Russwin IC, it’s a familiar term. To define the BUP, we need to state that the thick- ness of the master ring sleeve component of the cylinder assembly is equal to a BUP of 0. The master ring sleeve is either .142" or .163" thick, depending on the plug di- ameter. Therefore, the BUP 0 pin is either .142" for the .552" plug diameter or .163" for the .509" plug diameter. Since the OD of the cylinder is 1½", re- Figure 9. This is the front view of a typical master ring rim cylinder. gardless of plug diameter, the thickness of the ring sleeve must be the variable to accommodate the plug diameter in use on that cylinder. This represents the “build- up dimension.” The BUP used is based not only on the bitting class but also on the system employed (System 70 or Pre- System 70). There is a full complement of BUP sizes available in the Corbin Russ- win PK-1070 pin kit to accommodate any environment you are pinning in. Our example system has 10 sizes of BUP from -4 through +5 (the ‘+’ is not used when describing BUP longer than the 0; it’s only used here for illustration purposes). In order, these would be -4, -3, -2, -1, 0, +1, +2, +3, +4 and +5. These are the same pin sizes, meaning the number and not length of the pin, for .509" and .552" plug diameter. The only difference is the actual length of each of the pins in the array, including the 0 BUP — again, based upon bitting and the system class. As an example, a +3 BUP in .509" = .247", and the +3 BUP in .552" = .226". There are then master pins that (in our Figure 10. The rear view of the typical master ring rim cylinder is shown. Because master ring is customarily mas- ter keyed only at the ring shear line, master wafers are usually found above the BUP in any given chamber. If master pins are found below the BUP, perhaps 40 KEYNOTES MAY 2021 the cylinder was maison pinned at the plug shear line or simply not pinned ac- cording to master ring best practices. The new concept here is the BUP, and if you’re accustomed to LFIC or Corbin current example) would be sized 1, 2, 3, 4 and 5. BUPs and master wafers are not the same and therefore cannot be used interchangeably. Finally, there is the top pin. For pur- poses of master ring, the top pin will al- ways be .171". However, in the greater world of Corbin Russwin, the length of the top pin is also based on the class of bitting and the cylinder type being pinned. Mortise and rim cylinder front WWW.ALOA.ORG
