Pick gun design questions ....

[Magic1]

I sit here thinking about the design pf an electric pick gun to achieve the quickest unlock time. Originally I thought that raking might be the best approach, rather than a vibrating needle which may only touch one or two pins at any instant in time ... and the whole process relies on a completely random stimulation of the pin sets, with random results. Several insertions / removals of the needle are required in order to stimulate the pins in the binding order, from a random stimulation. This method relies on finding the pin binding order and trapping out binding pins as they are found ... until all pins are clear and the cylinder turns, under pressure form the torsion tool.

I am wondering if it is possible to avoid the random situation and go for a 'one strike and the lock is open' situation, in the same way as bump keys work. Ie, the same amount of energy is applied to all pins, at exactly the same time, in order to clear all pins from the shear line at the same time. I think the first strike is the only time this would be possible, key pins have different masses, pin springs etc, have a tolerance spread and this causes the 'flight' of the pins to get quickly out of phase with each other and we are back to the completely random situation, where an 'infinite number of strikes are required to find the situation where the pins come back into phase with each other as they bounce.

I would like to make contact with anyone interested in this problem ... if problem it be !.

[MacGyver101]

I am wondering if it is possible to [...] go for a 'one strike and the lock is open' situation, in the same way as bump keys work.

Unless I'm misunderstanding you, what you're describing is exactly how a pick gun normally works (or at least how the traditional, non-electric ones work)?

Perhaps it's just because I'd used a pick gun first... but I've always considered bump keys to work just like a pick gun, rather than the other way around.

[Magic1]

Greetings ...

Since all of the pick guns I have found so far use a swinging needle, they cannot possibly strike all pins at the same time, with the same amount of energy, since those pins closest to the gun are struck with a lower acceleration than those at the other end of the lock. The same applies whether the gun is mechanical or electrically powered.

The pitch of the 'perfect' bump key must match the pitch of the pin sets, in order to all be struck at the same time. With the pick gun it is a much more random process, and even if all pins could be struck at the same time, the swinging arm design, would prevent them all being struck with the same energy.

Pick guns do not work like a bump key ... but perhaps they should !.

Thank you for your reply. It is easy to sit in ones workshop and dream up crazy things, but another to expose an idea and get some real feedback.

jk

[MacGyver101]

Since all of the pick guns I have found so far use a swinging needle, they cannot possibly strike all pins at the same time, with the same amount of energy, since those pins closest to the gun are struck with a lower acceleration than those at the other end of the lock.

Hrm. Interesting. I've always held the (mechanical) pick guns so that the needle was perfectly horizontal when it struck the pins... my thinking being that, in doing so, it would strike all of the bottom pins at the same time (irrespective of whatever angle it may have swung through on the way up)?

The important force should be the initial impulse force that's transmitted through to the drivers, in a similar vein to a Newton's Cradle... so in my way of thinking, it should be the acceleration of the top pins, rather than the acceleration of the bottom pins, that should be the important factor?

Then again, I may be way off in my recollection... pick guns were a curiosity to me a while ago, and I haven't played with one in a while!

[Magic1]

First, I am not sure what I am talking about . I assume that the acceleration transmitted to the driver pins must be in excess of 1 G in order to get the Newtons cradle effect, ie to leave the key pin under the shear line and bounce the driven pins above the shear line ?. The key pins are different sizes and therefore different masses, so I am thinking that the driven pins would only stay together in a 'pack' for a very short time, perhaps only during a single strike. If we add to that the fact that the deepest pins get struck perhaps twice as hard is the front pin, I feel that would also allow the driven pins to bounce 'out of phase'.

What I cannot work out with logic, is how much worse is a swinging needle over one that strikes all pins at the same time and with the same force, ie moves up and down at exactly at right angles to the pins axis.

If we used a DC motor to drive the needle then there is another variable and that is the velocity of the needle. It takes time for the speed of the motor to build up from zero to the maximum RPM. During the early part of the cycle when the acceleration of the needle is less than 1 G, we do not get the newton cradle effect, but the pins do start to move, probably in an out of phase manner, which would prevent a one strike opening of the lock. If one the other hand we used a solenoid, then the variable becomes a constant because all strikes are the same, providing we allow a settling period between strikes.

I am putting together a test rig at the moment which will be micro-processor controlled, to try and find out what actually happens in practice. There are a lot of vaariables involved so I am trying to add some adjustment to each of those. For example I can control the force generated by the solenoid over a range by pulse width modulating the solenoid drive current and frequency. Imay also be possible to vary the speed of the solenoid stroke with a dashpot as well as stroke length. I am trying to take out the human element, because if anything is going to happen it will probably be within less than 100 milli-seconds. So I need to be able to measure the time to unlock in milli-seconds.

The reason I posted this question is because I have only been looking at locks for a very short time and realise I may have missed something important that needs to be included in the tests. Someone did suggest that the pins bounce up and down wildly after a single strike (shown by high speed photography) so I need to find out what the settling time is, in order to be able to use it in the micro-processor program.

jk

[Magic1]

I am doing some 'thinking out loud' here, so please excuse me.

"The important force should be the initial impulse force that's transmitted through to the drivers, in a similar vein to a Newton's Cradle... so in my way of thinking, it should be the acceleration of the top pins, rather than the acceleration of the bottom pins, that should be the important factor?"

Newtons Third Law of Motion .... For every action there is an equal and opposite reaction. I am starting to have problems with this when applied to the striking of the key pins, either with a bump key or a pick gun needle. In the ideal case the key pin is stuck with just enough energy to cause a quick impulse of energy to strike the key pin. The key pin transmits all of it's energy to the driven pin and knocks it above the shear line against the pressure of the return springs, while the key pin remains below the shear line, in accordance with Newtons third law ?.

I think the bump key situation is very similar. The hammer imparts a quick, short displacement shock to the end of the key. This energy is translated through 90 degrees, by the angled flank of the key bite and the key pin imparts this energy to the driven pin as above ?.

OK if that is the ideal case, what is happening with too little impact force, or too much ?. If the acceleration is below one G the key pin bounces up a little along with the driven key, but the pins do not clear the shear line and the lock does not open.

In the case of the bump key, the key has mass and therefore inertia and wants to continue forward after being struck, however the resistance of all the pin sets on the key quickly brake it. The big limitation of bump keying is using too much hammer and the mass of the hammer, instead of imparting a very quick shock to the key ... overdrives it ... forcing the key pins up the flanks of the key bites and onto the shear line where they get jammed.

It seems to me that there is a very narrow area where the conditions are right and the lock will open. Since the optimum operating point will vary from lock to lock, any stimulation of the lock must also vary over a wide range in order to find the condition, where all pins can clear the shear line. Ironically enough a motor driven pick gun automatically does that by going through the RPM range from zero to maximum, but more often than not, the lock still does not open after a single RPM scan, because it is very difficult to strike all key pins at the same time and with the same energy, with a swinging needle.

I am wondering why people persevere with a hammer, when they could use a calibrated mechanical striker and get rid of the human error in bumping ?.

A bump key does allow all pins to be struck at the same time and with the same energy, so I think the pick should be a bump key, instead of the needle .... operating in the lock, with a reciprocating motion, but one cannot use a motor to drive it because of the dwell time required to allow pin bounce to stop, so I am back to micro-processor control again, which is no problem.

The question I am asking myself is why bother to go to all this trouble ?. I think it has something to do with locks that cannot be opened with current pick guns. Then again, what would an old man know about it Hi!

[MacGyver101]

I am wondering why people persevere with a hammer, when they could use a calibrated mechanical striker and get rid of the human error in bumping ?.

Interesting question. The earliest record that I could find on bump keys is this patent, originally filed in 1925:

Patent 1,639,919: Locksmith's Instrument to Open All Standard Makes of Cylinder Locks

The inventor (George Baron) uses a calibrated, spring-loaded striker -- presumably to achieve the exact sort of consistency that you describe. I suspect, though, that factors such as cylinder wear, lubrication, etc., mean that you'd need to recalibrate for every cylinder you encountered... and, at that point, just varying your strike pressure slightly with a hammer is probably faster.

[unlisted]

Please do not create new threads when there is a thread already on the subject.

viewtopic.php?f=1&t=47385

[Magic1]

Strange ... I didn't see any other posts on the dynamics of pin 'flight'. I do apologise and will refrain.

Thank you very much MacGyver101, for your replies. It was nice talking to you. I had a look at the patent that you kindly sent, it looks as if his device is setting up the 'bounce' condition and still requires to be hit by an external hammer. It is a very interesting approach and does cover many points missed by today's 'designers'.

Yes I am sure that conditions will vary from lock to lock and that is one of the reasons I think an automatic stimulation must vary over a range that would include the characteristics of all locks and in my mind it needs to be micro-processor controlled, again to eliminate the human element. Two days ago I made up the basic mechanical side of such a device and now need to build the electronics side, which will basically be a PIC micro-processor switching a power transistor, to operate the re-wound solenoid. I see that something like this is already being sold for about £1000 but is motor driven and rather limited in what it can do.

[edit-not appropriate on this forum]
jk

[amine]

Hi, I'm new on this forum and I'm experienced with electric picks and bump keys. The reason I 'found' this forum is, after searching all posts, I believe I met people who think about this(I explain 'this' right away) the same way I do. As an example, on a german website they offer an electric pick gun with 'microprosser controlled multipick' for a rip-off price like €1000 or so. I've been busy constructing/computing MIC/PIC to integrate in my previously bought elcetric pick. I wondered if any of you guys have similar projects running and I would love to swap some thoughts etc.
I'm very much into chemistry and after a lot of trail and error I succesfully use some types of polymere as a pick in an electric pick, just as strong but NO damage to the pins.

[vov35]

would you not achieve your goals by simply modifying a pick gun to have a sliding rather than swinging motion?

[amine]

Well, it's little bit more complicated then that I'm afraid, but thanks for your thoughts. I'll explain here the best I could, but the best way of course is showing my pics of my process so far, but for reasons I won't place this pics straight on the net, I always want to email or pm or something secure..
Anyway, there is this awesome device from http://www.multipick-service.com/htdocs ... ontrol.php but it's quite expensive. I really would like the electric scheme from it, but they are not that customer-friendly to post it So I'm building and experimenting but not with the succes I already hoped for, but I keep continue. If you have any suggestions they are very very welcome. Okay and before you all think "another new person here thinking he's ...etc" I'll share one of my favorite 'discoveries'.
Anothertime, when I was practising/enjoying my electric klom gun, I experienced that the parts are really cheap, eg they break very quickly and they leave this 'crome' like waste all over the place. So I bought a replacement kit and it was broken in no-time. So then I tought I going to make them myself. To shorten the story a bit, I made needles out of very though steel, BUT now the locks got dameged. And the (excuse my english) 'inside gearbox' of the klom wasn't happy either becaue of the brute force. So, and now comes the reason why you've been reading, I started experimenting with polymers. Because of my profession I could test a wiiiiide range of polymers and finally I 'found' one (to avoid misunderstandings I'm not cooking them up myself, just order them at chemical corp) I finally found one type/blend of polymer which is nearly strong as steel BUT flexible and also stiff enough and can absorb the right amount of kinetic energy Now after discovering this material I had a hell of a job injection molding it (try and find a mold or ask a moldmaker...) but I succeded!!! And now my KLOM with the 'plastic' picks are a gift from heaven. Here a link about the injection molding if that was something new. http://en.wikipedia.org/wiki/Injection_molding
I'm interested in your opinion, I Will Nor post the exact polymerblend on the net, but I'm more then happy to tell you everything about it on secure mail. And I'm very interrested in electric scheme behind the multipick-control. And I also would like to discuss some other quite clever ideas.

[timy]

amine - i like that you have designed a plastic pick, how does it go damaging the point of the pin? Does it transfer all the same amount of energy right through to the deepest pin? When tightened into the pick gun does it stay tight or loosen over a short amount of time?