Do I Need a Five-Axis CNC Router?

A discussion of the rare situations that make 5-axis capabilities a necessity. October 28, 2008

We are looking at buying our first CNC and are looking at Northwood pretty well, but I am unsure if we need to drop the dollars for a five axis machine. I believe I understand the capabilities of both but am unsure if I will need the two rotary axis. Anyone here bought a five axis only to learn they didn't really use it much? Or bought a three and wished for a five? We are a custom shop that really only supplies for the houses we build. The work we do, however, is quite diverse, making it hard to decide.

Forum Responses
(CNC Forum)
From contributor R:
Unless you plan on doing a lot of carving and sculpting you don't need a 5 axis machine. The software cost and complexity alone would steer me away from a 5 axis. If you mostly build cabinets and millwork, what would a 5 axis do for you? Mold making and sculptures need 5 axis.

From contributor M:
Contributor R's comments are dead on. In addition, strictly from a manufacturing perspective, most customers I encounter with 5 axis capabilities are furniture manufacturers. They are making complex furniture components which they want to make in a "done in one" (discreet operation) philosophy. I also observe that often first time CNC buyers (3 axis router or point-to point with routing capabilities) typically meet their initial demand in less than one shift, often less than half a shift. Unless you do a substantial (more than 30-40%?) amount of carving, furniture making, architectural ornamentation, I would recommend beginning with a 3 axis. Your current business structure and flow or your proposed future business structure and flow will best determine what type of 3 axis machine you should pursue (flat table, pod and rail, router vs. point to point, etc.).

From contributor T:
Most people that buy a 5-axis machine have the need to machine on the side of a part or in a non standard plane, or the ability to trim around the edges of a part like a curved chair back, or a carbon fiber car fender, or drilling holes on odd angles. 5-axis machining is not about carving, however if that is what you want to do with it you can. What kind of parts do you want to cut? Show us a part you think you need a 5-axis machine for. There is a learning curve to 5-axis programming. If you do buy a 5-axis machine be sure and discuss tool tip programming capability with the salesperson. There are a lot of companies out there that can't do TTP efficiently.

From contributor C:
One other thing to keep in mind, if you are concerned about limiting yourself with a 3 axis, is most likely you can find a combination of aggregate head and/or rotary positioner (4th axis) that can accomplish what you need. This is easier and cheaper to program than a full on 5 axis system. You may want to discuss this with your sales guy to make sure you get a spindle capable of running aggregate heads, and if the software will run a 4th, most CAD software will handle both pretty easily.

From contributor G:
Be careful with this, as the machine in question could be a 2 table machine which has 4 axes, and support to rotate an aggregate the 5th axis. Be certain to check if this is the configuration, or is it really an articulating head 5 axis machine.

From contributor O:
It depends on what you're doing. For example, most cabinet shops are using 3 axis machines, while some door companies are using five. What is your application?