Machine specifications: The conventional size designation of a shaper machine is based primarily on which parameter?

Introduction / Context:
Machine tools are often classified by a characteristic capacity dimension that tells users what size of work can be accommodated. For shaper machines, the reciprocating ram stroke is the defining capacity measure used in catalogs and shop specifications.

Given Data / Assumptions:

• Conventional, ram-type shaper with adjustable stroke.
• Standard industry naming practice.
• Stroke relates directly to maximum linear travel over the work.

Concept / Approach:
The shaper produces flat surfaces via a linear reciprocating cutting motion. The maximum useful length of cut is bounded by the ram stroke; thus stroke length most directly reflects the largest work length that can be machined in a single pass, making it the logical size designation.

Step-by-Step Solution:

Verification / Alternative check:
Check manufacturer nameplates: models are listed as, for example, “18 in shaper,” indicating 18-inch maximum stroke.

Why Other Options Are Wrong:

• Motor power and machine mass vary with design and accessories, not the principal capacity metric.
• “Rate size” is not a standard term.
• Table width is important but not the conventional shaper size designation.

Common Pitfalls:
Assuming power rating defines size; while it influences capability, capacity naming follows stroke length for shapers.

Final Answer:
stroke length