Overthickness
Typically, Mastercam will only create a pencil pass where the radius of the filleted material between two surfaces is less than, or equal to, the radius of the tool. Use the Overthickness parameter to make the tool seem bigger than it really is and force a cutting pass where Mastercam otherwise wouldn't create one.
Overthickness is often used when the tool is the same radius, or very close, as the fillets between the surfaces. In these cases, you can get a certain amount of chatter in the toolpath, because at any given point the tool might be seen as slightly larger or smaller than the fillet, depending on the cut tolerance. Using an overthickness value in these situations can eliminate this effect and result in a smooth toolpath along the entire region. For this type of application, we suggest an overthickness value of 10 times the cut tolerance.
The pictures below show how Overthickness is applied to your toolpath. Note that it does not result in either gouging or extra material being left on the part.
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The corner radius of the original tool is smaller than the surface fillet, so —without overthickness— no cutting pass would be created here.
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An overthickness amount is applied to the tool, increasing its corner radius to larger than the surface fillet.
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Mastercam calculates the points where the larger tool would contact the surface.
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The toolpath is projected back onto the surface so that the original tool contacts the surface properly.
To take advantage of this feature by entering an Overthickness amount in the Cut Parameters page for 3D High Speed Pencil toolpaths.
