Trim and knit surfaces in Solidworks - Real Business Scenario

Scenario Mode

👤 Your Role: You are a product design analyst at a manufacturing company.

📋 Request: Your manager wants you to analyze the surface modeling process to improve the efficiency of creating complex 3D parts using Trim and Knit surfaces in SolidWorks.

📊 Data: You have access to a dataset that records the time taken, number of surfaces trimmed, and number of surfaces knitted for various parts designed over the last month.

🎯 Deliverable: Create a report showing the average time spent on trimming and knitting surfaces per part, and visualize the relationship between the number of surfaces trimmed and knitted.

Sample Data

Part ID	Surfaces Trimmed	Surfaces Knitted	Time Trimming (min)	Time Knitting (min)
P001	5	3	12	8
P002	7	4	15	10
P003	4	2	10	6
P004	6	5	14	12
P005	3	3	9	7
P006	8	6	18	14
P007	5	4	13	9
P008	7	5	16	11

1

Step 1: Calculate the average time spent trimming surfaces per part.

Average Time Trimming = SUM(Time Trimming (min)) / COUNT(Part ID)

Expected Result

Average Time Trimming = (12+15+10+14+9+18+13+16) / 8 = 13.375 minutes

2

Step 2: Calculate the average time spent knitting surfaces per part.

Average Time Knitting = SUM(Time Knitting (min)) / COUNT(Part ID)

Expected Result

Average Time Knitting = (8+10+6+12+7+14+9+11) / 8 = 9.625 minutes

3

Step 3: Create a scatter plot with 'Surfaces Trimmed' on the X-axis and 'Surfaces Knitted' on the Y-axis to visualize their relationship.

Plot points: (5,3), (7,4), (4,2), (6,5), (3,3), (8,6), (5,4), (7,5)

Expected Result

Scatter plot showing positive correlation between surfaces trimmed and knitted.

4

Step 4: Create a bar chart showing average time spent trimming and knitting surfaces.

Bar chart with two bars: 'Average Time Trimming' = 13.375 min, 'Average Time Knitting' = 9.625 min

Expected Result

Bar chart clearly showing trimming takes more time on average than knitting.

5

Step 5: Summarize findings in a report highlighting the average times and the correlation between trimmed and knitted surfaces.

Write summary text based on calculated averages and scatter plot insights.

Expected Result

Report stating trimming takes about 13.4 minutes on average, knitting about 9.6 minutes, and more surfaces trimmed generally means more surfaces knitted.

Final Result

Trimming

↓

Knitting

✓On average, trimming surfaces takes about 13.4 minutes per part.

✓Knitting surfaces takes about 9.6 minutes per part on average.

✓There is a positive relationship between the number of surfaces trimmed and knitted.

✓Parts with more trimmed surfaces tend to have more knitted surfaces.

Bonus Challenge

Create a calculated measure to find the average time spent per surface (trimming and knitting combined) for each part.

Show Hint

Calculate total time per part (Time Trimming + Time Knitting) divided by total surfaces (Surfaces Trimmed + Surfaces Knitted).

Practice

1.

What is the main purpose of the Trim tool in SolidWorks surface modeling?

easy

A. To cut surfaces to a desired shape

B. To join multiple surfaces into one

C. To create new solid bodies directly

D. To add thickness to surfaces

Solution

1. Step 1: Understand the function of Trim

   The Trim tool is used to cut or remove parts of surfaces to get the shape you want.

2. Step 2: Differentiate from other tools

   Knit joins surfaces, and adding thickness is done by other features, so Trim specifically cuts surfaces.

3. Final Answer:

   To cut surfaces to a desired shape -> Option A

4. Quick Check:

   Trim = Cutting surfaces [OK]

Hint: Trim cuts surfaces; think of scissors cutting paper [OK]

Common Mistakes:

• Confusing Trim with Knit which joins surfaces
• Thinking Trim creates solids directly
• Assuming Trim adds thickness

2.

Which of the following is the correct sequence to create a solid from multiple surfaces in SolidWorks?

1. Knit surfaces
2. Trim surfaces
3. Use Knit with 'Create solid' option

easy

A. Trim surfaces, then Knit surfaces with 'Create solid' option

B. Knit surfaces, then Trim surfaces, then create solid

C. Create solid first, then Trim and Knit surfaces

D. Use Knit surfaces with 'Create solid' option after trimming

Solution

1. Step 1: Trim surfaces to desired shape

   First, use Trim to cut surfaces to the correct shape.

2. Step 2: Knit trimmed surfaces with 'Create solid'

   Then, knit the trimmed surfaces and select the 'Create solid' option to form a solid body.

3. Final Answer:

   Use Knit surfaces with 'Create solid' option after trimming -> Option D

4. Quick Check:

   Trim then Knit with solid option = C [OK]

Hint: Trim first, then Knit with 'Create solid' checked [OK]

Common Mistakes:

• Trying to create solid before trimming
• Knitting before trimming without solid option
• Trimming after knitting

3.

Given three overlapping surfaces, you trim one surface to remove the overlap, then knit all three surfaces with the 'Create solid' option checked. What is the expected result?

medium

A. A single solid body formed from the knit surfaces

B. Separate surfaces remain, no solid created

C. An error message about overlapping surfaces

D. Only the trimmed surface becomes a solid

Solution

1. Step 1: Trim removes overlapping parts

   Trimming one surface removes overlap, so surfaces fit together cleanly.

2. Step 2: Knit with 'Create solid' joins surfaces into solid

   Knitting all surfaces with the solid option creates one solid body from the joined surfaces.

3. Final Answer:

   A single solid body formed from the knit surfaces -> Option A

4. Quick Check:

   Trim + Knit solid = one solid body [OK]

Hint: Trim overlaps first, then knit with solid option for one solid [OK]

Common Mistakes:

• Expecting separate surfaces after knitting
• Ignoring overlap causing knit failure
• Assuming only trimmed surface becomes solid

4.

You tried to knit several surfaces but got an error saying the surfaces do not form a closed volume. What is the most likely cause?

medium

A. The Knit tool was used before trimming surfaces

B. Some surfaces overlap and were not trimmed properly

C. The 'Create solid' option was not selected

D. The surfaces are already solids

Solution

1. Step 1: Understand knit error cause

   The error about not forming a closed volume usually means surfaces overlap or gaps exist.

2. Step 2: Check trimming of surfaces

   If surfaces overlap and are not trimmed, they cannot form a closed volume when knitted.

3. Final Answer:

   Some surfaces overlap and were not trimmed properly -> Option B

4. Quick Check:

   Overlap without trimming causes knit error [OK]

Hint: Trim overlaps before knitting to avoid closed volume errors [OK]

Common Mistakes:

• Assuming 'Create solid' option fixes volume errors
• Knitting before trimming is always wrong
• Thinking surfaces already solids cause knit errors

5.

You have a complex model with multiple intersecting surfaces. You want to create a single solid body. Which sequence of actions is best?

1. Trim intersecting surfaces to remove overlaps
2. Knit all trimmed surfaces with 'Create solid' option
3. Check for gaps and fill if needed before knitting

hard

A. Fill gaps first, then trim and knit surfaces without solid option

B. Knit surfaces first, then trim overlaps and fill gaps

C. Trim surfaces, fill gaps, then knit with 'Create solid' option

D. Create solid first, then trim and knit surfaces

Solution

1. Step 1: Trim intersecting surfaces

   Remove overlaps by trimming so surfaces fit together cleanly.

2. Step 2: Fill any gaps between trimmed surfaces

   Check and fill gaps to ensure surfaces form a closed volume.

3. Step 3: Knit all surfaces with 'Create solid' option

   Join surfaces into one solid body after trimming and gap filling.

4. Final Answer:

   Trim surfaces, fill gaps, then knit with 'Create solid' option -> Option C

5. Quick Check:

   Trim + fill gaps + knit solid = solid body [OK]

Hint: Trim, fill gaps, then knit with solid option for best results [OK]

Common Mistakes:

• Knitting before trimming or filling gaps
• Ignoring gaps causing knit failure
• Trying to create solid before cleaning surfaces