Component degrees of freedom in Solidworks - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does 'degrees of freedom' mean in the context of a component in SolidWorks?

Degrees of freedom refer to the number of independent ways a component can move or rotate in 3D space before it is fully constrained.

beginner

How many total degrees of freedom does a free component have in 3D space?

A free component in 3D space has 6 degrees of freedom: 3 translations (X, Y, Z) and 3 rotations (around X, Y, Z axes).

intermediate

What happens to a component's degrees of freedom when you add a mate in SolidWorks?

Adding a mate reduces the component's degrees of freedom by restricting certain movements or rotations, helping to fix its position relative to other components.

beginner

Name the types of movements that count as degrees of freedom for a component.

The types are: translation along X, Y, Z axes and rotation around X, Y, Z axes.

intermediate

Why is it important to fully constrain components in an assembly?

Fully constraining components removes all degrees of freedom, preventing unexpected movement and ensuring the assembly behaves as designed.

How many degrees of freedom does a component have before any mates are applied?

A 6

B 3

C 9

D 12

A free component in 3D space has 6 degrees of freedom: 3 translations and 3 rotations.

Which of the following is NOT a degree of freedom for a component?

A Scaling in size

B Translation along Y axis

C Rotation around X axis

D Rotation around Z axis

Scaling is not a degree of freedom; degrees of freedom refer only to movement and rotation.

What effect does adding a mate have on a component's degrees of freedom?

A No effect

B Increases degrees of freedom

C Decreases degrees of freedom

D Resets degrees of freedom

Adding mates restricts movement, reducing degrees of freedom.

Which movement is NOT restricted by a coincident mate?

A Rotation around an axis perpendicular to the mate plane

B Rotation around the mate axis

C Translation perpendicular to the mate plane

D Translation along the mate plane

A coincident mate restricts movement perpendicular to the plane but allows translation along the plane.

Why should you fully constrain components in an assembly?

A To allow free movement

B To prevent unexpected movement

C To increase degrees of freedom

D To make the assembly heavier

Fully constraining components prevents unexpected movement and ensures correct assembly behavior.

Explain what degrees of freedom are for a component in SolidWorks and why they matter.

Think about how a part can move or rotate before it is fixed.

Describe how mates affect the degrees of freedom of a component in an assembly.

Consider how adding constraints changes movement.

Practice

1. In SolidWorks, how many degrees of freedom does a new component have before applying any mates?

easy

A. 6 degrees of freedom

B. 3 degrees of freedom

C. 0 degrees of freedom

D. 9 degrees of freedom

Solution

1. Step 1: Understand degrees of freedom in 3D space

   A component in 3D space can move along 3 axes and rotate about 3 axes, totaling 6 degrees of freedom.

2. Step 2: Recall initial state of a new component

   Before any mates are applied, the component is free to move and rotate in all 6 ways.

3. Final Answer:

   6 degrees of freedom -> Option A

4. Quick Check:

   Initial freedom = 6 [OK]

Hint: Remember 3 translations + 3 rotations = 6 freedoms [OK]

Common Mistakes:

• Confusing degrees of freedom with number of mates
• Thinking zero means free movement
• Assuming 3D space has only 3 freedoms

2. Which of the following is the correct way to describe a component with zero degrees of freedom in SolidWorks?

easy

A. The component is fully fixed and cannot move or rotate

B. The component can move freely in all directions

C. The component can only rotate but not translate

D. The component has unlimited degrees of freedom

Solution

1. Step 1: Define zero degrees of freedom

   Zero degrees of freedom means no movement or rotation is possible.

2. Step 2: Interpret what fully fixed means

   A fully fixed component cannot translate or rotate in any direction.

3. Final Answer:

   The component is fully fixed and cannot move or rotate -> Option A

4. Quick Check:

   Zero freedom = fully fixed [OK]

Hint: Zero freedom means no movement at all [OK]

Common Mistakes:

• Thinking zero freedom means free movement
• Confusing rotation freedom with translation freedom
• Assuming partial movement is allowed

3. If a component initially has 6 degrees of freedom and you apply 3 mates that each restrict one degree of freedom, how many degrees of freedom remain?

medium

A. 9 degrees of freedom

B. 3 degrees of freedom

C. 0 degrees of freedom

D. 6 degrees of freedom

Solution

1. Step 1: Start with initial degrees of freedom

   The component starts with 6 degrees of freedom.

2. Step 2: Subtract degrees restricted by mates

   Each mate restricts one degree, so 3 mates restrict 3 freedoms.

3. Step 3: Calculate remaining degrees of freedom

   6 - 3 = 3 degrees of freedom remain.

4. Final Answer:

   3 degrees of freedom -> Option B

5. Quick Check:

   6 - 3 = 3 [OK]

Hint: Subtract mates from 6 freedoms to find remaining [OK]

Common Mistakes:

• Adding mates instead of subtracting
• Assuming each mate restricts multiple freedoms
• Confusing total freedoms with mates count

4. You applied 6 mates to a component, but it still moves. What is the most likely reason?

medium

A. The component has infinite degrees of freedom

B. You need to apply more mates to fix the component

C. Some mates are redundant and do not reduce degrees of freedom

D. SolidWorks does not support fixing components

Solution

1. Step 1: Understand mate redundancy

   Some mates may overlap in restricting the same freedom, causing redundancy.

2. Step 2: Recognize effect of redundant mates

   Redundant mates do not reduce additional degrees of freedom, so movement remains.

3. Final Answer:

   Some mates are redundant and do not reduce degrees of freedom -> Option C

4. Quick Check:

   Redundant mates don't fix movement [OK]

Hint: Check for redundant mates if component still moves [OK]

Common Mistakes:

• Assuming more mates always fix movement
• Ignoring mate redundancy
• Believing SolidWorks cannot fix components

5. You have a component with 2 degrees of freedom left. You want to fully fix it by applying mates. Which combination of mates will correctly reduce the remaining freedoms?

hard

A. Apply 3 mates that restrict only one degree of freedom each

B. Apply 1 mate that restricts 2 degrees of freedom simultaneously

C. Apply 2 mates that restrict the same degree of freedom twice

D. Apply 2 mates that each restrict one unique degree of freedom

Solution

1. Step 1: Identify remaining freedoms

   The component has 2 freedoms left to restrict.

2. Step 2: Choose mates that restrict unique freedoms

   Each mate must restrict a different freedom to reduce total freedoms correctly.

3. Step 3: Avoid redundant mates

   Applying mates that restrict the same freedom twice does not reduce freedoms further.

4. Final Answer:

   Apply 2 mates that each restrict one unique degree of freedom -> Option D

5. Quick Check:

   Unique mates reduce freedoms correctly [OK]

Hint: Use mates targeting different freedoms to fully fix [OK]

Common Mistakes:

• Applying redundant mates on same freedom
• Assuming one mate can restrict multiple freedoms
• Applying more mates than needed without effect