<p>I'm trying to design a camera handle, which will be around 8" long and will have a brass camera thread insert in the end, where the camera will be mounted.  (That way, I don't have to screw the camera thread into plastic which will wear out faster.)</p>

<p>If I print the handle normally, the end of the handle won't be solid so I can't solidly put that brass fitting in.  If I set the fill in Cura to 100%, the print will take a very long time and will be unnecessarily solid.  I only need a centimeter or two at the end to be solid.</p>

<p>Is there a way to get one particular wall in Cura to be very thick (1-2cm) without affecting the other walls?  Is there some other way to get a solid chunk in the end of the part?</p>

I think you are approaching this wrong. Sounds like you need to design it to have a hollow wall. That said to answer your question no you cannot have your slicer modify prints like that. But it bears mentioning you can set all shells to what ever you want have have a very sparse infill. To you can set vertical shells to 3 or so. Top to 3 bottom to 2 and infill to 7-15% so it will be 93% hollow not counting the 3 layers of solid skin.
Post pics of your design. Or let me know what else I can add. Check out my answer to this
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