What would happen with cone shaped driver pins?

[Richie Rich]

So, I'm a design engineer by trade, (even though I'm a screen printer right now).

What would happen if security driver pins were cone-shaped and very smooth, (think very low friction)?

Put your key in and all pins hit the shear line.
As you apply tension when picking - the driver pins would be forced down onto the key pins, right? Rather than binding

As the first one is set, would you be able to set the others, because you would have to release tension to allow the large base to break past the shear line into the bible every time.

Or would it just work like a normal driver pin, but with much much finer tolerances for picking? Or would it just be the same, or not work at all? I'm assuming the height v's diameter is suitable to prevent the pin jamming.

Thoughts?

[mikus]

You mean sth like that?
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key pin here

I guess they would be easy to pick. Finding binding order would be like in spools but much easier to pick since nothing blocks the pin

[Richie Rich]

Kinda!

But with a normal cylindrical keypin.

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[SnowyBoy]

I'd guess it would give away plenty of feedback. Like the backlash on the cylinder you get when you lift a binded spool, but really precise so you'd know when the pin was set as it would slowly increase the tension of the cylinder until it sets with a click.

[Richie Rich]

I'd guess it would give away plenty of feedback. Like the backlash on the cylinder you get when you lift a binded spool, but really precise so you'd know when the pin was set as it would slowly increase the tension of the cylinder until it sets with a click.

But remember it gets bigger at the bottom too - so does the keyway need to turn in the opposite direction to your tension direction as you lift each driver pin? ie, WOuld you have to reduce tension as you lift each conical driver pin in order to just maintain constant tension?

And then would too much tension force the driver pin back down, like when you squeeze a bar of soap between your finger and thumb?

[GWiens2001]

I'd guess it would give away plenty of feedback. Like the backlash on the cylinder you get when you lift a binded spool, but really precise so you'd know when the pin was set as it would slowly increase the tension of the cylinder until it sets with a click.

But remember it gets bigger at the bottom too - so does the keyway need to turn in the opposite direction to your tension direction as you lift each driver pin? ie, WOuld you have to reduce tension as you lift each conical driver pin in order to just maintain constant tension?

You need to do that anyway for security pins. As SnowyBoy stated, it would make it very clear which was the binding pin. A true mushroom pin (not just a spool pin) looks similar, but where the cone you drew is narrowest, it adds a flat piece the same diameter as the widest part of the pin. Then it is mounted with the narrow end of the cone facing the key pins.

Here is a picture of the pins from a Banham cylinder. The driver pins at either end are normal driver pins. The 5 center pins are mushroom pins, in their properly installed orientation to the key pins.



If the wider end was facing the key pins, it would give the exaggerated counter-rotation we have been discussing. This way, the pin moves up fairly easily, then feels like it hit a wall as the flat part gets to the sheer line. It is more difficult to set these pins without dropping other pins. An inexperienced picker would feel that solid stop and think the pin was already set.

Gordon

[Richie Rich]

Thanks Gordan,

I'm aware of mushroom pins. My thoughts initially were that these pins would not give any false set indicators, but just be a real pain to set, because tension would have to be varied all the time and be more precise. The first one would be alright, but as soon as you go for the second, the tension has to be reduced enough to let it in, but not so much to drop the previous set pins. Essentially, as the pin rises, you have to reduce tension - so maybe it is easy to release too much and miss the point of setting - which is where you have to turn the tension back on!

If you then added in driver cone pins of different angles, the amount and speed you have to counter-rotate could vary with each pin. If the first pin was then offset slightly so it became the binding pin and then the second pin was a larger diameter (drive pin, not key pin), you then have a very tight window of setting the second pin and not dropping the 1st. With a variety of cones angles throughout the lock, I thought it would take a very very delicate tension hand to spp. - perhaps very hard to rake, since tension needs to be varied with each pin

But maybe it just makes it easier and the cone acts as a guide! If you can rotate the keyway by lifting a pin, then it would not work. If the tension has to be released in order for the pin to be able to be lifted, then that is what I thought would cause issues and turn the focus onto perfect tension - more so than with standard pins

Maybe I'll get a mushroom pin, cut off the top and bottom, spin it around and see what happens!

[GWiens2001]

Experimenting is the best way! Give it a shot, try a few ideas out, and let us know what you learn. We are all learning here!

Gordon

[fgarci03]

If the first pin was then offset slightly so it became the binding pin and then the second pin was a larger diameter (drive pin, not key pin), you then have a very tight window of setting the second pin and not dropping the 1st.

Well, not really. A binding pin isn't necessarilly the first one to bind. The binding pin is the one that can be set before the others. For example with all spools and one regular pin. The regular driver pin is the one that feels binding, but is not necessarily the binding pin. If you set it you go to a false set, but when you set the next spool it may (or may not, depending on the binding order) drop, removing the false set again. But the spool will be set. So you don't actually have a window of oportunity there. You either set the right one, or it'll drop when you set the next. Which kinda adds difficulty to the mix

With a variety of cones angles throughout the lock, I thought it would take a very very delicate tension hand to spp. - perhaps very hard to rake, since tension needs to be varied with each pin

That, I believe, is true. At least on raking. It should be like raking a lock with different spring pressure on every chamber. But, as you and Gordon said, best way is to experiment!

If you can rotate the keyway by lifting a pin, then it would not work. If the tension has to be released in order for the pin to be able to be lifted, then that is what I thought would cause issues and turn the focus onto perfect tension - more so than with standard pins

Yes, that is the big issue. You can rotate the keyway JUST by lifting a pin. You don't need to "try" and reduce the tension.
Of course you need to reduce it, or you'll damage your tools, but as soon as you start lifting the pin, the keyway just rotates back a bit, and you go with it. But always maintain a constant and small level of tension, so when the pin sets, it immediatly rotates again.

I don't know if I was clear on this. Check this:


At about 30secs the lock is in a false set, with just one pin left to go. Check how the plug rotates back while I maintain tension lifting the pin. As soon as the pin set, it rotates again and the lock is opened.


Anyway, I think these pins wouldn't add much difficulty to the mix. But with varied angles they would mask the real binding pin and make me go back and forth seting and hearing pins drop untill it pops.
Let us know what you find

[Richie Rich]

Thank you all for your thoughts!

When I get a chance (probably after few months practice!) I'll have a play and let you know!