Why Shell feature for hollow parts in Solidworks? - Purpose & Use Cases

The Big Idea

Discover how one simple feature can save hours of tedious work and prevent costly design mistakes!

The Scenario

Imagine you need to create a hollow plastic container by manually modeling every wall thickness and cavity inside your 3D design.

You try to build each inner surface one by one, adjusting thicknesses and ensuring the shape stays consistent.

The Problem

This manual method is slow and frustrating because you must carefully create each inner face, which takes a lot of time and is easy to mess up.

Small mistakes can cause the part to be too thick or thin, leading to manufacturing problems.

The Solution

The Shell feature lets you hollow out a solid part automatically by specifying a uniform wall thickness.

This saves time and reduces errors by creating consistent walls inside your design with just a few clicks.

Before vs After

✗ Before

Create inner surfaces manually
Adjust thickness for each wall
Check for errors

✓ After

Apply Shell feature
Set wall thickness
Generate hollow part automatically

What It Enables

You can quickly create complex hollow parts with precise wall thickness, ready for manufacturing or simulation.

Real Life Example

Designing a lightweight phone case that needs to be hollow inside to save material but strong enough on the outside.

Key Takeaways

Manual hollowing is slow and error-prone.

Shell feature automates hollowing with consistent thickness.

It speeds up design and improves part quality.

Practice

1.

What is the main purpose of the Shell feature in SolidWorks?

easy

A. To hollow out a solid part by removing internal material

B. To add extra thickness to a solid part

C. To combine two solid parts into one

D. To create a new solid part from a sketch

Solution

1. Step 1: Understand the Shell feature function

   The Shell feature removes internal material from a solid part, leaving a hollow shell with specified wall thickness.

2. Step 2: Compare options with the Shell feature purpose

   Only To hollow out a solid part by removing internal material correctly describes hollowing out a solid part by removing inside material.

3. Final Answer:

   To hollow out a solid part by removing internal material -> Option A

4. Quick Check:

   Shell feature = hollow part creation [OK]

Hint: Shell feature hollows parts by removing inside material [OK]

Common Mistakes:

• Confusing Shell with adding thickness
• Thinking Shell combines parts
• Assuming Shell creates new solids from sketches

2.

Which of the following is the correct way to specify wall thickness when using the Shell feature?

easy

A. Enter the thickness value in the Shell property manager before selecting faces to remove

B. Draw a sketch of the thickness and extrude it

C. Use the Fillet tool to set thickness

D. Apply a material color to indicate thickness

Solution

1. Step 1: Identify how wall thickness is set in Shell feature

   Wall thickness is entered as a numeric value in the Shell property manager before removing faces.

2. Step 2: Eliminate incorrect options

   Options B, C, and D do not relate to setting wall thickness in Shell feature.

3. Final Answer:

   Enter the thickness value in the Shell property manager before selecting faces to remove -> Option A

4. Quick Check:

   Wall thickness input = Enter the thickness value in the Shell property manager before selecting faces to remove [OK]

Hint: Set thickness in Shell property manager before removing faces [OK]

Common Mistakes:

• Trying to set thickness via sketches
• Using unrelated tools like Fillet
• Confusing color with thickness

3.

Given a solid cube of 100mm edge length, you apply a Shell feature with 5mm wall thickness and remove the top face. What is the height of the hollow part after shelling?

medium

A. 90 mm

B. 100 mm

C. 95 mm

D. 85 mm

Solution

1. Step 1: Understand shelling effect on height

   Shell removes 5mm thickness from all internal faces except the removed top face, so height reduces by wall thickness at bottom only.

2. Step 2: Calculate hollow height

   Original height 100mm minus 5mm wall thickness at bottom = 95mm hollow height.

3. Final Answer:

   95 mm -> Option C

4. Quick Check:

   Height after shell = 100 - 5 = 95 mm [OK]

Hint: Subtract wall thickness only where faces remain [OK]

Common Mistakes:

• Subtracting thickness twice
• Ignoring removed face effect
• Assuming hollow height equals original height

4.

You applied a Shell feature with 3mm thickness but the shell did not create a hollow part. What is the most likely reason?

medium

A. The part is already hollow

B. You forgot to select faces to remove

C. The material color is not set

D. The wall thickness is larger than half the smallest part dimension

Solution

1. Step 1: Identify shell failure cause

   If wall thickness is too large (more than half the smallest dimension), shelling cannot hollow the part.

2. Step 2: Check other options

   Not selecting faces or material color does not prevent shelling; part being hollow is unrelated to failure.

3. Final Answer:

   The wall thickness is larger than half the smallest part dimension -> Option D

4. Quick Check:

   Thickness > half dimension causes shell failure [OK]

Hint: Wall thickness must be less than half smallest dimension [OK]

Common Mistakes:

• Ignoring size limits for thickness
• Assuming color affects shell
• Thinking shell needs face removal always

5.

You have a solid cylinder 50mm diameter and 100mm height. You want to create a hollow cylinder with 4mm wall thickness and an open top using the Shell feature. Which steps should you follow?

hard

A. Apply Shell with 4mm thickness without removing any face

B. Apply Shell with 4mm thickness, then select the top face to remove

C. Create a new sketch of a hollow cylinder and extrude it

D. Use Fillet tool to hollow the cylinder

Solution

1. Step 1: Set wall thickness in Shell feature

   Enter 4mm as wall thickness in the Shell property manager.

2. Step 2: Remove the top face to create an opening

   Select the top face of the cylinder to remove it, making the cylinder hollow with an open top.

3. Final Answer:

   Apply Shell with 4mm thickness, then select the top face to remove -> Option B

4. Quick Check:

   Shell + remove top face = hollow open cylinder [OK]

Hint: Remove faces to create openings after setting thickness [OK]

Common Mistakes:

• Not removing the top face for opening
• Using sketches instead of Shell
• Trying to hollow with Fillet tool