I will add that the more I look at this stuff, the more respect I have for the trade of “Locksmith”. It is so wide-ranging and complex. It is so much more than the “colouring in” qualifications, even of so many university degrees now.
Using a Vernier scale to correctly determine the contact points can make the job for we beginners so much easier. It gives accurate readings to a tenth of a division – exactly what is needed to crack the code.
Here, I will attempt to (a) show how to read a Vernier scale, and (b) where to get it.
The Vernier scale used to manipulate the lock is typically a 10-division scale that spans 1-9 on the rotating dial, and is stuck to the fixed part of the dial.
If the dial is rotated to say, here (below): Visually, you can have a crack and guess it being about 10.5. But looking at which Vernier scale number-lines align best with any line on the rotary dial, it is clearly 5. Thus is it 10.5. Piece of cake!
The thing is, people can easily align two lines. It is far more difficult to guess at the fraction after the 15 shown below. So, looking along the Vernier scale, we see that the two lines that best align are at 7. Therefore it is 15.7
And below, you might guess at 15.1. Or 15.2. Or 15.3. But looking at the Vernier scale, the best alignment is at 2. Therefore the value is 15.2.
So easy!
There is a good 4-minute video showing how to read the Vernier scale on a safe here:
https://www.youtube.com/watch?v=rMeQ1tG_o0E
Credit to Alexander Mundy who put that short video together. In fact, one of the pictures that I have at the top of this post is a grab from his video.
Perhaps more importantly, to the VERNIER SCALE:
The Vernier scale can be obtained here in web archive:
https://web.archive.org/web/20221112214 ... rnier.html
There are 14 variables you can play with. Here are some:
• Wheel diameter,
• number of Vernier scales desired,
• rotation of wheel,
• number of divisions on wheel (not necessarily 100),
• show or not show the wheel,
• size of Vernier numbers,
• size of Vernier marks,
• You can even measure the value in eighths of a division instead of tenths of a division. Like 4 3/8. Although why you would want to do that, I don’t know.
This, from that site:
Yep! 13.8
Best to have a play on the site. Once you have the details sorted, you can download it to your computer as an .svg file. Double click on the downloaded file to open it. Scalable Vector Graphics (SVG) files open in a web browser page and can be printed from there. Alternatively, you can “print” it as a pdf, and save it that way. Alexander Mundy printed them onto self adhesive contact paper.
I prefer the middle graph above with no dial, 75mm dia (for my locks), larger font size, and thicker lines and six or eight vernier scales around the perimeter.
The only care required is cutting the Vernier scale to fit your lock. It must MUST span your dial 1-9, and trimming it for that is not real easy.
I wish it was out of “archive” and on someone’s active site. But that is above my pay grade. Full credit to the person who put it together. Brilliant work!
Of course, the experts move past this and generally don’t need it. But it does help for accuracy, especially if you are graphing it. And, I don’t know about you, but I need all the help I can get!
Cheers,
Ralph
