When possible, installing the cutter on a shaper should shape which part of the stock?

• A. Top of stock
• B. Bottom of stock is shaped
• C. Faces are flat
• D. Sides are shaped

Answer: (B)

The main idea is about protecting the face that will be seen after assembly. On a shaper, material is removed from the surface that the cutter engages as the stock is fed under the cutter head. By shaping the bottom of the stock first, you establish the desired contour on a surface that is typically hidden or less critical to the finished appearance, while keeping the top surface flat and ready for final finish or precise fit. This minimizes the chance of leaving visible marks or tear-out on the face that will be seen, and it also helps control thickness with a stable reference surface.

Shaping the top would risk marring the surface you want to keep clean and true, and shaping the sides or faces doesn’t align with the common practice of defining a bottom contour first to preserve the intended top surface and overall dimensions.