Especially if you are picking a lock with security keypins, such as serrated or torpedo shaped keypins. If they are caught overset, It's very difficult (sometimes impossible) to fix it.
But you can avoid these situations!
I was lucky to find a way to do it. First I will share how I do not overset, and then how to try and fix in case you do.
None of this is new! Actually, if you apply the correct technique the books teach, you should do fine. But almost no book focus this in detail. I will try to.
So it all comes down to how you set a pin.
Setting a pin isn't just lifting it while applying tension. This is where the others fail...
Setting a pin is actually a very complex process, that requires practice to master.
Also, light, medium or hard tension are subjective, and aren't proporcional to your rate of success (unless you break your tools, so lighten up your hands ok?
)In order to lift a pin, you have to find a perfect balance between Tension Force and Lifting Force. The concepts are very important!
No matter how much or how little tension you apply, there is a lifting force that allows the pin to be lifted. And a very small window of oportunity to set it correctly.
Let's give it a go. Take a lock (preferably a lock you are conforable picking) and apply no tension at all to it. Use a pick to lift the pins and feel the force it takes to lift them. After that, apply harder tension and find the binding pin (when I say hard tension I don't mean break your wrench in there!). DO NOT lift the binding pin yet!
After you place your pick under the binding pin apply just a little bit of lifting force. It won't budge right?
Now slowly start reducing the tension force untill it starts to lift.
STOP EVERYTHING!
This is what all the books say. And it's absolutely correct!
Now comes the part where you learn how to not overset a pin.
As you noticed, the lifting force is proporcional to the amount of tension provided to the lock. You have to practice REALLY hard how to achieve this balance and mantain it on every situation.
In order to understand this, lift the pin untill it sets. After it sets, continue applying the exact same amount of tension and lifting force to the pin.
It won't overset!
This happens because, uppon a setting, the plug rotates just a fraction, and the lifting force isn't enough to make it go backwards again so the pin can go higher. If you mantain this balance, it's virtually impossible to overset a pin, as there isn't enough force to do it.
This is true for light or hard tension. You just need that perfect balance.
Now if you reduce tension or increase the lifting force it will overset. But you have a window there. With practice you will learn that window and be within it's limits without thinking about it.
A good way to practice is to do this exercise many times, with variable tension. And vary the tension and lifting force WHILE lifting, so you can get a sense of coordination doing it.
Yeah cool but... How do I fix an overset?
Well, for starters, you have to know it doesn't allways work!
And the method is what you are already thinking! Let go a little tension and allow the pin to fall down. If done correctly, when the pin passes the sheerline again, the plug should rotate that tiny little bit, not allowing it to reset completely. It's normal to drop a few other pins in the process. Don't worry about it and just practice.
The trick is just to find the right amount of tension to let go.
In order to practice, you should use a lock you are confortable with and pick most of it. Then, bounce the tension a little without droping any pins. Keep doing it, getting bolder and bolder untill you find that perfect spot; and are able to do it fast.
After that, try real oversets. Reset them. And try to do it faster and faster.
Being fast is not important. But when you practice doing it very fast, you actaully develop the precision needed to do it slowly. The faster you can do it, the more accurate it will be after.
As you can see, I didn't add any new information to whatever books you have read. But I tried to focus something that I don't see much, as it has helped me countless times.
Have fun!
