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4 CNC machining

Date: November 22nd & November 23th, 2016

What we did

Index:

  1. Tasks for this week
    2.
  2. 3D design
  3. CAM software
  4. CNC machines
  5. Experiences
    6.
  6. CNC settings
    7.
  7. References
    8.

  1. Tasks for this week

  2. 3D design
    3. For this assignment I used Autodesk Inventor again.
    image 4_CNC_Design_7
    The final design looks like this.
    image 4_CNC_Design_1
    1. Start with a new *.ipt file and start sketching on the xy-plane.
    image 4_CNC_Design_2
    2. Sketch a 60 mm x 90 mm rectangle and extrude it to 40 mm.
    image 4_CNC_Design_4
    3. Draw another rectangle on top of the block and extrude down in order create an edge.
    image 4_CNC_Design_5
    4. Select the newly created inner surface.
    image 4_CNC_Design_6
    5. Add a text to the surface.
    image 4_CNC_Design_8
    6. Extrude the text sketch and add 2 mm to the text and 5 mm to the corner to respect the minimum radius of the tool. (2 mm turned out to be insufficient as the tool we used was limited to a minium radius of 3 mm.

    4 CNC Part by IngenJoern on Sketchfab

    Export the file as an *.stl-file for prepartion in the CAM software Fusion 360.

  3. CAM software - Fusion 360
    4.  Autodesk Fusion 360 was used as a the CAM software. The computer aided manufacturing software helps in setting up the CNC machine by defining the cutting strategy (e. g. adaptive clearing), defining the tools and the tool path.
    image 4_CNC_clean_mesh
    First the *.stl file has to cleaned up. In the model menu, right click your design and choose "Mesh to BRep".
    image CNC_ModelModifications
    A slide modification had to be made, to enable the tool to fit inside the "A". A cylinder with 3 mm diameter was added.
    image CNC_ChooseCAM
    Choose the CAM menu to setup the manufacturing process.
    image CNC_SpeedSetup
    Click on 3D, adaptive clearing to set up the tool you are going to use.
    image CNC_ChooseTool
    Start with choosing the right tool. In this case, a flat nose milling tool. In the "passes" selection further adjustments can be made. These respect tool and material properties (see Settings section).
    image CNC_Sim
    After clicking ok, Fusion will start the simulation automatically. The toolpath will become visible.
    image CNC_simulate
    By clicking simulate in the actions panel the scroll bar comes up.
    image CNC_SeeProcessingTime
    You can scroll through the job to ensure that it the tool is acting as expected. The approximated time for the job is displayed as well.
    Make sure to set the correct axis orientation in the "geometry" ribbon under "tool orientation". After finishing the setup, choose post processing to generate the G-code. Choose the "Roland CNC" in the post configuration settings.
  4. CNC machine - Roland MDX-40A
    5. image CNC_MDX40A
    Roland MDX-40A CNC machine
    image 4_CNC_ToolMounting
    Before we let the machine run, we have to mount the tool and fix it tightly to the spindle as well as the workspiece to the vise.
    Set the origin point for your workpiece using the axis of the machine. Open the Gcode you just created and choose "cut".

    image 4_CNC_FinishedPart
    Finished part
  5. Experiences
    6.  Make sure to set up "z axis up" in the preferences of Fusion, otherwise your tool will always be oriented in the wrong way. Furthermore, respect the tool diameter in your design as well as the contraints of CNC machines, e. g. limits in inner radius.
  6. CNC settings
    7.
  7. References
    8.
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