FANUC Tool Center Point Control: checking the machine, tools and postprocessor
TCP coordinates the intended toolpath with the movement of individual machine axes. For systems configured with the function, this article explains how the program, machine kinematics, tool data and postprocessor must correspond, and highlights common selection mistakes.
Contents
In multi-axis machining, a program can describe the positions the tool should reach or directly describe the movements of individual axes. Do not mix these approaches without checking their compatibility. Understanding TCP is less about memorizing a command name than confirming that the program representation, controller function and machine kinematics agree.
Meaning and applicability
FANUC’s integrated five-axis technology information explains TCP as a basic function in which the controller determines the required axis movements from the desired tool position, and emphasizes coordination among the CNC, CAD/CAM and postprocessor. The official 31i-B product page lists tool center point control. This is a model-level capability reference, not proof that every machine using that controller has the same completed configuration.
This article concerns multi-axis machines whose TCP application conditions need checking. Consult the machine-specific manual for the software series, function type and command format. Do not directly transfer 31i-B descriptions to other series. No steps for bypassing the machine builder’s configuration are provided.
Prepare four corresponding sets of information
- Machine kinematics: Which axes move linearly and which rotate the tool or table? How are their names, positive directions and travel ranges defined?
- Tool information: Do the programmed tool, actual installed length and compensation data agree, and who maintains the measurement records?
- Program and postprocessor: Identify the coordinate, orientation and compensation conventions used in the output, and retain the postprocessor name and version.
- Controller configuration: Confirm the model, software version, functions actually available and the machine builder’s instructions for that combination.
Use a scenario to test the assumptions
Suppose the same part is transferred from a machine with a swiveling head to a rotary-table machine. Even with the same machining objective, the axis relationships may differ. Recheck the postprocessor and machine definition; the fact that both machines use FANUC or display TCP does not make the original program ready for production. This is a configuration-checking example, not a validated program-transfer plan.
Similarly, after changing tool length, verify the compensation data and how the program uses it under the machine’s procedure. “The controller calculates it automatically” is not a reason to omit tool-data checks. If the model or inputs do not agree, the calculation alone does not establish that its result suits the physical machine.
Separate function acceptance from machining acceptance
Function acceptance checks the actual configuration against expected behavior. Machining acceptance concerns paths, dimensions and surface results with the specified part, workholding and tools. Start with a simulation model matching the real machine, then have qualified personnel complete on-machine validation under the manufacturer’s procedure, retaining the versions and results.
TCP is not synonymous with every multi-axis function, and does not replace workholding and collision checks. For tilted-plane programming, see TWP and 3+2 machining checks; further material is in the OPTION section.