Tormach Fab Lab: How to Set up a 4th Axis

Just got a 4th axis and not sure how to start?  First things first – make sure you know how to properly set it up and align it to your PCNC mill.  Check out our latest Fab Lab Skill builder video to learn how to do it right.


This video also is a great demonstration of error stackup and the importance of knowing exactly what you are measuring.  It’s just another example of why a dial indicator is one of the most important tools in the machine shop.

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

3 thoughts on “Tormach Fab Lab: How to Set up a 4th Axis

  • May 28, 2013 at 4:02 pm

    I have always found 3 jaw chucks have 5-10 thou or more of runout over a 5 inch span. Wouldn’t that throw all of the dial indicator readings if your test bar had even a small amount of runout?

  • Andrew Grevstad
    May 28, 2013 at 5:01 pm

    Correct. This is why you never want to rechuck something in a 3 jaw chuck. If runout matters in your set up, you should be using 4 jaw independent chuck or 5C collet closer. Using a ground setup bar like we show here will get you pretty close, but you shouldn’t expect zero runout with a 3 jaw scroll chuck – choose a different setup.

  • May 31, 2013 at 1:44 pm

    I always love the intro to your videos. Thanks for posting this. This is great.

Comments are closed.