Updisde down keypins adding bump resistance?

[ARF-GEF]

Hi guys,

I've been playing along with pins today and I had an idea:
if instead of the usual driving pin one would put in a keypin (with the tip touching the bottom of the other keypin* ) we could very much change the way the force is transmitted from the pins in a bumping attack and maybe that could be a very cheap and easy, "DIY" way of adding a bit of bump resistance to the locks.

So I tried it and I found in my mini experiment that it did made bumping less successful for me. I'm not practised in bumping, (it's not really an area of interest to me, so I'm new to it).
Due to that, my trial's non blind nature and the low number of experiments I would label this very much needing further testing but I thought it might be worth putting the idea out there and hearing your opinions.


* : Here is a primitive drawing of what I mean with the pins:

<spring> <first keypin instead of driver> and <second key pin, actually functioning as a keypin>
ssssssss ===> ===>

F(AR,GE)

[mechanical_nightmare]

I have come across locks which were probably serviced by a locksmith, and the locksmith had done the exact same thing you described (replaced the driver pins with long key pins). I never tried bumping those locks, but they picked easily enough. I would give your idea a try, but I really haven't practiced bumping that much, so I wouldn't be able tell if it is because I can't bump the lock or if it is because the new driver pins are stopping me.

If the beveled edge of the key pin doesn't allow a well enough transmission of force from the key pin it should make bumping harder. Perhaps using a key pin and a very strong spring?

Only way to tell would be through trial and error.

[GWiens2001]

No bumping expert, but it seems that if some of the key pins were upside down, then some of the key pins would start to move just slightly before the others as the ramps of the bump keys hit the wider bottom of the upside down pins first, and the pointed properly oriented key pins a fraction of a second later.

Think somebody who is more skilled with bump keys might be able to deal with the upside down key pins without difficulty.

Using a few springs of different strength should be a greater bumping deterrent, no matter what the pin orientation.

Gordon

[ARF-GEF]

I think I wasn't too clear I meant all teh keypins are the right way up, but 1 or 2 of the driver pins are changed to keypins with the point end facing /UP if you are in Europe and / DOWN if you are in the US/.

[GWiens2001]

It seems to me that would make picking easier, though, as the pin gap at the sheer line would be wider at the edges.

Gordon

[ARF-GEF]

True, very much so.

[danfordman]

So in theory It makes sense that if the tumblers can't fall due to the upside down placement the bump key method would not be applicable, in the way you tube videos make it out to work anyway. I could be entirely off base but it would seem the person attempting to bump key the lock cylinder would have to revert to more traditional lock picking methods. Am I alone in this thought process or does it make sense?

[bjornnrojb]

That is a trick used by locksmiths to masterkey a cylinder when they want to make sure that any depth will work for that chamber. It might be used instead of a .015 top pin, which can cause problems if used by getting wedged between the plug and cylinder.