Rotational conversion enigma

[Mikeh727]

Hey guys,

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:

R27-L12-R33

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.

Or at least, it always has before.

I dialed in L20-R13-L33 (the last number stays the same since it's on the drive cam and connected to the dial.)

Pulled up on the shackle and....

Nothing.

Redial...

Nothing.

Check the wheel pickups again. 1 and 7.

Redial.

Nothing.

DAMN!

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.

But still...

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!

Soooo....

Does anybody have any ideas? Is it something simple that I just haven't learned yet? Or is this lock an enigma?

Cheers,

Mike

[GWiens2001]

Mike,

Just tried it out on two master padlocks. Did not try for rotational conversion, but simply made the adjustment to the first number as you did, leaving the second and third numbers unchanged. The first one opened up just fine. The second was a no-go. Tried raising and lowering the first and second numbers separately one and two numbers, still no go. Don't have time now, or I'd check the pick-up points. But it is cool.

Gordon

[Mikeh727]

Hey Gordon,

Thanks for trying that out! The Master locks I have are all the basic school locker variety, and all were purchased in the last year in support of my lock addiction.

Master makes other combination locks as well that I haven't played with yet, and they could be different. But I would think any of them could be opened dialing L-R-L if you figure out the rotational conversion. If you do get a chance to play with your locks a bit, I'd be interested in what you find.

Thanks!

-Mike

[GWiens2001]

I'll check it out. Will say that the one it worked with is newer, while the other is 25+ years old.

Gordon

[Oldfast]

Hey Mike. I too have been enjoying combination padlocks of all sorts. Good ol' portable fun

I grabbed a few of my Master 1500's. The pick-up differences for these were 3 & 7.
I also grabbed a few of the Master Spheros. Pick-up differences for those were 2 & 7.
ALL of them required the 2nd digit to be adjusted, otherwise they didn't open with LRL.

Not really sure what to say on the scenario you have there. Might just be that lock.
You probably already have, but did you dial the working combo while progressively
working w2 from one side of the gate to the other? Figure out what true center is.
What you found was obviously within the gate, but maybe it wasn't exact center?

And yeah, just to confirm...... your thoughts on fixed drive pins and how they convert ARE all correct.
Also, you can say left/right, plus/minus, lower/higher increments, etc.... whatever makes sense to you.
But MY little pea-brain doesn't always handle that too well, lol. So I like to just say:

w/ combination padlocks: simply stop short of the original # by the appropriate amount.
w/ safe combination locks: you dial beyond the original # by the appropriate amount.

For me, it's easier to see & keep track of it this way.

[Mikeh727]

Hey Mike. I too have been enjoying combination padlocks of all sorts. Good ol' portable fun

Hi Mike,

Actually it was your video on Master combination locks that really got me going with combination locks. I found it a little over a year ago when I had been fiddling around opening them the 'long' way...find the third number and possible first and second numbers and brute force the possible combinations. When I stumbled across your video, I went out and bought a whole bunch of locks to practice with, and still carry some with me when I travel. Like you said, good portable fun! And I love the technique!

ALL of them required the 2nd digit to be adjusted, otherwise they didn't open with LRL.

Interesting...I didn't check all of mine but the couple I tried would open without adjusting the second number. Although the pick-up difference was only 1 to 1.5 on those locks for the second wheel so that might be the difference.

You probably already have, but did you dial the working combo while progressively
working w2 from one side of the gate to the other? Figure out what true center is.
What you found was obviously within the gate, but maybe it wasn't exact center?

Yep, did that with both the R-L-R combo and the L-R-L combo, and the gate truly did shift the wrong direction by nearly a full increment. It's tough to tell exactly how much because of the amount of slop in the dial, but the shift was there.

I think it's probably just something with this lock. It's a cheap no name lock but fun to play with since it's different from the Master locks that I'm used to.

w/ combination padlocks: simply stop short of the original # by the appropriate amount.
w/ safe combination locks: you dial beyond the original # by the appropriate amount.

For me, it's easier to see & keep track of it this way.

Hehe...my little brain has a problem keeping that straight as well...I had to actually write it down to be sure I posted it right! I like your simpler version!

Thanks for the info.

Cheers,

Mike

[Oldfast]

Something else I'm noticing as I run through more of my 1500's is that the pick-up differences can vary slightly.
Some of them are 3 & 7. Others are more like 2 & 6. Could be due to wear, or maybe a lack of quality control.

[GWiens2001]

Something else I'm noticing as I run through more of my 1500's is that the pick-up differences can vary slightly.
Some of them are 3 & 7. Others are more like 2 & 6. Could be due to wear, or maybe a lack of quality control.

Are you insinuating that Master has quality control issues??? Say it ain't so!

Gordon

[Mikeh727]

$5.00 worth of quality control in every lock!

-M

[keyloser]

Guys, this is wonderful.

I do not have Master Lock 1500/1502/1503/1530/1533 yet, but I have tried this with very similar ABUS 78/50 of mine.
The differences are: −6, +3, 0 (or "3 & 6" in your terminology, I guess).
(e.g. 10-20-30 R-L-R = 4-23-30 L-R-L)

I have never played with safes with mechanical combination lock, but I have read about them before having discovered safe-like combo padlocks, so I am already more accustomed to its rotational orientation - therefore I might be biased already.. but I really consider left-right-left rotation more natural, because both initial and most rotation(s) slide through the dial in ascending manner (which is what the natural number sequence does).

EDIT: .. well, provided that the dial ring is numbered clockwise, of course. I have seen some reverse dials.