Shop considers investing in 5-axis machining
If your shop makes parts that demand multiple setups, parts that have challenging geometry or parts with difficult GD&T requirements, 5-axis machining could provide significant…
When I started my career in machining, it was common to find machine shops that did not have CNC machines. My family’s shop, for example, did not get its first machining center until 1995. We paid what felt like a king’s ransom for a small, 3-axis vertical machining center before adding another machining center and, eventually, 2-axis turning centers.
Image courtesy of Hurco.
What really made a difference was the addition of a rotary table as the 4th axis. Being able to reach multiple sides of a part in a single setup gave us a competitive edge. From that point onward, every machining center we purchased had a 4th axis.
Four-axis machining centers became the norm at our shop, but over time it became apparent that 5-axis machining was the holy grail. Five-axis machining was an elusive goal for our shop—the investment required, coupled with the commoditized nature of the parts, seemingly did not justify the expense.
On many occasions, we discussed the potential ramifications of purchasing a 5-axis machine. Ultimately, we decided against it.
Considerations
We studied how 5-axis machining related to the geometry of the parts we manufactured and how we would operate a 5-axis machine. Our parts were simple compared with those produced by other manufacturers. Aerospace parts like jet engine blades and medical parts such as replacement joints are complex and often require simultaneous machine tool motion in all five axes. (Machining in more than one axis is called interpolation.)
A simpler form of 5-axis machining is referred to as 5-sided, or 3+2, machining. With this approach, a part is manipulated so five sides of a part are accessible, but interpolation in all five axes is not necessary to complete the geometry. Consider a cube that has a feature machined on the top and each of the four sides; the machine turns the part so each side is positioned for the tool to perform its work.
Next, we considered the dimensional tolerances of our parts. Five-axis machining makes it easy to hold close dimensional tolerances on multiple faces. Traditional machining methodology requires multiple workholding devices to access all faces. Having a setup with multiple coordinate systems, multiple workholding devices and numerous setups makes troubleshooting dimensional errors difficult.
Five-axis machining makes it easy to hold close dimensional tolerances on multiple faces. Image courtesy of Heller Machine Tools.
Review the print ads from this magazine to continue
This quick advertiser review unlocks the rest of the article and keeps the full-screen reader focused on the ads instead of the page chrome.
