Pocket Setup - 3D

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Setup

The main difference between 2D and 3D inlays is the Setup’s Stock Solid is a 3D object. Consider machining this 3D inlay pocket for a tree on the handle of this spatula (from Digital Files: Wok Spatula) The Setup’s stock is set to the original body before the inlay was created (in a case like this, choosing “Create Component” is essential): This means that you should already have machined the 3D shape before you start to create the inlay. In this example, the spatula top has been machined out before the inlay pocket begins:

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Toolpaths

The 3D toolpaths work very differently from the 2D toolpaths, as they have to follow the 3D contours of your target body.

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1. VCarve Outline

This is a 3D Pencil Toolpath in Autodesk Fusion using your VBit to do a VCarve. The important part is the Gemoetry Tab. The Machining Boundary Selection is set to a Sketch Profile, and the Design Sketch in the Pocket component is selected (this is similar to the 2D Pocket’s setup). Tool Containment is set to Center, Additional Offset is set to 0, and Contact Point options are checked.

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2. Clearance Toolpath - Largest Bit

The first clearance toolpath is a 3D Scallop Toolpath. The important part is the Gemoetry Tab. The Machining Boundary Selection is set to the same Sketch Profile as the last toolpath. However, Tool Containment is set to Tool Inside Boundary and an Additional Offset Value is set to a specific number (0.0230” in this example). This value is an Expression, which you can see by clicking the three dots next to it and editing it. The Expression is set to the Parameter pocket_stock_to_leave, which is a basic mathmatical equation based on other parameters: tan(inlay_bit_angle / 2.0) * inlay_depth.

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3. Additional Clearance Toolpaths

Additional clearance toolpaths will be added for each additional smaller diameter bits you checked. The only difference in these toolpaths is they have Rest Machining turned on.

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4. Clearance Rest with VBit

This is another Scallop toolpath setup with the same VBit you initialy picked and it’s purpose is to remove all the material that the previous clearance toolpaths could not get to. It is also constrained by the same Design sketch and has Rest Machining turned on. What is different is the Tool Containment is set to center and the additional offset is -pocket_stock_to_leave (negative pocket stock to leave - which is the same math as before). Fusion treats negative values to be on the inside of a “center” tool containment.

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Multiple Depths or Roughing with Pencil

Most toolpaths have “Multiple Depths”, but Pencil does not. To work around this, right click on the Pencil toolpath and select Duplicate. Rename the first one “VBit Rough”. Double click on it to edit it. On the Passes tab, check** Stock to Leave** and set the Axial Stock to Leave to be half your inlay depth. IE: if your depth is 0.200”, set it to 0.100”. Doing this will generate a light first cut. The plug generally cuts deeper, and you may need to do two roughing passes with varying stock to leave.

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Toolpath Reordering

The default order would be: V-bit, Clearance Bit, V-bit. This causes an unnecessary tool change back to the V-bit at the end. However, moving the last “Clearance Rest with VBit” operation above the Clearance operation will cause it to re-calculate and not be correct (it’d try to remove everything the clearance should be doing). To solve this, you can right click on the V-bit Rest operation and check Protect. It will show Protected via a lock icon. You can then drag the protected toolpath above the Clearance operation.

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VBit First or Clearance First

I prefer to do the v-bit portion first, and finish with the clearance bit. Some people prefer to do the Clearance operation first. If you want to do this, you can just drag the clearance operation(s) before the VBit Outline. If you do that, you won’t have to Protect the V-bit Rest.