Hi Guys,
I'm posting this information in case it is helpful to anyone else AND, since it requires the change key window to be open, it shouldn't constitute information that tells people how to "crack" an S&G 8077 padlock. If this is in contravention of site rules, I'm sure a moderator will delete/move it.
So, I purchased an 8077 on eBay a while back. I immediately read the instructions on how to change the combination from the default "25-0" and did so, without trouble. Unfortunately, I hadn't really read the instructions as well as I thought so completely screwed up the combination. Of course, all I needed was the "combination recovery key" to sort this out, but where to find such a beast?
Well, long story short, here are a few observations that will help the hobbyist get their 8077 and similar locks open. (assuming that the back plate is off and the key change window are open)
First, the change key tells you all you need to know about dimensions for the recovery keys. The key element is a square key that is approximately 2.7mm square or a little over .1" square. The full depth of the key for the 8077 is ~.85" to the top of the tab (where the key has been turned round, to allow for rotation in the square key change hole.)
Now, you need two keys to accomplish the recovery. The first is a largely round key with a small, square end to individually lock/unlock the wheels and round the rest of the way, to allow for turning of the key in the square key hole in the back plate of the lock.The way I made this was to take a piece of .125" square brass bar stock and mill it down to .1" square for ~2". I popped it into the lathe and rounded the bulk of this length as round, starting .15" from the square end. This is the key to individually unlock the wheels. I bent a suitable right angled handle for it after cutting it off.
The other key is simply a piece of brass stock, milled again to .1" square, that is .85" long. Beyond that length, the key needs a rounded section to allow it to turn easily in the die-cast key way. It likewise got a right angled bend to make a handle for it.
Now, here is where I screwed up multiple times. first, the wheel locks can turn 360* and so presumably act as cam locks. They seem to lock/unlock every 90*. I say this because I initially got the wheel cams oriented so that the change key would work, but I seemed only able to get the change key to re-lock everything after combination reset while the tab was trapped under the back plate. The change key only has a 90* turn range, and is blocked by the key shutter.
Anyway, once I got the wheels lined up using the recovery tool information sheet, I inserted the first key (largely round with a small, square end) in until I engaged the square wheel lock mechanism of the third wheel. Twisting 90* allowed me to leave the tool in place while continuing to turn the dial in a counterclockwise fashion, moving the next wheel into position. Same process for each of the next two wheels. Success is when you can see the tool the full .8" into the lock body AND the dial turns easily. As the instructions go, for any wheel that doesn't turn more than a few degrees, you're probably in the gate NOT the wheel lock. The gate and wheel lock are 180* apart. (see the patent)
https://docs.google.com/viewer?url=pate ... 533253.pdfhttp://www.mbausa.com/Files/8077_Combo_Recovery.pdfIn fact, the absolute confirmation that you're on the right road is to take out the reset tool (the first one you made with a small square end) and without turning the dial, insert the change tool. It should (read MUST) fully enter the body of the lock, passing through all three wheels. If the tab doesn't completely enter the lock, you haven't lined up the final wheel properly. While the change key is in place, you will still be able to turn the dial freely since all wheels are unlocked. Next, try to turn the change key 90* clockwise. The wheels will now ALL BE LOCKED, but of course the tab prevents you from removing the change key in this position so you need to take this key out and insert your second tool.
The second tool simply allows you to lock the wheels AND remove the tool you need to lock them. Insert it and twist 90* and remove.
Once the wheel pack is properly locked, insert the change key (should go in all the way AND twist clockwise into the change position. The dial will again freely turn. Set the combination CAREFULLY using the change index. To recheck that you have indeed set the combination properly, dial it in USING THE CHANGE INDEX, and once entered, reinsert the change key to make sure that the wheels are completely aligned. Do this a few times to ensure you actually have correctly changed the combination. Once certain, twist the change key shutter to the closed position. It actually won't let you if you haven't lined up the wheels (ie entered the correct combination) properly. Remember, you may have set the combination, but it may not be set to what you THINK it is.... that's why you try it a few times.
Ok, you've now hopefully sorted out this messy problem that has taken me the better part of a day to solve. That said, an alternative way to do this is to get a couple of change keys (readily available on ebay or from various sources) and modify them to create the necessary keys. It's tedious but not difficult. It can be done with a file, if you don't have a mill/lathe handy.
I certainly understand this lock much better than I did when I started, which was the goal for me. Someone mentioned the "offset" in one of the posts. Without going into too much detail (not sure how 'secret' this information should be.... but an experienced member was cautious about revealing too much detail so I will do likewise), two observations are important. The first is that the key change window and the change index are at positions 1 and 7 on the clock. We know that the gate and the wheel change hole are 180* from each other. If you have really good eyes, you should be able to deduce the combination from this information BUT, only if you can actually see the wheels!
Anyway, I hope that this is helpful to someone.
Good luck everyone!
Nitrous
