b'\x1b\x1a\x19 \x1f\x18\x1d\x17\x16Machinists CornerTHE CHUCK STOPS HEREBy Brandt Taylor Theothermethodistheoldconsuming more time and money.standby of machining soft jaws,Whats been needed is a work stop S etting a z datum to do chuckerwhich always work. But machiningthat is accurate, versatile, quick and work on a lathe is a frequentthem costs time and money. Softeasy to use, plus it shouldnt interfere task for many shops. This activity in- jaws are machined to fit a specificwith cutting tools. To fill the void, I volves using some sort of work stopclamping diameter and z dimen- developed Stop Jaws, hard jaws with to get repeatable parts and ensuresion. Its possible to accommodateremovable hard work stops.that they are clamped squarely ina few different part geometries withEach Stop Jaw has an array of slot the jaws. Lets look at chuck jawsone set of jaws, but shops end uppairs that accept work stops and that speed up this process. investing in a library of machinedallow different z settings. The work In the past, there have been twosoft jaws. As it grows, so does thestops have an offset design to fur-methods for setting a z datum. Oneinvestment. When the job changes,ther increase the number of z set-is to attach a work stop to a chuck.the jaws may have to be changed,tings. Thirteen different z positions An example is a tripod arrange-ment that works with hard jaws andabout the author attaches to a chuck face with mag-nets. Thats simple enough, but itBrandt Taylor is owner of Berlin, Massachusetts-based Taylor doesnt work on a four-jaw chuck,Engineering, a machine shop and manufacturer of lathe puts limits on part geometry andchuck jaws. He can be reached at 978-838-2979. For more restricts axial travel of cutting tools. information about the chuck jaws, visit www.stopjaws.com.Using a Stop Jaw, a boring bar travels through a bearing retainer part to machine its internal features.Steven Taylor18 MAY 2020MachinistCorner.indd 18 4/16/20 12:45 PM'