Introduction: How Combination Lock Works? I Made It at TechShop.

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Background:
     Many are curious on how safe are these combination locks?  Does it take an expert to unlock these combination locks?  How does combination locks works?  How can it be improved and become hack proof?   This instructables is inspired by youtube video "Easily Hack a Combination Lock" http://www.youtube.com/watch?v=V9ICkEGCWf4 ,
     Years ago, I had open 3 & 4 digit combination locks by pulling the stem and rotating each digit and feel for the 'click'.  Having know this, it alleviate my fear that I could one day forget the combination, especially when in an emergency situation.  
     At TechShop, I was trying with the rotational combination lock and I was shown the above video.

Investigative Works:
      To understand the inner mechanism of the combination, we need to carefully open the back side.  The pictures show the milling machine setup procedure.  Once the back is opened, we could then analyze the components and better understand the mechanism.  And also how this combination lock was hacked as shown in the Youtube video.
      If you search Youtube, there is over a dozen videos showing the flaw(s) on these combination locks.
      To make it even easier to understand, I would make the rear assembly make out of transparent acrylic. 

Making Combination Lock Hack Proof:
       Can we make it be done?   Let's race to find solutions.   Hurry.  Be the 1st person to solve the problem.  Be the persons to find the best or the simplest solution.

Acknowledgement:
      DC Steve showed me the Youtube video and how to set up the Milling machine to hold a round object and using the indexing table to rotate the work piece.  DCs at techShop continue to amaze me with their bottomless depth knowledge of almost all questions that I discussed with them.