Why 5-Axis Machining for Defense Components?
CNC machine tools are used for machining—metal removal—in the defense markets. CNC machines are well-suited to meet the demands of defense markets that require tighter tolerances and better finishes. Much of the CNC equipment used to produce these parts in the past were two-axis (lathes) and three-axis (milling). Many of the more complex shapes were produced using a combination of these machines along with multiple setups. Thanks to advances in control, servo, and tooling technology, we can now accomplish 4- and 5-axis simultaneous machining. Having this 5-axis ability has significant advantages creating complex machine shapes.
Definition of 5-Axis Machining
Traditional CNC machines move in two linear axes (X and Z) for lathes and three linear axes (X, Y, and Z) for machining center. The term “5-axis” refers to the number of directions in which the cutting tool can move. On a 5-axis machine, the cutting tool moves across the X, Y, and Z linear axes, as well as rotates on the A and B axes to approach the workpiece from any direction.
The ability to precisely move the work piece without removing it has distinct advantages over conventional three-axis machining. There are benefits of five-axis CNC machining:
1. Complex Shapes
The major (and most well-known) advantage of five-axis machining is the ability to machine complex shapes. The ability to machine in a continuous 5-axis move creates machining angles and arcs for the cutting tool and for chip relief that were only previously possible with a multitude of special fixtures or additional setups.
2. Improved Tool Life
Improve tool life and speed up cycle time as a result of tilting the tool/table to maintain optimum cutting position and constant chip load.
3. Setup Reduction
Five-axis machines can machine nearly every visible surface, excluding the bottom or clamping area. This ability significantly reduces the need for multiple setups or special fixtures. In some instances, it reduces the number of setups to one.
4. Improved Accuracies
Imprecision happens every time you have to “rechuck” the part. This tolerance stack-up is one of the results and challenges of moving a part for re-fixture. By using the same “zero” or “home” location, feature-to-feature accuracy is improved.
5. 3+2 Axis Machining
Not all 5-axis parts require full 5-axis simultaneous machining. Some 5-axis parts are best machined with a 3+2 movement. In 3+2 machining, the fourth and fifth axes are used to locate the work piece (or cutting tool, depending on the type of machine) in a fixed position. In these scenarios, there is no need for all five axes to move simultaneously.
Five-axis machining increases uptime, decreases human error, and eliminates the need for special fixtures. For parts with features or holes on multiple faces or angles, 3+2 machining is the clear choice.
6. Achieving Surface Finishes
Using the rotating fourth and fifth axes, the part can be orientated to bring it closer to the cutting tool. If the part can get closer to the cutting tool, then the cutting tool can be shorter. A shorter cutting tool is less susceptible to vibration at higher cutting speeds, which directly impacts surface finish.
As technology improves, so do the markets’ expectations for higher quality products at competitive pricing. To meet this challenge, Intrex has made significant investments in multiple-axis equipment, as well as systems software to oversee and control our entire manufacturing process.
We would welcome an opportunity to speak to you about addressing your supply chain needs.