Many know that Post Processors are critical and 5 Axis machining is a goal many wish to better understand. Below is a series of terms and general knowledge that is critical to mastering multi-axis and 5 Axis machining
Cartesian coordinate system
For right-handed linear coordinates,
The positive X Axis is represented by the direction of your thumb
The positive Y Axis is represented by the direction of your right index
finger
The positive Z Axis is represented by the direction of your middle finger
Rotational Axis Systems
For right-handed Rotational Axis,
The A Axis rotates around the X Axis.
The B Axis rotates around the Y Axis.
The C Axis rotates around the Z Axis.
The positive direction of rotation is counter-clockwise
when looking down the positive direction of the respective Axis
Tool Direction Vectors
Tool Vectors consist of two points
P1 represents the tool tip in XYZ
P2 represents the tool direction in IJK incremental from P1tool tip
When Tool is Vertical the vector is I0.0 J0.0 K1.0
IJK values are incremental values respective to XYZ.
I = X J = Y K = Z
Tool Direction Vectors
Tool Vectors consist of two points
P1 represents the tool tip in XYZ
P2 represents the tool direction in IJK incremental from P1tool tip
When Tool is Vertical the vector is I0.0 J0.0 K1.0
IJK values are incremental values respective to XYZ.
I = X J = Y K = Z
Azimuth & Elevation
Tool Direction
Azimuth & Elevation are common terms to define a direction is space. In the mechanical world
Azimuth is the rotation around the principal axis (Usually
Z)
Elevation is the angle of Tilt from the product of that Axis (Usually the XY plane)
Thinking of a HEAD – HEAD style machine, Azimuth is similar of a C Axis (but not specifically) and Elevation would be the tilt of the Tool
Euler Angles
Definition of machining plane through three rotations
There many combinations of Euler Conventions
The Euler angles are three angles introduced by Leonhard Euler to
describe the orientation of a rigid body with respect to a
fixed coordinate system.
Credit https://en.wikipedia.org/wiki/Euler_angles
RTCP
RTCP – Rotational Tool Compensation Point. Sometimes referred to as TCP.
The image left is when a machine does not have RTCP or it is turned off. The tool when it rotates may violate the part as it rotates.
RTCP
RTCP – Rotational Tool Compensation Point. Sometimes referred to as TCP.
The image to the right shows what happens when RTCP is active. The machine mill adjust or compensate the linear axis so that when the tool rotates it stays in the same relative position to the part as is intended.
RTCP is critical for high quality surface finishes and easier 5 Axis proframming