The CNC Chef: Toolpath tips | Episode 6

Published Date
August 03, 2017 - 02:30:pm

Bob Warfield from CNCCookbook discusses some toolpath tips to help you get the most from your CAM software in the sixth episode of The CNC Chef, a video series produced in collaboration with Cutting Tool Engineering.

Warfield added the following explanation in response to some who viewed this episode of The CNC Chef and commented that the labels on the deflection diagram suggest climb milling does not push the cutter into the cut while conventional milling does.


Remember, the cutter moves left to right on both Conventional and Climb Cuts. With that in mind, let’s look at the force vectors, which show the direction of deflection. Virtually all of the conventional vectors face left. In other words, they face away from the direction of feed. In that sense, they’re pulling away from the cut, rather than deflecting into the cut.

The force vectors for climb milling, in comparison, mostly face right, which is the direction of feed. They are deflecting into the cut and and thereby intensifying the cutting action.

Now granted, the length of the vectors is less for climb than conventional. That means the forces are lower and there is likely to be less deflection. That’s why I say in the video that you’re really going to have to test which one works better.

About The CNC Chef Video Series: Bob Warfield founded and built it up to be one of the most popular CNC Blogs on the Internet. Thanks to his work with CNCCookbook and the G-Wizard software series, Warfield routinely receives questions from shops all over the world. For more information about the CNC Chef, visit his website here.

Related Glossary Terms

  • climb milling ( down milling)

    climb milling ( down milling)

    Rotation of a milling tool in the same direction as the feed at the point of contact. Chips are cut to maximum thickness at the initial engagement of the cutter’s teeth with the workpiece and decrease in thickness at the end of engagement. See conventional milling.

  • computer numerical control ( CNC)

    computer numerical control ( CNC)

    Microprocessor-based controller dedicated to a machine tool that permits the creation or modification of parts. Programmed numerical control activates the machine’s servos and spindle drives and controls the various machining operations. See DNC, direct numerical control; NC, numerical control.

  • computer-aided manufacturing ( CAM)

    computer-aided manufacturing ( CAM)

    Use of computers to control machining and manufacturing processes.

  • conventional milling ( up milling)

    conventional milling ( up milling)

    Cutter rotation is opposite that of the feed at the point of contact. Chips are cut at minimal thickness at the initial engagement of the cutter’s teeth with the workpiece and increase to a maximum thickness at the end of engagement. See climb milling.

  • feed


    Rate of change of position of the tool as a whole, relative to the workpiece while cutting.

  • gang cutting ( milling)

    gang cutting ( milling)

    Machining with several cutters mounted on a single arbor, generally for simultaneous cutting.

  • milling


    Machining operation in which metal or other material is removed by applying power to a rotating cutter. In vertical milling, the cutting tool is mounted vertically on the spindle. In horizontal milling, the cutting tool is mounted horizontally, either directly on the spindle or on an arbor. Horizontal milling is further broken down into conventional milling, where the cutter rotates opposite the direction of feed, or “up” into the workpiece; and climb milling, where the cutter rotates in the direction of feed, or “down” into the workpiece. Milling operations include plane or surface milling, endmilling, facemilling, angle milling, form milling and profiling.

  • toolpath( cutter path)

    toolpath( cutter path)

    2-D or 3-D path generated by program code or a CAM system and followed by tool when machining a part.


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