News from the new guy
I hit the jackpot. All three of my Yale Bicentric padlocks are dual custody. It takes both keys to operate the lock. The master (UM2004) only moves about 20 degrees and allows the operating key to open the lock. Both key ways are key retaining. I used a 997ER blank for the master and a L1003M (CO 105) for the operating key. I had to remove about .017 from the height of the operating key to get a good fit. I filed the base of the key, not the pin side.
Both plugs contain odd pins, not Yale standard and a few have been filed down to fit. This leaves a sharp right angle on that pin and the key has to be very close to operate the plug.
When I thought I had found a hard false set on the master plug, it was really picked. I should have left it there and then started to work on the oper plug. If the master plug is not turned first, the oper plug will not move enough to feel any pin at the shear line.
There were only 2 security pins in the lock. A lower pin that had been filed down still showed a single ring around the top. That was not a problem. The other plug had such a pin too but it was not a problem either.
The master key does operate a 3 locks in plug marked UM2004. I will have to shim and open the other two locks so I can make operating keys for them. That will keep me busy for awhile.
Since this seems to be a rare pad lock, I took several photos of the insides so anyone can see how it works. I have posted them on photobucket and this is the link....
http://s24.photobucket.com/user/escapen ... 2.jpg.html I look forward to comments and will be happy to answer any questions that I can.....
Steve