On Tue, Apr 8, 2025 at 5:33 PM Paul Koning <[email protected]> wrote: > > > > > On Apr 8, 2025, at 12:06 PM, Tony Duell via cctalk <[email protected]> > > wrote: > > > > ... > > I think there is only one key. The lock is somewhat unsual though. > > > > There are 4 pins in the plug (the rotating part). There are 3 > > positions of the lock and the key is removeable in all 3. There are > > therefore 3 sets of upper pins and springs in the housing. The 3 > > positions are 'OFF' (anticlockwise), ON (centre), PM (clockwise). The > > visible holes in the housing were always empty, I've not removed > > anything there. I think they were there to allow the springs and upper > > pins to be inserted when the lock to be assembled. Note that the hole > > for the 'OFF' position are ofset away from the front of the lock. > > > > Here's what I think happens. In the ON position you can use the key > > and simply turn to PM. And go back again But to select OFF you have > > to push the key and plug inwards before turning the key. To turn on, > > you just turn the key (you can't go too far and select PM by > > accident), the plug will then spring forwards. There was a compression > > spring in the back of the lock, forcing the plug forwards. I have > > removed this now for the moment. > > > > The in/out motion of the plug is controlled by a pin (the end of which > > is the silver circle in the 'side' photo) running in a groove in the > > plug. > > That all makes sense. To allow removal of the key there have to be holes at > that position to let the pins (the ones in the cylinder) move upward as the > key is extracted. Then normally the pins in the lock body would be pushed > inward by the springs, locking the cylinder. > > If for some of the positions you have holes but they are empty, it means the > key can be removed in that position, and then the pins would probably drop > back into the cylinder, leaving it unlocked and free to turn. But in > addition, you could turn the lock upside down and let the pins slide out (be > sure to keep them in order). The lengths of those pins would tell you the > cuts needed for the key.
I think all the holes have pins. The confusion arises because the lock is effectively upside-down. As viewed on the machine, the pins are at the lower edge of the keyway, The cut edge of the key goes in on the bottom. The holes on the 'top' are there for assembly. However you do raise an interesting idea. My intention was to knock out the pin that guides the moton of the plug from the other side, or if that's impossible to carefully drill it out. I was then going to pick or shim the lock to free it and remove the plug by pressing it from the rear with a suitable cylindrical follower to keep the 3 sets of upper pins and their springs in place. Then remove the pins from the plug and measure them in order to cut a key. But I could, instead, after picking or shiming the lock simply turn the plug through 180 degrees to line up the pins with one set of holes. And extract them that way. -tony
