Understanding FreeCAD Lesson 2 Part Design Master Sketch Parametric multi-body project for Beginners

Introduction

This tutorial will guide you through the master sketch workflow in FreeCAD using the Part Design workbench. We will create a simple multi-body project, specifically a spool holder, using a master sketch as a reference template. This method allows you to maintain parametric relationships between parts, ensuring any changes to the master sketch automatically update all related components.

Step 1: Create the Master Sketch

1. Open FreeCAD and Select Sketcher Workbench

   • Launch FreeCAD and switch to the Sketcher workbench.

2. Create a New Sketch

   • Create a new sketch on the ZX plane.
   • This sketch will serve as the master sketch for the spool holder.

3. Draw the Spool Profile

   • Create a circle representing the spool.
   • Set the diameter to 200 mm.
   • Add dimensions to keep track of sizes.

4. Add Attachment Features

   • Draw an inner circle (50 mm) for the bar that will hold the spool.
   • Create another circle (80 mm) for the stand support.

5. Create the Stand Geometry

   • Draw lines to represent the triangular support pieces.
   • Ensure the lines are tangent to the circles where necessary.
   • Add horizontal constraints to keep elements aligned.

6. Finalize the Master Sketch

   • Add any additional elements, such as blocks for mechanisms, if desired.
   • Use constraints to fully define the geometry, ensuring stability for future adjustments.
   • Save and close the master sketch.

Step 2: Set Up the Bodies

1. Switch to Part Design Workbench

   • Transition to the Part Design workbench to create individual bodies.

2. Create a New Body for the Spool

   • Create a new body and add a new sketch on the same ZX plane.
   • Clone the master sketch into this body using the Draft workbench.

3. Link the Master Sketch

   • Drag the cloned sketch into the new body.
   • Use the edge link to external geometry tool to reference the master sketch features.

4. Pad the Sketch

   • Select the sketch and pad it to create the spool body, choosing the desired thickness (e.g., 50 mm).

Step 3: Create the Support Body

1. Create a New Body for the Support

   • Create another body for the support structure.
   • Clone the master sketch again into this body.

2. Import Geometry

   • Reference the master sketch geometry as before and create the necessary lines and arcs to define the support shape.

3. Pad the Support Sketch

   • Pad the support sketch to the desired height (e.g., 20 mm).

Step 4: Create the Base Body

1. Create a New Base Body

   • Create a third body for the base of the spool holder.
   • Clone the master sketch into this body.

2. Reference Geometry

   • Use the edge link to include relevant features from the master sketch in your base sketch.

3. Pad the Base Sketch

   • Pad the base sketch to create the base component, adjusting dimensions as necessary.

Step 5: Assemble the Components

1. Switch to Assembly Workbench

   • Transition to the assembly workbench (e.g., A2 Plus) to begin assembling the parts.

2. Import the Bodies

   • Import the spool, support, and base bodies into the assembly environment.

3. Position the Components

   • Use constraints to align and position the parts relative to one another, ensuring they fit together correctly.

4. Final Adjustments

   • Make necessary adjustments to spacing, ensuring all components are properly aligned.

Conclusion

In this tutorial, you have learned how to create a parametric multi-body project in FreeCAD using a master sketch. By following the master sketch workflow, you can easily modify the design and see changes reflected in all related components. This method is essential for efficient and organized CAD modeling, making it easier to assemble and modify complex designs. Next, consider exploring more advanced assembly techniques or additional FreeCAD features to enhance your projects further.