Bump Key question .. need input please

[keysman]

I have been bumping locks successfully for about 5 years.. right after the original document from the TOOOL (?) site became public.
I have bumped most pin tumbler locks that I run into with little or no trouble .


I have since seen some of the videos that are around the web, featuring Barry Weils (sp?) and Han Fey giving a demonstration on bumping various locks.

Recently Barry Weils (sp?) and Han Fey were in Las Vegas for the ALOA convention,
They needed some bump keys and some locks for a demonstration they were making at the convention and had made arrangements with me to provide them .

Barry had some new Bump Hammers( like the key-bump) he wanted to try on the locks I provided,

He filed the tip and shoulder of the key a little bit and bumped the lock immediately .

When I asked about the filing on the key, he said that is the way he always does it…

My method is to cut a key on a code machine to the deepest factory depth and use it without any modifications .. I don’t cut the shoulder back, I don’t cut the tip back , I don’t widen the cuts and I don’t cut deeper than the published factory depths….

We tried his bump hammers using his “cut back “ method and my “out of the box “ method with no significant difference .. both methods worked exactly the same … lock bumped open in 1 or 2 tries.

We then tried my ‘hammer handle “ vs the Bump Hammer.. I have to admit the Bump Hammer was more effective.

The question here is ….. does anybody else just bump locks with “out of the box “ keys , and if not ,do you see any significantly different results by making the “common “ modifications to the keys???

I can understand making a slightly deeper cut for the possibility of a # 9 pin , but I am not sure I understand the point of the other modifications.


Thanks for your comments

[Raccoon]

Bumping works, not by allowing the pins to rest at the lowest depths of the key, but by having the pins strike against the edge of the cuts where it tapers upward. In order for it to strike these cuts, the shoulder of the key must be cut back 1/4 to 1/2 of a milimeter. The tip is usually cut back aswell to prevent the tip from hitting the inside of the lock as it goes in deeper than designed.

A good alternative to cutting back the shoulder and tip, is to cut-forward the key when it's being cut. Insert a 1/4 to 1/2mm spacer between the shoulder and shoulder-guide before cutting the key, and the cuts will be forward enough to allow the key to strike the pins when inserted fully into the lock.

This method of bump-keying is called minimal motion method. See section 3.1 of Barry's "Bumping locks" PDF writeup. It is far more effecient than pulling the key back one full bite before bumping it in. Rather than bumping the key a 1/4 inch, it need only move 1/4 a mm.

[Raccoon]

PS. I would like to know how you were bumping locks 5 years ago. "Bump Key" wasn't even coined until 2004, as far as I can tell.

[zeke79]

Bump keys have been being used for much longer than the TOOOL papers reporting about them. TOOOL simply made the method famous by showing its effectiveness on high security locks.

keysman,

As far as your method goes, are you using a standard cut key and pulling it out one space before striking? My all time favorite method of making my bumpkeys without filing is to place them in my key machine and using my predetermined shim stock offset the key in the vise. This effectively moves all of the cuts toward the tip of the key simulating as though I have removed material from the shoulder but my spacing always remains true. The keys alway come out consistent in this manner.

[keysman]

PS. I would like to know how you were bumping locks 5 years ago. "Bump Key" wasn't even coined until 2004, as far as I can tell.

I just did a search on Clearstar for "bump" where I think I orginally heard about the method.
Lots of Posts going back to mid 2000, Don't know where you discovered the info in 2004, but the information has been around publicly( internet ) since mid 2000 anyway.

This method of bump-keying is called minimal motion method. See section 3.1 of Barry's "Bumping locks" PDF writeup. It is far more effecient than pulling the key back one full bite before bumping it in.

I have to disagree with you here.. tests with an "expert"
using the same lock and 2 different methods produced no significantly different results..... easier maybe, but certainly not more effective.

effecient??? We are talking about moving a key less than a 1/4 in ( with a hammer!) How much energy are we talking about saving here?

keysman,

As far as your method goes, are you using a standard cut key and pulling it out one space before striking?

Yes, pull it back one notch ,it works so well I have never tried to "improve" it.

[Shrub]

If your pulling back one space then thats why youve not had any problems at al,

The technique you use was called rapping and has been around since the early 90's i think, it was toool i think who coined the phrase but i could be wrong, i think it was being banded about as that name from 2000 as said maybe even a little earlier,

[Raccoon]

Have you ever considered using a precise measurement of shoulder spacing to match the kerf (cut) width of the key in question?

Assuming the pins are pointed, you would want to move ahead the spacing in conjunction with the kerf width of the biting so the tip of the pin only barely strikes the cut slope between bitings. Another key would be made should the lock contain flat-bottom pins, such as Kwikset (and Yale?) do, so the pins don't jump too far up (being wider).

I have heard suggestion of using a rounded cutting wheel that leaves a curved slope instead of a 45° slope, causing even less contact with the pins over a greater distance of strike, and preventing the peaks of the slope from extending above 999 (if cut at 10,10,10). This can increase longevity of the bumpkey as the pins are less likely to impression the curved slope, and provide better results for really low cut keys.

What do you think?

1000th post.

[Raccoon]

Yes, pull it back one notch ,it works so well I have never tried to "improve" it.

When you pull the key out one full notch, the slopes in the middle of each notch can extend 2 full spaces higher. If you have lots of really low pins in the lock in question, they will fly above the shearline and the bump will fail. You merely lucked out.

TOOOL doesn't have any papers dating back as far as you suggest. Their earliest paper on bump keys is 2004.

[Shrub]

I thought kerf was the offset of a cut,

Toool may not be the ones i am thinking of then but it doesnt mean they wrote a paper on it as soon as they found out how easy and effective it was, one of you should pm Barry and ask if he has a definative answer of when bumping was called bumping, personally i have litriture dating back to the early 90's that explains the technique in detail but called it rapping and they said it was a forgotten technique so i guess its older than that,

[Raccoon]

I'm just referring to keysman's own words.

I have been bumping locks successfully for about 5 years.. right after the original document from the TOOOL (?) site became public.

Additionally, I have a feeling he's defending his method of "factory specification" cut bumpkeys, because we had an argument over PM over this exact thing. He has a website where he sells bumpkeys to the public, and I called him out on how he glamorizes "unmodified" when this is actually a drawback.

Assuming I read the topic title correctly, I thought keysman wanted some input, but I'm only sensing a wall of defense.

[Shrub]

Ah i see, ill stay out of it then,

For my opinion the method of trimming the tip and shoulder is a better one but Zekes is the best, the pull back one method can damage the plug face too much if done too often,

My personal preferance when ive played with the idea is to remove quite a bit off the shoulder and some of the tip, i then insert the key to a lock and set it correctly then cover the area where the key enters the keyway in hot glue to act as a buffer,

This leaves zero marks on the out side of the lock no matter how much you do it,

[Shrub]

Im also with the idea that pulng back one can overset low cut pins, it must surley reliy on over setting them and then getting to shear when they drop back,

Is constant tension used on the pull back method when you do it or turn at the right timing?

I imagine the reconised latter method as a constant tension would cause more problems if the pins are over set,

[Shrub]

Sorry about this

I do however think that the pull back method must be a better method if there are mostly hight cuts in the lock as the 'bounce' will be greater,

I have not used the pull back method, i tried it twice but it didnt work for me, i have tried bumping as per the other way and have got it to wortk but i am in no way well versed nor praciced on the technique and i dont use the method for work so these are just my opinions that i cant back up other than theory,

[keysman]

My personal preferance when ive played with the idea is to remove quite a bit off the shoulder and some of the tip, i then insert the key to a lock and set it correctly then cover the area where the key enters the keyway in hot glue to act as a buffer,

This leaves zero marks on the out side of the lock no matter how much you do it,

I remember that idea being posted, sounded like a workable idea Thanks , I will have to give it a try. Do you put the glue on all the way around the key or just on the shoulder?

Im also with the idea that pulling back one can overset low cut pins, it must surley reliy on over setting them and then getting to shear when they drop back,

Is constant tension used on the pull back method when you do it or turn at the right timing?

YES , timing is a MAJOR factor, probably more important than anything else.
I equate my use of bump keys to a pick gun.. I believe they both work on the exact same principle... (que ball/ 8 ball anology).

The technique you use was called rapping and has been around since the early 90's i think, it was toool i think who coined the phrase but i could be wrong, i think it was being banded about as that name from 2000 as said maybe even a little earlier,

I remember reading an OLD locksmith magazine that mentioned Raping .. didn't give much information so I never persued it ,
There is a method of opening padlocks ... the kind that have a spring loaded catch ( not sure what the part is called) where you smack it with a solid object to open it , I think that is also called raping.




Thanks for yor input

[keysman]

My all time favorite method of making my bumpkeys without filing is to place them in my key machine and using my predetermined shim stock offset the key in the vise. This effectively moves all of the cuts toward the tip of the key simulating as though I have removed material from the shoulder but my spacing always remains true.

Would that predetermined shim stock be a ??? washer? dime? or perhaps some other common object?


Have you ever tried the 'pull back" method?


Thanks for your input