I took a break from safe locks to try and open an old combination lock that I've had lying around for a while. It's got no markings and the sticker on the back is worn off.
I've had this thing since the 80's and forgot the combination long ago and thought I'd try to manipulate it open. That actually went fairly quick...there was one HUGE indication at 33 which was easy to deduce was on the drive cam. I parked w1 and ran w2 around and found another indication at 12 or so. Since I was only moving w2 and the drive cam, I went with the assumption that it was on w2 and not just a nub on the cam. I should say that this lock is very sticky and drags a fair amount in spots when turning the dial.
Anyhow, started looking for the first number in 2.5 increments and found it at 27.5. The combination was:
I've been goofing around with rotational conversion and try to open locks with both L-R-L and R-L-R dialing sequences just to play around and practice, so I figured out the rotational differences for the wheels and found that w2 picked up about 1 increment early, and w1 about 7 increments early.
With these fixed drive pin locks, since they pick up early, the rotational conversion is the opposite of a group 2 lock, so converting from right rotation to left rotation will give you a lower number, and from left to right will give you a higher number.
The reality is that with combination locks like these, including Master locks, the gates are pretty wide. I find most to be about three increments of the dial, so adding one to the second number isn't always required unless you are right at the edge of the gate. So I dialed in 12 as the second number and the lock opened.
So I did some checking and found that the second gate had shifted lower by a number, not higher as I expected.
I confirmed that I wasn't a total idiot (in this case anyhow) by checking a couple of Master locks and a Sentry safe (direct entry with fixed drive pins) to be sure they acted the way I expected. They did. I checked the padlock again to be sure I wasn't screwing something up. Nope. The second gate really did shift the wrong direction!
Does anybody have any ideas? Is it something simple that I just haven't learned yet? Or is this lock an enigma?