Impressioning Qs

[Trip Doctor]

A few days ago I read over the sticky impressioning guide here again (at least that's the one I think I read...). Somewhere in the thread, there was advice to file each mark (from each pin) individualy to make the process easier.

Now, let's say you have perfect vision, and you can see any little mark.
Would you not end up filing the whole key down to it's deepest cuts, until the pins would no longer touch the key (as the pins will push on the key untill they no longer touch them)?

Let's say you don't have perfect vision though. Let's say you can only see a mark made under a certain amount of pressure. Could you not end up filing the whole key down a step or two deep, or not far enough? By this I mean, if the working key is a 65734, you would file to 54623, or 76845.

I'll throw this next question in here as well, since it's towards impressioning as well.

I have seen triangular files and teardrop shaped files reccommended here for filing down a blank. Wouldn't a trapezoidal file be ideal for filing down key blanks, as it would give a flat area (usually refered to as the 'valley' I believe) for the pin to rest on, and the little triangular hills for the pins to glide over to the next valley?


Thanks,
TD.

[Eyes_Only]

Once you have a part of the key filed to the proper position with the pin stack at the shearline it'll stop making marks on the key.

I'm not quite sure what you meant by your second question but in cases where you think you may not be getting marks where you should be then just stop filing there and move onto the next mark you can see on another part of the key. Sooner or later that first mark you couldn't see before might start showing up again.

Theres a real art behind impressioning that'll take a lot of time and practice to develop so patients and lots of key blanks are necessary.

[Wrenchman]

Yes, you will file down the key the the deepest cut, with perfect vision, but after you have done that about *25 times(and I talk from experience), you will start to cut the real marks only!

*And I did´nt count all the keys you break by the shoulder before you even get halvways!

Btw, what you call perfect vision is really lack of vision!

I have never heard about a trapezoidal file, but I think you don´t want to use that, but rather a pippin file(teardrop shaped file)!



Wrenchman

[Trip Doctor]

Mmm, well... what stops a pin stack from making marks once it's at the shear line? The spring tension is still on, so it will still press on the key, just not as hard as it did before the key was filed.

Yea, I guess a teardrop is just a curvy trapezoid, lol. Just when looking at cut keys the valleys are flat, which won't be much with a teardrop... or do teardrop files have kind of a flat bottom?

[Rodfather23]

Now I haven't successfully impressioned a key yet but, the pins only mark when they bind....if the pin is at the shear line, it will no longer bind.

[Rodfather23]

not to high jack this thread or anything, but does anyone have a or maybe a link to a good video that shows someone impressioning a key and showing the marks the pins left at the same time? I've been searching for a few days and haven't found one yet. I would guess this would also help tripdoctor as well. A picture would also be nice of where a pin marked on a key.



Rodfather

[freakparade3]

A picture would also be nice of where a pin marked on a key.



Rodfather

I don't think it would help. The marks don't always show up looking the same from lock to lock. My best advice to anyone trying to learn impressioning is to start with one pin. When you get a smooth working key move to 2 pins, and keep going. It's just like DB's picking exercise but instead of picking you are impressioning. It will help you learn to "read" the marks on the blank.

[Rodfather23]

Rodfather[/quote]

I don't think it would help. The marks don't always show up looking the same from lock to lock. My best advice to anyone trying to learn impressioning is to start with one pin. When you get a smooth working key move to 2 pins, and keep going. It's just like DB's picking exercise but instead of picking you are impressioning. It will help you learn to "read" the marks on the blank.[/quote]



Thats an awesome idea.....I've been just toying around with it (still with my chain saw file) and I can't seem to see the marks.... I'm going to go do that now.

Thanks

[freakparade3]

I forgot to add in my first post, after you get a working key with one pin and add a second, you should start with a new key blank. What method are you using to see the marks? Are you knife edging the blank? Recently I tried using a dremel to knife edge the blank really thin with good results. Also never give an impressioned key to a customer. It may be weak from the impressioning process. After you have a working key code cut a new one.

[Rodfather23]

I've only tried to impression twice so far........I haven't knifed edged yet. I've done the blue marker and tried some 800 grit sand paper. I still can see them. I'm going to order some blanks soon and a good file. I took out all of the pins except one just now to try what you said, but I just realized I'm out of blanks. and I think I have completely hijacked this thread sorry trip

[Rodfather23]

^^^ that can was obviously suppose to be can't^^

[Trip Doctor]

No problem Rodfather, lol, at least it's about impressioning so it's all good.

the pins only mark when they bind....if the pin is at the shear line, it will no longer bind.

What exactly prevents the other pins from making marks on the blank? If anything, wouldn't a binding pin make LESS of a mark?

I understood impressioning to be based on the fact that all the driver pins are the same; therefore the longer key pins will cause that pin stack to press down harder on the blank, expecting a deeper cut (which is what's needed to set those pins), while the shorter key pins will not press as hard on the blank, expecting more shallow cuts (which is what's needed to set those pins).

[aussielocky]

Consider the impressioning process.

1 - Apply rotational tension to the plug via the key.

2 - Move the key, pull system / bump & grind (whatever system)

Pins that are not currently at the shear line will mark the blank. Now when the key has been filed down to the correct height for any given pin that pin will not lock up when the tension is applied, hence a very light or no mark.

So being able to tell the difference between the different type of marks is critical. Personally I allways go for the strongest mark 1st and ignore all the others until there marks become more distinct.

[Trip Doctor]

Ahh, understood Thanks aussielocky.

So ideally, would you have to apply heavy tension so that ALL the pins bind (or like 2 from one side 3 from the other)?

[aussielocky]

Ahh, understood Thanks aussielocky.

So ideally, would you have to apply heavy tension so that ALL the pins bind (or like 2 from one side 3 from the other)?

Where it looks like all the pins are binding something is wrong, usually your blank is about to snap

Seriously though, be wary of locks that indicate too well, as if you do progress too deeply with a cut and miss the sheerline that pin will continue to make until you have filed right to the bottom of the key .