Test 1 Mechanical: SolidWorks CAD – Beginner Level

Assessment of fundamental skills in Computer-Aided Design (CAD) through 3D part modeling and mechanical assembly under SolidWorks.

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Objective

This test evaluates our fundamental skills in CAD using SolidWorks software. The objective is to create, from dimensioned sketches, a set of functional 3D parts respecting material, mass and geometry constraints, then perform a functional mechanical assembly with center of gravity calculation.

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Modeled parts

We designed four individual parts from 2D plans, using the basic tools of the software.

Methodology used

• 2D Sketches: rectangles, circles, polygons, construction lines
• 3D Features:
  • Boss/Base by extrusion
  • Material removal by extrusion
  • Fillets (radii)
  • Symmetry
• Sketch constraints: horizontal, vertical, tangent, coincident, symmetric
• Unit system: MMGS (mm, gram, second)
• Decimals: 2 digits after the decimal point
• Holes: all through unless otherwise indicated

Part details

Part	Material	Density (g/mm³)	Obtained mass
Part 1	AISI 1020 Steel	0.0079	2850.16 g
Part 2	Aluminum 1060	0.0027	279.77 g
Part 3	AISI 1020 Steel	0.0079	1633.25 g
Part 4	Aluminum 1060	0.0027	297.29 g

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Mechanical gripper assembly

The mechanical gripper assembly was performed under SolidWorks from the components provided in the .zip file. The objective was to correctly assemble all parts while respecting the degrees of freedom necessary for the gripper's operation, particularly its opening and closing via the cylinder action.

Used parts

• Cylinder body
• Cylinder rod
• Cylinder end
• Links (left and right)
• Link pins
• Jaw supports (left and right)
• Jaws (left and right)
• Circlips (locking elements)
• CHC screws M5x25
• Jaw support pin

Main assembly steps

1. Base fixation

   • The sub-assembly containing the cylinder (body + rod + end) was inserted and fixed as reference (immobile component).

2. Link assembly

   • The two links were inserted and constrained with:
     • Concentric constraint: alignment of rotation axes with cylinder holes
     • Symmetry constraint: identical and opposite movement on both sides via the top plane

3. Addition of supports and jaws

   • Each jaw support was assembled with its corresponding link:
     • Concentric: between the support hole and the link
     • Coincident: to fix the lateral position
   • The jaws were fixed on the supports with the same types of constraints.

4. Insertion of link pins

   • The pins were used instead of screws, with the following constraints:
     • Concentric: between the pin and the through holes
     • Coincident: between the pin head and the contact surface

5. Placement of circlips

   • The circlips were inserted to mechanically lock the pins, without adding unnecessary overconstraints.

Used constraints

Constraint type	Use
Concentric	Axis alignment (holes and pins)
Coincident	Contact between flat faces
Symmetry	Movement synchronization

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Center of gravity analysis

The center of gravity analysis allows better understanding of the gripper's balancing in different operating positions. It was performed under SolidWorks after finalizing the assembly.

a) Minimum position of the cylinder rod

In this position, the cylinder rod is fully retracted into the body, corresponding to the closed gripper state.

Center of gravity coordinates (in mm):

• X = -29.15
• Y = 0.16
• Z = 19.93

b) Maximum position of the cylinder rod

The rod is fully extended, corresponding to the open gripper state.

Center of gravity coordinates (in mm):

• X = -25.78
• Y = 0.06
• Z = 19.93

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Problems encountered and solutions

Problem	Probable cause	Applied solution
Overconstraints of certain parts	Excessive or contradictory constraints	Removal of redundant constraints and verification of degrees of freedom
Error when applying symmetry	Poor selection of faces or reference plane	Correct reapplication with selection of both faces and the top plane
Blocking of gripper movement	Too many fixed parts or locked constraints	Application of only essential constraints (coincident and concentric)
Circlips blocking movement	Too many constraints applied to circlips	Addition of only one constraint (e.g. concentric) to avoid blocking

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Graphical resources and SolidWorks files

Part 1

2D View	3D View

Part 2

2D View	3D View

Part 3

2D View	3D View

Part 4

2D View	3D View

Final assembly

SolidWorks 2025 source files

• Download source files

These visual elements facilitate the technical reading of the project and serve as proof of modeling within the TRC2K25 framework.

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Conclusion

This test allowed us to validate our ability to:

• Model precise mechanical parts
• Apply functional materials and constraints
• Perform realistic assembly under constraints
• Evaluate properties such as mass and center of gravity

This project constitutes a solid foundation for more complex mechanical designs within the TRC2K25 framework.