Dust Protection
Since graphite is such an abrasive material, protection of the CNC’s working parts from graphite dust is extremely important. Some machine tool manufacturers have developed turnkey solutions1 that address these application-specific needs.

Look for graphite machines that feature:
Covered linear guidances and ball screws with positive air flow to block abrasive materials from getting into the motion mechanics of the high-speed machining center.
Sealed housings for all motion-control electronics and motors to protect against contamination of the machine control system.
A full enclosure complete with safety lock that is equipped with a connection to an air flow system for dust extraction. This machining system is ideal for machining materials such as graphite, glass-fiber composites, ceramics or any abrasive material.

Tool Length Measurement
Another feature to look for on an advanced machine—which is beneficial in the milling of graphite—is tool length measurement that can compensate for tool wear. This tool sensor/replacer system is made up of three separate components working in conjunction:

Toolchanger
The toolchanger is a rack or tray that has space for spare tools as well as empty sockets for placing broken tools. Machine operators can stock the rack with spare tools, thereby having a ready supply should tools break during lights-out or unattended operation.

Tool checker
The tool checker is a mechanical sensor that measures tool length. This is the instrument that actually detects the worn or broken tool in the first place.

Software
The software is a macro program that can be set up to run a tool check after executing a number of lines of code. For instance, a tool check macro can initiate a check after every 500 lines of code. This is known as an if/then statement, in other words, “Measure this tool; if the length is shorter than the listed parameter, then change the tool.”