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How to Make a Lock Bump Proof?

PostPosted: Mon Oct 06, 2014 8:44 pm
by Papa Gleb
Hello pickers,

I believe I read every thread about bumping and anti-bumping as well as googled and youtubed it but my question is still un-answered. Does anyone know or have any idea how to make a lock bump proof or at least not too easy to bump proof? If there is even a way to make a home brew bump-proof lock.

I was donated a pretty new Schlage deadbolt which appears to be more commercial use than residential. I plan to install it into my front door so I took it apart and surprise surprise, a 6 chamber lock is only pinned to 5 so of course added the 6th stack, added security pins (thanks Jeff) and got a SC4 key but then a thought came to mind to make it bump proof or at least make it as hard to bump as possible so any idea, thoughts, comments are all very welcome.

Re: How to Make a Lock Bump Proof?

PostPosted: Mon Oct 06, 2014 8:55 pm
by xeo
One method is to take one of the chambers and permanently elevate the keypin higher than the rest so a bumpkey would not contact it and therefore the bumping principal would not apply.

Re: How to Make a Lock Bump Proof?

PostPosted: Mon Oct 06, 2014 9:11 pm
by jharveee
http://s1155.photobucket.com/user/Altashot/story/82917

Saw this awhile back and i thought it would be a good way to prevent bump keys from working.
I know I would have know idea "WTF" was going on!?!

Home made Restrictive Key way. :akimbo:

Re: How to Make a Lock Bump Proof?

PostPosted: Mon Oct 06, 2014 9:49 pm
by VancouverSpecial
xeo wrote:One method is to take one of the chambers and permanently elevate the keypin higher than the rest so a bumpkey would not contact it and therefore the bumping principal would not apply.


How would this work?
Cheers,
Sean

Re: How to Make a Lock Bump Proof?

PostPosted: Mon Oct 06, 2014 9:52 pm
by huxleypig
I have seen what Xeo said - making a key pin deliberately sit higher than the rest. The UAP Euro lock does this...but all you need to do is have 5 (or 6, depending on the number of pins) different bump keys (with the same profile), with a raised cut for each pin. You then need to identify where the higher pin lives before bumping as normal (using the correct bump key).

I know UAP also put a 10 cut (the lowest) right next to the undersized pin too, and they put an extra strong spring in that 10 cut, both to counteract bumping.

They also sell some squirty liquid that is supposed to prevent bumping but I hear that sucks balls.

Re: How to Make a Lock Bump Proof?

PostPosted: Mon Oct 06, 2014 9:57 pm
by GWiens2001
How about a second driver pin? Put in the normal key pin and a driver pin that is too tall for the shear line with the pins at rest, then a short master wafer on top under the spring. The kinetic energy should transfer primarily to the top pin, which still will not leave the shear line cleared. That, in theory, would make the key work normally, not affect picking, yet reduce the chance of the lock being bumped.

Don't really bump locks, so it is an idea not tested by me, but if someone tries it, let us know how it works.

Gordon

Re: How to Make a Lock Bump Proof?

PostPosted: Mon Oct 06, 2014 9:59 pm
by overWeight
How about threading the pin stack chamber?

Re: How to Make a Lock Bump Proof?

PostPosted: Mon Oct 06, 2014 10:45 pm
by Papa Gleb
WOW gents thank you all sooo much. Great ideas here.
I never bumped a lock, ever made a bump key or even put any thought into it but once it came to my front door I started to read and read and am pretty interested it in now especially since I have no more locked locks to pick :(. Till I get more locks Ill check out bumping just for the fun of it.

Xeo, any idea how to make a key pin stick? I see what you mean but I can come up with any idea how to get it stay at a position.

Harvee, great find mate, that is a pretty nice idea and doesn't seem it would take much time plus you can still use that key to make copies etc.

Gorden, I def want to give that idea a try. Ill let you know if it works. Im just thinking the wafer may not be heavy enough, that the force of the bump may rise the driver and wafer.

Overweight, threading may also work especially with some security key pins, hmmm.

Instead of thinking how to make my lock bump proof, I know am thinking which method to try lol. I will keep you guys posted on which method works.

Re: How to Make a Lock Bump Proof?

PostPosted: Mon Oct 06, 2014 11:48 pm
by jones
Ilco makes a "Bump-Stop" part, but I never tried it

Re: How to Make a Lock Bump Proof?

PostPosted: Tue Oct 07, 2014 2:22 am
by Altashot
I started reading and was going to post a link to my thread, then I saw jharveee beat me to it LOL!

Years ago, I used to work with a lot of Zeiss Icon locks. They had tiny ball bearings inside the springs...
I asked my boss (at the time) Why? He told me it was to prevent "rapping", which is and old word bumping, more or less.
The idea was that the tiny balls would bounce back with enough force to knock the top pins back down into the the plug's pin chambers.

I never tried bumping Zeiss Icon locks and picking them was beyond my capabilities then. These lock were made with such tight tolerances
that they couldn't even be shimmed. Even the thinnest shim wouldn't fit.
The keys were not duplicated either, all were originals, cut on a Framon or Borkey machines. If the keys were out by 1 thousandth, they were "clicky" in the lock.
When they were perfectly cut, you could blow on the bow and the plug would spin...

That was German quality.

M.

Re: How to Make a Lock Bump Proof?

PostPosted: Tue Oct 07, 2014 3:57 am
by escher7
Medicos and other "twisty pin" locks are bump proof unless the guy has studied "Open in Thirty Seconds" and even then.... Not likely the thief would be that sophisticated. And then there is Abloy etc.

Re: How to Make a Lock Bump Proof?

PostPosted: Tue Oct 07, 2014 5:44 pm
by Papa Gleb
Altashots, great work on that anti bump feature. I am leaning a lot towards that idea plus get a cool custom looking key out of it. If not counter milling the chambers then this is what I will go with. Already been thinking what to use as that metal piece. Most probably will use the same hack saw to cut the plug and make that piece.

The ball bearings idea sounds like it would work but it also sounds like a nice mission finding such small balls.

Escher, I already have a Medeco (if that is what you meant) mortise installed but in a POS Adam Rite so I dont except it to hold up to too much force against a pry bar and I have this Schlage deadbolt. My neighbor's apartment was already broken into using a pry or crow bar and with a single lock my door is asking for it.

Re: How to Make a Lock Bump Proof?

PostPosted: Wed Oct 08, 2014 1:26 am
by huxleypig
Try the different strength spring thing too,that might help.

I seen a tubular lock bumped in the past and I know ACE II and similar use different strength springs. I think this is more of an anti-impressioning feature.

Re: How to Make a Lock Bump Proof?

PostPosted: Wed Oct 08, 2014 1:48 am
by jones
huxleypig wrote:Try the different strength spring thing too,that might help.

I seen a tubular lock bumped in the past and I know ACE II and similar use different strength springs. I think this is more of an anti-impressioning feature.



It's an attempt to make them pick proof, the way an ace lock works you can't prevent a pin from binding,
so making impressioning stop working should be impossible

Re: How to Make a Lock Bump Proof?

PostPosted: Sat Oct 11, 2014 3:31 am
by plugspin
jones wrote:Ilco makes a "Bump-Stop" part, but I never tried it


Technically "Bump-stop" is Master's anti-bump system but it only works on Master and American locks due to the smaller diameter of their pins. Ilco's product is called "Bump-halt". This consists of a much stronger spring and a strange looking light weight driver pin. If anyone uses this I highly recommend using at least two per cylinder. I've had intermittent success bumping open test locks with a single bump-halt pin, but two or more I've never had success with.

You could also try doubling-up the springs on some pin chambers, but I've not tested that. There could be unforeseen problems like the spring getting caught and drawn into the sheer line when the plug turns.

http://bit.ly/1svZZU2