Rhino / Grasshopper setup

  • Download template files from here
  • Open Bark beetle - CNC milling - template.3dm in Rhino

Prepare design in Rhino

  • Create rectangle with size of material to use (click rectangle command and type: start point)
  • Import design in Rhino
  • Fix/adjust design if neccessary (e.g. close shape)

Create rectangle

  • Click rectangle command
  • Enter (type) starting point (e.g. 0,0)
  • Enter width, enter height

Close shape

  • Select lines to join
  • Click join command (Puzzle icon)

Make tabs

  • Create a box (blue cube command) where you want the tab (e.g. 20 mm wide and 2 mm high)
  • Move box downwards until the box bottom and workpiece bottom coincide
  • Copy box to other places where there should be tabs (press option & move)
  • Select all boxes, right click CNC tabs > Change object layer

Create the cutting toolpath next. In the cutting toolpath preview it should be visible that the tabs are not cut

Machining settings in Grasshopper

  • Type grasshopper in command line > Grasshopper window opens > Click on green tile (top left one)
  • Adjust Main settings
    • For multiplex: Material: Hard wood
    • Use inside cutting: yes > cut inside design line
    • Use inside cutting: no > cut outside design line

When using the templates the first time, configure where the generated toolpaths are saved

Screw markers toolpath

  • Create circles with tool diameter & copy to screw positions
  • Set drill depth to 1mm in grasshopper
  • Select all screw circles
  • Right click CNC drill > Change object layer
  • Copy \1 Drill - Bark beetle.NC file from cnc_jobs folder

Other toolpaths

  • Create next toolpath (from inside out) e.g. engrave
  • Right click CNC engrave > Change object layer
  • Copy engrave file from cnc_jobs folder

Sacrificial layer surfacing

To level the sacrificial layer we use a 20 mm tool. By default grasshopper doesn’t have a 20 mm tool in the Bit diameter dropdown. It’s easy to add one with a right click on bit diameter > Edit and then just adding the custom tool to the list

This is some ready GCODE for surfacing with a 20 mm tool. It covers an area of 1230 x 2450 mm. That’s bigger than the MDF plate because it goes 5mm over the edge of the plate all around.