Providing CNC machining of space components requires the use of precision machine tools. As the space market expands, there is a continued demand for tighter tolerances, improved surface finishes, on more complex shapes. In the past, the CNC equipment used to produce these parts were two-axis (lathes) and three-axis (milling). Many of the more complex shapes were produced using a combination of these machines which required multiple setups. With advances in control, servo, and tooling technology, we can now accomplish 4- and 5-axis simultaneous machining on the same piece of equipment which has significant advantages when creating complex machine shapes with tight tolerance.
Early versions of CNC machines moved in two linear axes (X and Z) – lathes and three linear axes (X, Y, and Z) – machining center. The term “5-axis” refers to the number of directions that the machine can move while cutting simultaneously. Utilizing 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.The ability to not have to move the workpiece out of the initial chucking or workholding device has a distinct advantages when machining a part.
Tool Life Improvement
Improved tool life and cycle time is a result of being able to position the cutting tool is an optimum cutting position for maintaining consistent surface footage and chip load conditions.
The Ability to Machine Complex Shapes
The major (and most well-known) advantage of five-axis machining is the ability to generate complex shapes. The ability to move the cutting tool at complex machining angles and arcs, enable the ideal conditions for chip relief, without having to use special work holding or fixturing.
Reducing the Number of Machine Setups
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.
Relational Accuracy
Tolerance stack up creates imprecision. It is the result of having to move the part out of the initial holding or fixture position and re-chucking.Once a part comes out of the first chucking the precise alignment is lost.In many instances with 5-axis machines you are able to hold the workpiece in the initial position, maintaing the same “zero” or “home” location, and feature-to-feature accuracy is achieved.
3+2 Axis Machining
Some 5-axis parts are machined in a simultaneous 5-axis movement. Some 5-axis parts can be machined utilizing 3+2 axis movement. In 3+2 machining, the fourth and fifth axes are used to locate the workpiece (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. The same tool paths could have been achieved in a three-axis machine, but only after loading and unloading between multiple setups, fixtures, or machines. The five-axis machine increases uptime, decreases human error, and eliminates the need for special fixtures.
Improved Surface Finishes
Using the rotating fourth and fifth axes, the part can be positioned to bring it closer to the cutting tool. The shortening of the cutting tools cutting tool makes it less susceptible to vibration, which increases tool life and improves surface finish.
As technology advances, so does the market’s expectations for higher quality products at competitive pricing. To meet this challenge, Intrex has made significant investments in 3-4-5 axis equipment, as well as in 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. Contact Intrex today.
