Question

instruction: correct the error(s) in each drawing and explain why it is wrong.
1.
the dimension measured on the drawing is ¾ in., but the actual dimension of the part is 2 in.
2.
3.

Explanation:

Step1: Fix Scale for Drawing 1

First, find the scale factor:
$\text{Scale Factor} = \frac{\text{Actual Dimension}}{\text{Drawing Dimension}} = \frac{2}{\frac{3}{4}} = \frac{8}{3} \approx 2.67$
Update all drawing dimensions by multiplying by the scale factor:

• Original 0.75 in: $0.75 \times \frac{8}{3} = 2$ in
• Original 1.50 in: $1.50 \times \frac{8}{3} = 4$ in
• Original 0.50 in: $0.50 \times \frac{8}{3} \approx 1.33$ in
• Original 0.75 in (height): $0.75 \times \frac{8}{3} = 2$ in
• Original 1.00 in (height): $1.00 \times \frac{8}{3} \approx 2.67$ in

Error: The drawing uses an unstated, incorrect scale; dimensions on the drawing do not match the actual part size, so all dimensions must be scaled to match the 2 in actual height.

Step2: Correct Drawing 2 Dimensions

1. The 0.25 dimension is misplaced: it should dimension the radius of the rounded end (matches R0.25, so align it to the curved edge).
2. The 0.50 height dimension is redundant: the 1.00 overall height defines the total, so remove the 0.50 dimension to avoid duplicate dimensioning.

Error: Misplaced radius dimension and redundant height dimension, which violates technical drawing standards for clarity and accuracy.

Step3: Calculate Missing Dimensions for Drawing3

Substep3.1: Find horizontal missing dimension

$\text{Missing Horizontal} = 1.50 - (2.00 - 1.50) = 1.50 - 0.50 = 1.00$ in

Substep3.2: Find vertical missing dimension

$\text{Missing Vertical} = 1.00 - (1.00 - 0.75) = 1.00 - 0.25 = 0.75$ in
Error: Incomplete dimensioning; the drawing lacks critical dimensions needed to define the part's shape, which is required for manufacturing or interpretation.

Answer:

1. Corrected scaled dimensions for the first drawing: 2 in (0.75 original), 4 in (1.50 original), ~1.33 in (0.50 original), 2 in (0.75 height original), ~2.67 in (1.00 height original). Error: Unmatched scale between drawing and actual part size.
2. Corrected drawing: Move the 0.25 dimension to point to the rounded end, and delete the 0.50 height dimension. Error: Misplaced radius dimension and redundant height dimension.
3. Missing horizontal dimension: 1.00 in; Missing vertical dimension: 0.75 in. Error: Incomplete dimensioning of the part's geometry.