Overview

Many people think that simultaneous multiaxis is the true form of 5-axis machining, when in fact, it is not necessary for all the machine axes to move at the same time for the machine to be considered 5-axis. Even a simultaneous 2-axis, rotary cutting motion may be considered to be a multiaxis toolpath.

Simultaneous multiaxis machining is also known as Continuous 5-axis or True 5-axis machining.

The illustration in Figure 5-1 shows a 2-axis machine cutting a pattern onto a bowling ball. This machine only has a tilting B and a rotating C-axis. There is no Z axis. Instead, that motion is controlled by a software M code, which has an ON and OFF state either lowering the tool onto the part, or lifting it to its reference position.

Figure 5-1: Set-up on a 2-axis machine for engraving a bowling ball.

The example in Figure 5-2 also shows a simple multiaxis motion so simple that it can be programmed by hand. The program contains the following codes:

<b class="bold">G01 Z2.0000 F90.</b><b class="bold">X-5.5 A2880.000 F50.</b><b class="bold">G00 Z5.</b>

Figure 5-2: A simple multiaxis set-up.

Simultaneous cutting on a 4-axis machine is shown in Figure 5-3, and a set-up for cutting a variable-pitch thread on an auger using 4-axis motions XYZ and A is shown in Figure 5-4.

Figure 5-3: Sketch of simultaneous cutting on a 4-axis machine -XYZA.

Figure 5-4: A 4-axis machine set-up for cutting a variable-pitch thread on an auger using motions on XYZ...