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CNC Checklist

CNC Checklist


  • Open VCarve/Partworks (CAD/CAM program)

  • Open PDF vector file

  • Job setup:

    • Material size: measure your piece, make sure you have room on the edges for screws/clamps

    • Material thickness: use calipers

    • Z Zero at top of material

    • XY Datum position remains in lower left corner

    • Deselect offset

    • In most cases, do not select “scale design with job size”

    • Click Ok

  • Transform and edit options are in left sidebar

  • Toolpath options in tab on right side of window (pin open):

    • Select toolpath operation (ex/ profile toolpath)

    • Start depth usually 0.0”

    • Cut depth: about 0.04” greater than your piece (to cut all the way through)

    • Make sure to select “show toolpath advanced options”

    • Tool:

      • Select appropriate tool (ex/ ¼” straight)

      • Ensure diameter is correct (ex/ 0.25”)

      • Pass depth:  Vertical depth the tool cuts into the material per pass - should never be more than the diameter of the bit

      • Stepover*:  Amount the tool overlaps it’s previous pass (horizontally) - the higher the number, the more it overlaps its last pass and the less new material is cut per pass (more important with pocket toolpaths) - ex/ 50% sufficient for profile toolpaths

      • Spindle speed*:  Revolutions per minute (RPM) of the spindle - depends on the material (ex/ 12000 for ¾” plywood, MDF, OSB and other wood composites

      • Feed rate: How fast the tool travels in the x/y direction (horizontally) - Feed Rate (inches/sec) = RPM x # cutting edges x chipload / 60

        • Chipload is determined from Onsrud Feeds snd Speeeds website - select proper data sheet for your material, select proper tool using series number (left side of table, can be found on tool’s shank) and diameter; select middle value.

      • Plunge rate*: How fast the bit moves in the z direction - no faster than 1” per sec

  • Passes: Automatically determined (cut depth/pass depth, averaged) - usually do not change

  • Tabs: Keep cut pieces attached to sheet so they don’t move.  Select “Add Tabs”, add length and thickness (ex/ 0.5”and 0.5”), select “3D Tabs” if cutting wood and chiseling out later.  Click “Edit Tabs” and use cursor to add them manually.

  • Leads not required

  • Ramps:  Ease the tool into the material, extending the life of the tool. Select “Add Ramps”, and select which type (ex/ smooth).

  • No need to adjust Order or Corners

  • Name toolpath

  • Preview toolpath

  • Save toolpath: .sbp

  • Save VCarve/Partworks file (workflow): .crv

*if filename is too long, the machine can't find the file. Keep .crv filename short

*Changes depending on material and/or tool type - check with staff before attempting metal, plastic, foam, cork, etc

Machine setup

  • Open Shopbot (CAM program)

  • Spindle warmup routine if you’re first to use the machine that day (ask staff)

  • Insert correct collet and tool

  • Large Shopbot only:  Tools -> Spindle RPM Control (ex/ 12000)

  • Small Shopbot only:  Set side Spindle Control Box to proper frequency (Frequency = RPM/60)

  • Clear bed

  • Secure material to bed

  • Zero x and y: Zero -> two axes (x and y)

  • Zero z-axis using z plate: Cuts -> Zero Z-axis with Z plate

  • Turn dust extractor on

  • Safety glasses and hearing protection!

  • Cut Part -> select .sbp file

  • Spacebar to pause, red button for emergency stop