zero the feelers, tighten the friction ring and carefully push down on the lock. The tightened feelers will conform to the exact key bitting and your pick becomes the key. When customers have lost their keys, I perform this example and then use my pick as the working key to cut a duplicate. The duplicate becomes the customer's new working key.

Optional fix: If you have a key gauge or micrometer you can gauge your working key and then place each corresponding feeler on the pick to the same depth. Tighten the friction ring and turn your lock plug back to the "0" position.

[samcam07012]

Thanks for your patient and thorough explanation, Raymond. This clarified the matter and solved the problem.