Effect master pins would have in bumping a lock

[bjornnrojb]

I was just thinking about the oft-used analogy of the little balls on a corporate guy's desk that demonstrate conservation of energy. You let two balls go, two balls on the other side respond. One ball, and one ball responds. I have read that this is not the true metaphor for what is happening in a lock being bumped with regard to the laws of physics, but if you have a master pin that without a key in the lock is resting across the shear line so that some is above and some is below, I would think that bumping this lock would cause the top pin to bounce up but the master pin would stay in the exact same place.
Master pins make picking much easier, but could putting a large .120 master pin in the lock make it unusually hard to bump because of the tendency of the force of the bump to be transferred through that pin and into the top pin??

[cj101]

The analogy with the balls can be very misleading. It shows energy conservation - but not more. Mass spring systems have to be computed using differential equations. Just change the weight of the individual balls, and the beahviour deviates form the typical 'ball gimmick'.

You pins do have different weights. Furthermore, there is a spring involved. There has already been a paper published on the physics of lock bumping. The computation is far more involved, as it might seem:
Lock Opening by Bumping: Physical Analysis and Secure Lock Designs / Alexei Torop

It is not easy, to make a good guess, what you would gain, by introducing master pins. I do, however, not believe, that resistance against bumping is increased by masterpins.

[bjornnrojb]

It's been a long time since college stat class but I will pin up a bunch of cylinders and see if there is a statistical difference in a double blind test. I am also going to try cutting bump keys deeper than the 9 cut to see if I can pull the key out once the lock is turned with 8 and 9 depth pins so I can use a plug spinner.