Fab Lab Skill Builder: 4-Jaw Chucks

A popular tech line request is  for more information about setting up a 4th axis.  Earlier, we showed how to true a 4th axis to the mill motion using shims and how to set up a 3 Jaw chuck.   In this new video, Mike  C. demonstrates  how to set up a 4-Jaw chuck on a 4th axis.  He also shows basic tail stock setup.


A 4 Jaw chuck with independent jaws like the one shown in this video takes some care (and a little patience) to setup properly, as you’ll see from this video.  That seems to be why most machinists will do whatever they can to use a 3 Jaw chuck if the part permits – for example, starting with round bar stock to begin with, or turning or milling down a round stub end on a square workpiece  so it can be gripped with a 3 Jaw chuck.

As a rule, it usually makes a lot of sense to program any 4th axis work as the first setup in a multi-setup program.  This is because its a lot easier to reference a part for a second operation setup if you only need to worry about alignment of 3 axes.

Of course, that’s not always possible, and that’s what makes a 4 Jaw chuck so useful:)

More Tormach Fab Lab Videos:

Andrew Grevstad

With over ten years of professional experience in advanced manufacturing systems, digital design tools, and applied software, Andy Grevstad has worked in product development and technical support for Tormach since 2008. Grevstad has received engineering degrees from Michigan Technological University and the University of Wisconsin-Madison. He is a regular contributor to Digital Machinist magazine and also blogs weekly about CNC milling and related topics on the Tormach blog, Milling Around.

Andrew Grevstad