Constructing Curves in Oblique Views — Offsets When drawing circles, circular arcs, or other curved features on the receding faces of an oblique projection, is it valid to use offset measurements from the true front view to locate points and reconstruct the curve?

Introduction / Context:
Curved features on oblique faces do not project as true circles unless the plane of the curve is parallel to the sheet. A practical drafting method uses offset coordinates taken from the true view (front face) to map key points, which are then transferred along the receding direction and scaled per the chosen oblique method (e.g., 1/2 depth for cabinet).

Given Data / Assumptions:

• Front face is in true size and shape.
• Rays along the receding axis are parallel and scaled (full or half).
• Offsets can be read from a grid, CAD snaps, or measured coordinates.

Concept / Approach:
By sampling points on the curve in the true view (e.g., 12 o’clock, 3 o’clock, 6 o’clock, 9 o’clock plus intermediate points) and projecting them with the correct depth scale, a smooth, accurate curve is reconstructed on the oblique face. This avoids guesswork and maintains proportional fidelity.

Step-by-Step Solution:
1) Mark key points on the circle/arc in the front view.2) For each point, measure the perpendicular offset to reference axes.3) Transfer offsets to the oblique face, applying depth scale along the receding axis.4) Connect points with a smooth curve; refine with additional samples as needed.

Verification / Alternative check:
Overlay the constructed oblique curve against a CAD ellipse fitted through the projected points; the fit confirms accuracy of the offset method.

Why Other Options Are Wrong:
Incorrect ignores a standard technique. Limits on radius size or angle are unnecessary when offsets are handled properly. Partially correct understates its general applicability.

Common Pitfalls:
Forgetting to apply the cabinet half scale to depth; using too few sample points, yielding a faceted curve.

Final Answer:
Correct