monkeypick wrote:Thanks Barbarian, that was helpful, and to 10ringo10 as well for taking the time to respond.
I guess my confusion was over the fore and aft cuts. I am having trouble with how it makes any difference on a code key. For example, if I cut 2 angles in each code space, it has to be either L-R or C doesn't it. How do you account for the fore and aft part. Would I not just draw a particular angle on a blank (two per code space) and just cut it ?
I am probably wording this badly, but say it is aft left 10 degree cut, if I just draw a left 10 degree cut in that code space and cut it, will it not work? Sorry to be so thick about this but I have looked at the pics on this forum of code setting keys and I can't tell if there is something special about the cuts or if they have just been drawn out according to the chart Barbarian has provided and can be cut using my trusty Dremel.
The "Classic" Medeco locks had a chisel point. The center of the point rested directly below the center of the pin. They had L-R-C cuts.
The Medeco Bi-Axial locks are very different. They don't have L-R-C cuts the Bi-Axial have K-M-B-D-Q-S cuts. The chisel point is not on the center of the pin. It is offset to the front or rear, ( before or after center ). Look up a few posts and you can see a nice picture of the offset chisel pins. So for any Medeco Bi-Axial key, if you were to cut at the center line of the pin, you would not be correct. The cut must be .030 in front of or .030 after the pin center line.
For example if you were to cut a Bi-Axial key with all AFT cuts and lets say we made all the angles Center just so the angles were not an issue. That key would not open a lock that was pinned with Fore and Aft pins even though the angles were all Center. The reason it would not open is that the chisel points on the pins that were FORE would not seat in your AFT cuts to the required depth. They would be held slightly high. Tobias talks about this too. He gives a chart on page 123 of "Open in Thirty Seconds". The chart has about 30 entries. A FORE cut at depth 6 opens a AFT cut at depth 5. That one depth difference seems to be standard through the chart.
One of the things that might be confusing is that a normal Medeco key for a Bi-Axial has 6 cuts. When you look at the key you can tell the spacing is not the same on each cut. The code setting and bump keys are all 12 cut keys (double cut) and its difficult to see whats happening. As far as the angles go, with a narrow code setting key, if you cut just one angle there is not much metal left to act on the pin. If you tried to cut two angles in the same space, say a 10 degree cut left and a 10 degree cut right that would open any pin, I don't think there would be any metal left to move the pins.
Lets say as an exercise you wanted to make a bumpkey for a specific Medeco lock and you knew the pinning of this lock. In that case you could guess the angles with your dremel. You need 20 degrees left at a certain space and we know that anything from 10 degrees to 30 degrees will probably work. Also there is no point in making cuts you don't need for this lock, so there would only be six cuts. The spacing would all be obviously different. Even though the pin spacing is .170 the space between a FORE and an adjacent AFT pin would be .060 more than the .170- Also the spacing between a AFT and an adjacent FORE would be .060 less than the .170- If all your pins were FORE or all your pins were AFT then the spacing would be nice and even for the whole key. You could probably get the depths right and the bumpkey would work. The problem arises when you want to make the minimum number of keys possible that open all the locks out there without knowing pinning ahead of time.
There was enough info in the book "Open in Thirty Seconds" to make a chart of the cuts for the bumpkeys, even though the actual cuts were not given in the book. It is an excellent book and if you haven't read it, I suggest you grab a copy. I posted the method I used to figure out the cuts for the bumpkeys and I think the cuts are here too. If anyone needs them I can probably find them again.
If we could get clear pictures like this for all 4 keys it would be a great help.
Pictures are out there, I can take more if I can find my set of keys, I really don't think the pictures will be much help though. The depth and space info as well as the cut profiles are all available. If you think pictures would help, let me know and I'll see what I can find.