Best lock peculiarities?

[sisk]

I've gotten a Best core with no key. I haven't had a chance to pick it yet, but I will at some point in the next couple days. When I do pick it I intend to gut it and make a key. Two if I can figure out how to do both the core key and the operation key. With these being such oddball cylinders with the double shear line and core removal mechanisms, are there any gotchas I need to keep an eye out for while I'm gutting it? Or do you gut a Best just like you'd gut anything else?

[Tyler J. Thomas]

Do you have a way to cap it? That's the only issue. You could tap the holes and install some hex head screws in each chamber like all the cool kids are doing these days.

When ejecting the pins/spring for each chamber, you'll more than likely ruin the springs. It's inevitable really.

Other than, they're pretty simple. Don't bother with the matrix formulas from BEST, it's like using multiplication and division to solve a simple addition problem.

Control Key Cut = 13 - Top Pin Numerical Value
13 - Control Key Cut = Top Pin Numerical Value

Follow basic master keying rules to determine bottom and master pin(s). If no master pins, it's simple.

So, from the above formulas we have the known depths of 2 pins (non-mastered chamber) or 3 pins (mastered chamber). On an A2 system, the total stack numerical value of 23.

From there, 23 - Top Pin - Master Pin (if applicable) - Bottom Pin = Control/Build Up Pin

If you need a visual representation of this, visit my Altering SFIC thread in the Open Source Lock forum. I posted a handwritten chart in there that you can apply these formulas to.

[sisk]

I had to read that twice, but I think I understand it. Just one question. If it's pinned up just like a lock with a master key why is it that you can't mix and match the shear lines like you can on master keyed locks? Or can you? I've not yet picked a Best, just read about them.

[GWiens2001]

Because there are two DIFFERENT shear lines. Mix and match, and the lock will not work at either shear line. All the pins have to be set at the same shear line.

You may wish to read this excellent paper on operation of SFIC locks. before you attempt to disassemble the locks. And I do not recommend tapping and adding set screws on an SFIC lock.

Gordon

[sisk]

Cool, that article cleared things up a LOT. Now that I understand how the things work I've got a handle on how to go about cutting keys for mine. I think I need to make one of those control sleeve tensioners first though. I might go a little crazy with those kind of odds against me getting all the pins on the same shear line.

[GWiens2001]

If you want to make keys without taking apart the core, you might consider trying this method.

Gordon

[Tyler J. Thomas]

Cool, that article cleared things up a LOT. Now that I understand how the things work I've got a handle on how to go about cutting keys for mine. I think I need to make one of those control sleeve tensioners first though. I might go a little crazy with those kind of odds against me getting all the pins on the same shear line.

They don't have to all hit both shear lines at once, just the shearline of the control or change key.

If the change key is inserted, the pins only have to line up with the "normal" shear line. If the control key is inserted, the pins only have to line up with the control shear line.