Difficulty: Easy
Correct Answer: 0° to 8°
Explanation:
Introduction / Context:
Centreless grinding achieves high production rates by supporting the work between a grinding wheel and a regulating (control) wheel without centers. The regulating wheel speed and inclination govern the through-feed rate and work stability.
Given Data / Assumptions:
Concept / Approach:
Tilting the regulating wheel by a small angle α relative to the grinding wheel axis creates a component of the regulating wheel surface velocity along the work axis. This component feeds the work through the machine. Typical α is a few degrees; excessive angles can destabilize the work and degrade roundness or surface finish.
Step-by-Step Solution:
Define α as the inclination of the regulating wheel axis to the work axis.Recognize standard practice: α kept small to control feed smoothly.Typical range used industrially: about 2° to 8°, hence the best matching choice is 0° to 8°.
Verification / Alternative check:
Setup manuals specify low single-digit degrees for the regulating wheel angle to balance feed with roundness control.
Why Other Options Are Wrong:
Higher ranges (9°–15° or more) are atypical and can cause instability, poor finish, or loss of control. Very large angles are not used for through-feed centreless grinding.
Common Pitfalls:
Confusing the regulating wheel tilt with work-rest blade angle or height; both affect roundness but serve different purposes.
Final Answer:
0° to 8°
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