Blender CAM

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Install

From http://blendercam.blogspot.com/p/download-and-installation.html

Builds are available for Linux, Mac and Windows, and other systems may be supported by following the "Other OS" instructions on that page.

Basic setup

  1. configure "CAM Machine" settings
    1. set machine limits correctly, or conservatively (smaller work area, slower feed rate, etc)
      • The accessible work area of the HackRVA machine is a little larger than 1m x 1m. Setting the Blender CAM limits to 1m x 1m will allow a comfortable ~5cm border on the workspace in which to place and adjust your material.
        • left edge = 118 cm (46.5 in.)
        • back edge = 112 cm (44.25 in.)
        • right edge = 117 cm (46.25 in.)
        • front edge = 114 cm (44.75 in.)
      • The machine "rapid" feed can do 4 meters per minute when not cutting, but a cutting feed should be more like 1 or 2 meters per minute, with a material like pine or fir lumber
      • The DeWalt router spindle RPM ranges from 8,000 (at "1" on the dial) to 23,000 (at 6 on the dial), with 3,000 RPM difference between each number.
    2. Click "+" button to the right of the top drop-down menu in "CAM Machine" pane, to save your settings as a custom machine, perhaps naming it "HackRVA"
  2. build or import your model(s), paying particular attention to scale
  3. make sure all parts of model are in positive X and Y, and negative Z (below the origin)
    • Once the "CAM machine" settings are configured, a dashed box will appear at the world origin that shows where the acceptable cutting area is. Just make sure your model is in that area.
  4. using a group of objects as "Source of data" is handy, allowing components to be added and removed easily.
  5. You may have better luck manually setting CAM Material size and position, as opposed to using "Estimate from model" option. Manually setting size and position may be required for successful CAM chain simulation, as variations in material size and position settings will cause operations to be applied to the displacement image at different scales.

To define a CAM operation

  1. click "+" button to the right of the "CAM operations" selection box (the button is just above the little clipboard button)
  2. set "Operation Name" and "File Name" just under the selection box
  3. select from the many cutting options....

to restrict the operation to an area, enable "Use limit curve"

In the "CAM operation area" section, enable "Use limit curve", instead of changing "CAM Material size and position" settings.

  1. draw a curve in the XY plane to define the area. In no case does this curve need to be included in the "Source of data" group.
  2. you can also use mesh objects, like a plane, then use "Convert to curve" (ALT-C) and select "Curve" as the result. This simplifies defining areas with straight edges.
  3. select the curve object in the "Limit Curve" drop-down menu

if model is larger than CAM machine "work area"

If your model is larger than CAM machine "work area" (e.g., if you'll be routing out the full model in two or more stages), select "Ambient: All" in "CAM operation area" section, to have BlenderCAM ignore the extra model. Otherwise you may get a complete failure to generate a cutting path, or simulating the operation can fail.

To generate a path with a custom tool

To generate a cutting path for a tool that isn't "ball", "end" or "chamfer":

  1. Build a mesh object that represents the cutting shape of the custom tool
    • once the model is built, reset the model's rotation (ALT-R) (and possibly scale ([ALT-S])and position ([ALT-G])...), then enter Edit Mode ([TAB]), and make sure all points of the model are above the object's origin. You can also restore any desired scale, rotation and position while in Edit Mode. Then tap [TAB] to exit Edit Mode.
    • There may be a very low limit to the number of faces that the cutting tool can use, resulting in a path with no Z-position changes
    • some orientations of the tool object can cause path creation failure
    • Blender Cam doesn't spin the custom tool object
      • To simulate a spinning tool, build the object from a cylinder, extrude one end of the cylinder and change the extruded vertices' radius.
      • possibly interesting cutting effects can be achieved by modeling a standard tool, and distorting the cutting surfaces.
  2. Set "Cutter diameter" in "CAM Cutter" section
  3. Enabling "Use exact mode" in the "CAM optimization" section might be a way to avoid failing path generation?

To simulate an operation

  1. run "Calculate Path", so the operation appears in the Outliner panel (it will be named "cam_path_***")
  2. click "Simulate this operation"
  3. If a blank, flat gray plane appears, you'll need to select the operation to simulate in the "CAM Simulation" pane, at the bottom of the same pop-out panel as "Object Tools"
  • If the resulting simulation is too coarse, either increase the number of subdivisions on the "Subdivision Surface" modifier, in the Modifiers panel, or add "face loops" in Edit Mode.
  • If the simulation generates a long rectangle, the quality can be improved by adding "face loops" in Edit Mode to split the long rectangle into multiple squares.

To make a CAM chain

  1. define each operation, and run "Calculate Path" for each, so they appear as "cam_path_*" in the outliner
    • if you will want to simulate the CAM chain, make sure to set "Simulation sampling raster data" to the same value in all operations, e.g. "0.5mm", before running "Calculate Path". Otherwise the various operations will appear at different scales on the generated displacement image.
    • also if you want to simulate the CAM chain, make sure that all operations have the same "CAM Material size and position" settings.
  2. add a new CAM chain (click the "+" button to the right of the upper selection box(?))
  3. set Chain Name and File Name
  4. for each operation to include in the chain:
    1. click operation name in "Cam operations" selection box
    2. click "+" button next to 2nd selection box (just above "Export chain gcode" button)
  5. click "Export chain gcode" button to save the concatenated operations to a file

to simulate a CAM chain

  1. make a CAM chain, including exporting chain gcode
  2. click "Simulate this chain" button