|Recovering the Combination for the Sesamee Combination Padlock|
|Before testing your skills on the
Sesamee lock, please read and become familiar with the method for
recovering the combination for the Master 175 thumbwheel
Click here if you need to go to the Master thumbwheel lock instructions
According to a press release from the manufacturer, the Sesamee's design has evolved over the years since it was originally patented in 1926, but the basic design has remained unchanged. Also, the press release implies that the design has incorporated security improvements, so padlocks of earlier vintage may be easier to open.
We believe that we have tested padlocks of current design. However, according to a press release, the Sesamee is "virtually impossible to pick open by both vandals and professional thieves alike." We didn't have all that much trouble recovering the combination. Maybe they don't consider this procedure, using a feeler gauge instead of lockpicks, to be "picking open" the lock. Maybe we can get the lock open because we aren't vandals or professional thieves.
Bear in mind that it is possible that they changed the lock design and that statement is accurate for current production locks. However, if you have trouble with the method, don't just assume that the manufacturer has modified the design so that the method doesn't work on your padlock. Give the method a careful try before giving up.
Overview of the Procedure
1) Using an automotive feeler gauge, recover the first (left most or thousands) and third (tens) digit in the combination.
2) Either recover the second or fourth number, using another procedure that requires additional skill, or just try all possible pairs of digits for the second and fourth numbers. There are 100 pairs to try, but, on average, the lock should open in 50 tries or less.
Differences from the Master 175 Procedure
1) The feeler inserts deepest in the Master when the cam's flat surface is located. Just the opposite, the feeler inserts deepest on the Sesamee when the cam's flat surface is misoriented. This difference is because the Sesamee uses thin cams with a wide gap between the cam and the thumbwheel. The feeler doesn't hit the cam top surface when the cam is misoriented; it slides down next to the cam instead, accounting for the deeper insertion.
2) In the Master, all 4 numbers can be recovered with the feeler gauge. In the Sesamee, we only recover the first and third numbers. We recover one more number using another procedure, or both other two numbers by trial and error. This differnce is because the cams for the Sesamee's second and fourth numbers are more difficult to probe than the other cams. They are to the left and relatively far away from their thumbwheels..
3) The thumbwheels for the first and third numbers need to be set half way between numbers before probing. The Master lock cams can be probed with the thumbwheels set on numbers, although the last step is to move the thumbwheels half way between numbers to more precisely locate the correct numbers in the combinations.
Recovering the First and Third Digit
The first (left most) digit and the third digit may be recovered using a modified 0.0015 inch feeler from the automotive feeler gauge. The feeler has its end cut square with scissors and a line drawn with a felt tip pen about 1/4 inch from the end. Curl the feeler so that, when the feeler is placed in a flat surface (such as a table) with the line on top, the feeler curves up a little at the end.
Set the second and fourth thumbwheels on digits. Turn the first digit thumbwheel half way between two digits (thumbwheel is on a groove between numbers and not on a number.) Insert the feeler to the right of the thumbwheel, with the curvature so the feeler curves away from the thumbwheel, inside the lock. When you insert the feeler, you will need to work the feeler over a ridge on the thumbwheel. The ridge stops the feeler as it is just barely into the lock. Once past the ridge, insert the feeler gently deeper, and feel for stopping against something. Remove the feeler, move the thumbwheel to the next groove half way between two digits, and reinsert the feeler. Try all 10 positions, or stop if the feeler seems to hit something, the flat surface on a cam, and stops before going too deep. Use the line drawn on the feeler to help measure insertion depth.
When using this procedure, be gentle. Note that the feeler will insert deeper if you push harder, even if you hit the flat surface of a cam. You are trying to locate the flat surface of a cam.
Repeat the procedure for the third digit. For now, leave the thumbwheels where they are, but note that, as a later step, the first and third thumbwheels will need to be moved a up quarter turn (two and a half digits) to get to the correct digits in the combination.
Before going on, it is a good idea to recheck your work. The next step is eithor to try 100 combinations, which is boring and will take a few minutes, or to recover the second or fourth digit. You need to have the first digit correct to recover the second digit, and third digit correct to recover the fourth. If you have the wrong first or third digit, the lock won't open, and you may become discouraged.
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