Whats wrong with this bump key?

[parapilot]

First attempt at a bump key, with the wrong files and not much care - well it does not work!! whats wrong with it? Its a working key filed down from a try-circle 265, which i can pick pin by pin (can't seem to rake it open)

I think i'v taken to much of the first grove so its not bumping pin 1 right. I did this as i thought to take a little of the end and start of the key, but i didnt think and took it of the first grove rather than just the stop.

Any comments would be good. Next attempt i will take more care and use a more sutiable file!

[Fah_Cue]

when u put the key in the lock, if you push it in dose it spring out a bit. I think you need to take off the little "lumps" at the top and bottom of the key

[illusion]

You notice how there are flat sections between the peaks on the original? Make sure the width of these valleys is preserved in your bump key. You have used a triangular file and because of the fact that there are no flat valleys, none of the cuts are effectively at the lowest depth.

Hmmm... You should also take a small ammount off of the shoulder and tip.

[Shrub]

Dont tkae anymore off the tip theres enough removed already but i cant tell if the shoulder has been altered or not,

[Fah_Cue]

yer thats what i thought u need to take some off sholder.. and the under sholder bit because it will just get in the way

[illusion]

Oh right, I didn't realise they'd taken some material off the tip.

[Shrub]

He may not have done but it just looks like he has to me, the little lip is gone and its quite flat at the end,

Try putting the key in the lock so its sat right then put some hot glue over the key bow and around the plug, let it set and remove the key, youve now got a key with a bouncy stopper on it, thats the only way i could ever get bumping to work myself.

[darrel.h]

It could be that all the bumps aren't cut properly. They could be too short or too tall.

[Isakill]

This is a pic of my best bumpkey:



It works perfectly usually 1 or 2 taps is all that's needed to open the lock. The method I use doesn't require the shoulder removal. I place the key in all the way in the lock and then pull it out so that the last pin isn't engaged with the key. Then tap it.

It's a yale and I used a small round file to cut the key. Originally it was a working key that had 1 cut at it's deepest depth, I just used the file to cut the rest of the key.

You notice how there are flat sections between the peaks on the original? Make sure the width of these valleys is preserved in your bump key. You have used a triangular file and because of the fact that there are no flat valleys, none of the cuts are effectively at the lowest depth.

I've noticed that as well and I have ruined a few keys this way, so I switched to the round one

I also have a schlage and kwickset keys that I have made in the same fashion. [/img]

[Isakill]

sorry should have resized it a little

[zeke79]

My just be me, but your spacing in relation to the shoulder looks to be way off.

[Isakill]

well I should have also mention that I did file the shoulder down a little...
if my camera didn't suck so bad you could see.

[zeke79]

Sorry, my post was directed at the original poster.

[parapilot]

Yes, i think it is the shoulder area i have messed up. The lock is old and not the best either, sometimes it sticks with the original key!

Thanks for the comments, i will have another crack with a better quality lock when i get one.

Regarding tension while bumping, do you use a light tension then hit the key? or a heavy tension. If it has spools i would think you could only apply a light tension, or to you apply tension immediately after you have bumped???

Cheers
Jamie.

[p1ckf1sh]

A short one to all those making a bump key from an existing, pre-cut key (not blank). I order to get the depth of the cuts and their positions worked out halfway properly I used the following procedure:

1. Clamp key in vice
2. Unpack Dremel, put on cutting wheel (the thinner the better, a diamond cut off wheel would be best, thinnest one around)
3. Run Dremel on low to med speed and let the wheel cut down into the "V" of the cuts, right in the middle and straight down all the way to the point where the deepest cut would terminate (or where you think it would. That will essentially give you something looking like an "Y"

With this cut as a guideline for depth it is easier to make a proper bumpkey and also easier to keep the spacing intact.

From there, use your set of files to work on, I suggest radiused cuts (=round file) to finish it off. Had the best results with those.

Without a Dremel, you cna probably use a junior hacksaw to do the cutting, if you have a steady hand.