Tutorial – Preparing your model in Rhino for CNC milling (From 3D model to CNC fabrication, part 2)

This tutorial showcases an example of preparations in Rhino to make your model suitable for CNC milling, in the context of aiming to utilize the CNC router in the KTH Architecture school Workshop.

Timestamps:
0:00 You want a single closed solid polysurface, identical to what you intend to mill
1:12 Adhering to the limitations of three-axis CNC milling
1:30 Good procedure to work in a separate file, and necessary to work in mm
1:43 Scale the model to its intended fabrication scale
2:46 Make a stock bounding box, reflecting the height of the milled material
4:32 Straight method of converting open polysurface to closed and solid
5:16 Tapered method of converting open polysurface to closed and solid
10:44 Achieve a rotation of the model so that the entailing stock bounding box is material-efficient, as well as corresponding with the orientation of the axes of the CNC machine
12:58 Offset the lateral sides of the material stock, to give more headroom for placement errors during milling
14:23 Add 3 mm of unmilled material in the bottom of the model, to prevent ruptions of the vacuum suction
15:14 Place the model correctly with regards to the origin point
15:37 Export the model as a Rhino 5 file
16:28 Outro

Please note that the 3 mm bottom margin is not necessary if you mill with a sufficiently dimensioned spoilerboard – when milling with a spoilerboard, it is of utmost important to place the vacuum sealing strips correctly underneath the milled model, which is equally important but more difficult than without a spoilerboard, since the spoilerboard blocks the visibility of them, and when milling all the way through the stock material, the vacuum sealing strips must be places in such a way that they retain the vacuum suction for the final milled model, and not only the unmilled stock material. For organic shapes such as the one in this example, it is thus a sensible choice to include the 3 mm bottom margin to reduce the risk of vacuum suction ruption, and for non-organic, rectilinear shapes, it is more straightforward to include the same margin due to it being a trivial matter to cut away manually after the milling of the surface.

Google Drive folder with KTH community resources:
https://drive.google.com/drive/folder...

This tutorial is part of a series, "From 3D model to CNC fabrication":
Playlist link:
   • KTH Tutorials – CNC – From 3D model t...  
Part 1: The limitations of three-axis CNC milling
   • Видео  
Part 2: Preparing your model in Rhino for CNC milling
   • Tutorial – Preparing your model in Rh...  
Part 3: Obtaining Educational Access to Fusion 360
   • Tutorial – Obtaining Educational Acce...  
Part 4: Importing into Fusion 360 and setting up stock
   • Tutorial – Importing into Fusion 360 ...  
Part 5: Importing a tool library into Fusion 360
   • Tutorial – Importing a tool library i...  
Part 6: Authoring a clearance toolpath in Fusion 360
   • Tutorial – Authoring a clearance tool...  
Part 7: Authoring a roughing toolpath in Fusion 360
   • Tutorial – Authoring a roughing toolp...  
Part 8: Authoring a finishing toolpath in Fusion 360
   • Tutorial – Authoring a finishing tool...  
Part 9: Post-processing toolpaths in Fusion 360
   • Tutorial – Post-processing toolpaths ...  
Part 10: Preparing your physical stock for CNC milling
   • Tutorial – Preparing your physical st...  
Part 11: Initializing the CNC machine and setup tools
   • Tutorial – Initializing the CNC machi...  
Part 12: Calibrating tools and defining work origin
   • Tutorial – Calibrating tools and defi...  
Part 13: Executing the toolpaths and cleaning up
   • Tutorial – Executing the toolpaths an...  

Disclaimer:
This tutorial aims to increase student awareness of the versatility of the digital tools available for use within the context of the architectural education offered by KTH. As such, it might not be generally applicable, but on the other hand, if even one student is helped by it with fulfilling deliverables requirements, the purpose of this tutorial is satisfactorily achieved. There might be inaccuracies in this tutorial video – if you identify any significant one, please tell us in the comments.