Five-Axis Programming and Controls

A fear or pain point of 5-axis machining is often concern over how difficult these machines are to program and control. Fortunately, commercial CAM systems and CNC software have evolved to make the application of 5-axis technology easier, safer, and more productive.

CNC programming has historically caused bottlenecks in five-axis machining because of the complexities of the surface geometry and the many tool vectors. However, as CAM vendors continue to add features, programming is becoming more adept at creating efficient toolpaths in less time. For example, some systems layer five-axis features on top of a more familiar three-axis programming environment. You begin by generating a three-axis program as normal, and then add in the five-axis moves, for example, where the tool is tilted away from adjacent surfaces and avoiding collisions.

Commercial CAM systems and CNC software have evolved to make the application of 5-axis technology easier, safer, and more productive

Auto-Tilt Features

Auto-tilt features in some CAM systems allow you automatically generate 5-axis moves, in this case tilting away from the sloping surface to avoid a toolholder collision. (Image: Siemens Digital Software)

CAM Systems and Simulations Software

CAM systems have also evolved to support cutting tools designed to make 5-axis machines more productive such as circle segment cutters and multi-flute endmills, which can dramatically reduce both roughing and finishing cycle times. You can program in the tool shape so that the system can automatically generate tool paths with larger stepovers while maintaining or improving the machining tolerance to the surface model. The result is less need for blending, matching and stitching.

And new systems have a variety of features aimed at specific applications such as using circle-segment milling tools; high-feed and high efficiency machining; cutting turbine blades, impellers and blisks; and more.

Simulation software is also an important component in five-axis machining because there is a higher risk of tool and toolholder collisions. Some CAM systems have this functionality built into the software and there are also several very good 3rd party solutions such as Vericut from CGTech and NCSIMUL from Hexagon where you can model the complete machining environment—machine, material, fixturing and tooling. Using software like this could save you a lot of money in the long run.

CAM programs specifically designed for 5-axis machining

Fusion 360, Powermill and Inventor HSM from Autodesk
Esprit from DP Technology
Edgecam and WorkNC from Hexagon
Mastercam from CNC Software

Look for CNCs with Five-Axis Machining Features

The leading machine builders have also added a variety control features that can aid setup, simplify programming, enhance quality and improve safety. These advancements include:

Collision avoidance software in a CNC can apply a digital model of the entire machining setup to head off crashes before they occur.

Collision Avoidance: Because of the dynamic nature of moving both the spindle and the workpiece in a five-axis environment, unintended tool, workpiece and fixture collisions are a real danger. Control resident features such as Makino’s Collision Safe Guard (CSG) or Okuma’s Collision Avoidance System (CAS) can monitor the part program for possible crashes in real time. You can even import a Vericut file into the CNC which then replicates the full simulation in the machine control and shuts down the machine before a crash occurs.

Tool Center Point Control: This function on CNCs controls the movement of each axis by automatically adding the tool length offset amount to the toolpath program. It also controls the feed rate of each axis so that the tool center point moves along the part at the specified feed rate. With this function tool rotational centers don’t have to be considered when programming the part.

Toolpath Smoothing: “Lookahead” technology has been around a while where the CNC scans ahead in an active part program and dynamically adjusts the feed rate for tight corners and curves to maintain a more accurate toolpath. Today’s best CNC’s take that capability to a whole new level allowing very accurate five-axis machining at much higher feed rates while generating very smooth cuts and blends. This capability can both dramatically reduce cycle times and improve surface finishes.

Automatic Workpiece Offsetting: Some controls include automatic probing routines and find the actual location and orientation of the workpiece or fixture, and set 3D workpiece offsets accordingly.

Nano Smoothing: This FANUC feature activates real-time spline interpolation to recreate the smooth curve originally defined by the CAD system from the line segments modeled by the CAM system, improving surface finish and processing speed.

Easy 5 Axis CNC Machining

This video briefly shows a 5-axis programming process using Autodesk’s Inventor HSM CAM software.

CNC Simulation with VERICUT

This video provides examples of VERICUT CNC simulation projects on Okuma machines.

FIVE-AXIS MACHINING