DIY video of bumped pin dynamics

[Gordon Airporte]

I don't have the fancy high-speed video equipment that Master Lock does, but I think I've managed to simulate the phenomena they saw with a bumped pin stack separating on the way down. Just pretend the stack has been bumped and reached it's zenith, then watch as the nuts standing in for pins come apart.
And if you aren't European, maybe stand on your head while you watch it .

http://www.youtube.com/v/Q7HkdH8BGK4

[Shrub]

I think you had better read the rules,

We dont allow the posting of copyrighted video and this is obviously masterlocks research tape,



I understand the concepts very well and can see what the actual differance is between what masterlock and people like johnny are saying and waht my and a few others argument is,

Its all about the actual point that either side is specifically talking about and if im on a good day this coming week ill sit down and type it all out but basically newtons law is not changed, its still in effect and still working the same as the cradle,

What masterlock and the other bandwagon riders are saying is somthing differant however but some have mis interpreted that as somthign else,

It is very possable and actually more likely that the separation becomes during or after the upmost pinacle of height has been reached in the pin stack, afterall the newtons law dictates that every action has a opposite and equal reation but if you look further into it the first action is lessoned in comparison to the resulting reaction which basicaly means that once the bottom pins have hit the top pins and that they then both travel upwards there must come a time when the top pin has more force in it that the initial bottom pin, with nothing stopping the pin dropping back down a gap can form,

But there has to be agreement that there is surely an argument for the fact that locks have springs and the springs reaction time is faster than gravity can pull that mass down meaning that the spring would surely push the top pin back onto the bottom pin quicker than it could fall away due to gravity (which is the only other force in the equation as a relative object),

As i keep saying i have neither the interest nor energy to argue about such unimportant things as i dont personally care when the pins separate, thats a secondry knowledge but i will challenge the question of newtons law not having any bearing on the situation regardless of in what capacity, if newtons law is not involved in the process of bumping then it simply must rewrite phisics as we know and believe it unless your a trekky then i guess worm holes and helixs are real,

[mh]

I don't have the fancy high-speed video equipment that Master Lock does, but I think I've managed to simulate the phenomena they saw with a bumped pin stack separating on the way down. Just pretend the stack has been bumped and reached it's zenith, then watch as the nuts standing in for pins come apart.
And if you aren't European, maybe stand on your head while you watch it .

http://www.youtube.com/v/Q7HkdH8BGK4

Quite funny, but even standing on my head I don't get it, the spring seems to be on the wrong end...


Anyway, to me the whole problem of people not understanding or believing each other seems to be
based on different assumptions as to how the bump key interacts with the bottom pin.

I think there are at least two options how you could accelerate the bottom pin
(1) by pushing the slope of the key cut through, this will move both pins at the same time
(2) by just hitting against the key but not moving it (just a tiny little bit), this will create a collision between the pins and the upper pin might fly upwards.

I wrote a page about (1) on the other thread, but then there was a lot of drama and it became locked...

Cheers,
mh

[Shrub]

If decent discussion is made its a good subject (not bumping but the dyamics behind it) but when emotion comes into it things do get locked,

Well there is as you say two ways to bump, the pull out one cut and hit is the older way with the key fully in and hit being the newer way,

If the method used was the pull out one key method then the pins will create a gap on their way down as its not really properly bumping and more akin to overlifting with careful tension,

Having a key fully in the lock and only 0.5mm of movement in or out on the slope of the key cut will not lift the pins any higher than 1mm (AxB=C) if on a 45' angle, this is not enough to rise pins above the shearline,

I couldnt see anything on the video and thats what i found amuseing but im not sure if its a serious effort of not hence i didnt comment,

You also have to ask how a cut away lock reacts as its bumped and if it acts the same as a whole one, an xrayed lock while bumped would be a better test,

A few years ago i saw a video of the bumping princible, it may have been on the old lss or somewhere else but it was a proper model that had been made to show how it worked,

I havent had time to read the masterlock findings but i assume its simply the counter bore solution? if so i think theres a defeat to those systems by way of special bump keys but thats somthing i will have to research up on as my memory faiuls me as to the exact details but i think it was basd around a key with a higher cut so it sets that special pin certainly a lock with all counterbores is a lot easier to bump as you use a differant type of key to do it (from memory),


Perhaps i should just leave these threads as its not for me but when someone challenges the laws of phisics i want to be invloved,

[greyman]

Thanks to Gordon Airporte, we have a reopened thread on bump key dynamics. OK - be calm everyone and no more personal attacks

Two interesting things to my mind:

1. the idea that the rebound off the top of the chamber makes the pins separate;

2. that there isn't really an argument here at all.

As for 1, I think that there may be a problem but I can't quite put my finger on it. The rebound is being cushioned by the spring and it's not the same as the initial impact from the bump key. Energy is being lost all the way along due to friction, etc.

As for 2 - the phrase "separates on the way down" might just be a loose way of saying (as another poster said on the original thread) "separate while bottom pin is on the way down". Now Billy Edwards's statement, as quoted by whiteknight38, makes it clear that the top pin has not yet started to descend. This is a very important point and one that, I think, has caused a lot of confusion here. If the top pin is not yet descending, it is either still on its way UP or (less likely) instantaneously stationary. The first option seems perfectly feasible to me. The problem with the earlier loose statement is that is conjures up a mental image of the lower pin accelerating away from the upper one as they are both falling back down, having been previously in contact. This can't happen unless there's an extra downward force on the bottom pin (which there isn't).

One further thing. The frame rate was about 2000/second and the bump dynamics occupied only 15 frames. I would hazard a guess that it is pretty hard to say from the photo data where the top pin actually stops going up and starts coming down (the positional errors in the experiment would only make this harder to judge since you are trying to estimate tiny differences in position as the top pin slows to a stop then starts up again). I reckon it would be much easier to spot the appearance of the slight gap between the pins (when they start to separate) than the moment where the top pin starts moving down.

I hope I have lessened rather than added to the confusion with this post.

cheers

greyman

[Gordon Airporte]

I guess I hadn't thought hard enough about the risks of reopening the issue, but everyone is staying cool so that's good.
It looks like the only two possibilities are that
1. The bottom pin stays put or moves only slightly on the ramp and the top pin jumps.
2. The pins go up together and the bottom comes down first, creating a gap.

I think 1 is the 'classic' Newton's cradle/pool balls view of how it works, with the energy transferring through the bottom pin entirely to the top which allows the plug to turn any time the top is above the shear line. This might be true of pick guns but not of bump keys because of the ramp, which might complicate things, as mh noted.
2 confusing me more now. I played with my model some more and I think my fat fingers may have obscured the dynamics. If I grab only the top or bottom nut with pliers, pull down to compress the spring, and release, the gap does not appear. The gap appears if I flick down on the top nut and the nuts bounce back. I'm still trying to figure out what that means as applied to a lock.

[ObiWonShinobi]

After a certin amount of FORCE is generated,
The midichlorians take control.

Direction is futile..... you will be bumped.

[ObiWonShinobi]

Hey shrub, all joking aside...
I found an ACTUAL video from Masterlock Co.'s
Research and Development dept.

please dont ban me for posting this.......

http://www.youtube.com/watch?v=4aenzUIi ... ed&search=

[Gordon Airporte]

Hey shrub, all joking aside...
I found an ACTUAL video from Masterlock Co.'s
Research and Development dept.

please dont ban me for posting this.......

http://www.youtube.com/watch?v=4aenzUIi ... ed&search=

Umm, yeah, wtf? BANNED!