Bend radius and bend allowance in Solidworks - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to calculate the bend allowance.

Solidworks

bend_allowance = [1] * bend_angle * (pi / 180)

Drag options to blanks, or click blank then click option'

Ak_factor

Bbend_radius

Cmaterial_thickness

Dbend_angle

Attempts:

3 left

💡 Hint

Common Mistakes

Using material thickness instead of bend radius.

The bend allowance is calculated using the bend radius, bend angle, and pi. Here, the bend radius is needed.

2fill in blank

medium

Complete the code to calculate the neutral axis location using the K-factor.

Solidworks

neutral_axis = [1] * material_thickness

Drag options to blanks, or click blank then click option'

Abend_allowance

Bbend_radius

Ck_factor

Dbend_angle

Attempts:

3 left

💡 Hint

Common Mistakes

Using bend radius instead of K-factor.

The neutral axis location is found by multiplying the material thickness by the K-factor.

3fill in blank

hard

Fix the error in the bend allowance formula.

Solidworks

bend_allowance = [1] * bend_angle * (pi / 180)

Drag options to blanks, or click blank then click option'

Abend_radius

B2 * bend_radius

Cmaterial_thickness

Dk_factor

Attempts:

3 left

💡 Hint

Common Mistakes

Using 2 * bend_radius instead of bend_radius.

The correct formula multiplies bend radius by the bend angle in radians.

4fill in blank

hard

Fill both blanks to calculate the flat length of a bent part.

Solidworks

flat_length = [1] + [2]

Drag options to blanks, or click blank then click option'

Aoutside_leg_length

Bbend_allowance

Cinside_leg_length

Dneutral_axis

Attempts:

3 left

💡 Hint

Common Mistakes

Using outside leg length instead of inside leg length.

The flat length is the sum of the inside leg length and the bend allowance.

5fill in blank

hard

Fill all three blanks to calculate the bend deduction.

Solidworks

bend_deduction = [1] + [2] - [3]

Drag options to blanks, or click blank then click option'

Aoutside_leg_length

Binside_leg_length

Cbend_allowance

Dneutral_axis

Attempts:

3 left

💡 Hint

Common Mistakes

Subtracting neutral axis instead of bend allowance.

Bend deduction is calculated by adding outside and inside leg lengths and subtracting the bend allowance.

Practice

1. What does the bend radius represent in sheet metal design?

easy

A. The inside curve size of the bend

B. The thickness of the sheet metal

C. The total length of the flat pattern

D. The angle of the bend

Solution

1. Step 1: Understand bend radius definition

   Bend radius is the radius of the inside curve where the metal bends.

2. Step 2: Differentiate from other terms

   Thickness is metal thickness, length is flat pattern size, angle is bend angle, so they are incorrect.

3. Final Answer:

   The inside curve size of the bend -> Option A

4. Quick Check:

   Bend radius = inside curve size [OK]

Hint: Bend radius is always the inside curve size [OK]

Common Mistakes:

• Confusing bend radius with metal thickness
• Thinking bend radius is the bend angle
• Mixing bend radius with flat pattern length

2. Which of the following formulas correctly represents bend allowance (BA) for a bend with angle θ (in degrees), bend radius R, and thickness T?

easy

A. BA = (π/180) x θ x (R + T/2)

B. BA = (π/180) x θ x (R - T/2)

C. BA = (π/180) x θ x (R + T)

D. BA = (π/180) x θ x R

Solution

1. Step 1: Recall bend allowance formula

   Bend allowance = angle in radians x (bend radius + half thickness).

2. Step 2: Convert angle to radians and apply formula

   Angle θ in degrees converted by (π/180), then multiplied by (R + T/2).

3. Final Answer:

   BA = (π/180) x θ x (R + T/2) -> Option A

4. Quick Check:

   Bend allowance = angle x (radius + half thickness) [OK]

Hint: Add half thickness to radius in bend allowance formula [OK]

Common Mistakes:

• Using full thickness instead of half thickness
• Omitting thickness in the formula
• Using radius minus half thickness

3. Given a sheet metal bend with bend radius 7 mm, thickness 2 mm, and bend angle 90°, what is the bend allowance using the formula BA = (π/180) x θ x (R + T/2)? (Use π ≈ 3.14)

medium

A. 10.5 mm

B. 12.56 mm

C. 15.7 mm

D. 13.23 mm

Solution

1. Step 1: Calculate (R + T/2)

   R = 7 mm, T = 2 mm, T/2 = 1 mm, so R + T/2 = 8 mm.

2. Step 2: Convert 90° to radians

   (3.14 / 180) x 90 ≈ 0.01744 x 90 ≈ 1.57 radians.

3. Step 3: Compute bend allowance

   BA = 1.57 x 8 = 12.56 mm.

4. Final Answer:

   12.56 mm -> Option B

5. Quick Check:

   (π/180) x 90 x 8 ≈ 12.56 mm [OK]

Hint: Multiply angle in radians by (radius + half thickness) [OK]

Common Mistakes:

• Forgetting to convert angle to radians
• Using full thickness instead of half thickness
• Incorrect π value or rounding errors

4. Identify the error in this bend allowance calculation code snippet:

angle = 90
radius = 5
thickness = 2
bend_allowance = (3.14 / 180) * angle * (radius - thickness / 2)

medium

A. Thickness should be doubled, not halved

B. Angle should be in radians, not degrees

C. Using radius minus half thickness instead of adding

D. π value is incorrect

Solution

1. Step 1: Review bend allowance formula

   Correct formula uses (radius + half thickness), not minus.

2. Step 2: Check code snippet

   Code uses (radius - thickness / 2), which is incorrect and will underestimate bend allowance.

3. Final Answer:

   Using radius minus half thickness instead of adding -> Option C

4. Quick Check:

   Bend allowance uses radius + half thickness [OK]

Hint: Always add half thickness to radius in formula [OK]

Common Mistakes:

• Subtracting half thickness instead of adding
• Not converting angle to radians
• Using wrong π value

5. You need to create a flat pattern for a sheet metal part with a 120° bend, bend radius 4 mm, and thickness 1 mm. Which bend allowance should you use to ensure accurate flat length?

hard

A. BA = (π/180) x 90 x (4 + 1/2) = 7.07 mm

B. BA = (π/180) x 120 x (4 - 1/2) = 7.54 mm

C. BA = (π/180) x 180 x (4 + 1) = 15.7 mm

D. BA = (π/180) x 120 x (4 + 1/2) = 9.42 mm

Solution

1. Step 1: Identify correct formula and values

   Use BA = (π/180) x angle x (radius + half thickness). Angle = 120°, radius = 4 mm, thickness = 1 mm.

2. Step 2: Calculate bend allowance

   Half thickness = 0.5 mm, so radius + half thickness = 4.5 mm.
   BA = (3.14/180) x 120 x 4.5 ≈ 2.09 x 4.5 = 9.42 mm.

3. Final Answer:

   BA = (π/180) x 120 x (4 + 1/2) = 9.42 mm -> Option D

4. Quick Check:

   Bend allowance uses angle 120° and radius + half thickness [OK]

Hint: Use angle x (radius + half thickness) for bend allowance [OK]

Common Mistakes:

• Using wrong bend angle
• Subtracting half thickness
• Doubling thickness instead of halving