Machine operators use keypads and computers to run tooling programs and measure parts with digital gages and coordinate measuring machines. By definition, CAD/CAM work is accomplished digitally. Machine tool controls have digital displays. On most tool presetters—even simple ones without a vision system—the readout is digital. Bore gages are digital, whether it’s an air gage or a three-point-contact gage. There are still a few old-timers who trot out ID micrometers once in awhile, but most measurement devices are digital for speed and accuracy.
Digital has become the common language in metalworking and machining. The primary advantage of digital is its precision. There’s nothing subjective about a numerical reading. And this advantage has made its way to the boring head, where it is has been established technology for 10 years but is still far from being universally used.
As such, digital boring heads bridge the technology gap between digital measuring technology and existing tooling systems by adding a digital readout (DRO) to clearly show incremental diameter changes. So when an operator measures a bore and finds it undersized by 0.0004 " on the DRO of his measurement device, he simply has to zero the boring headreadout and adjust the diameter until the digital display reads “+0.0004 ".”
For the tightest-tolerance operations, one comparative drawback with analog systems is the frequency of human error—especially when the dial divisions are 0.0005 " on diameter. In addition, vernier markings complicate the adjustment procedure when it is necessary to split the divisions even finer. At that point, operators aren’t just moving from one division to another; they are forced to keep track of two different sets of markings to make fine adjustments, which can be confusing.
Of course, an operator could misread the number of zeros on a digital boring head, turning 0.0005 " into 0.005 ". But that error happens less frequently than an error caused when adjusting to a dial marking on a head that doesn’t have a DRO.