How to Cut a FreeCAD Object in Half and Make It Longer

If you need to make an existing FreeCAD solid longer without rebuilding it from scratch, you can cut it into two pieces, move one half to create a gap, fill the gap with a new solid, and then join everything back together.

1. Part Design → Create Datum Plane

   • Position the Datum Plane where you want to cut.

2. Switch to the Part workbench.

3. Select the solid first.

   • Hold Ctrl.

   • Select the Datum Plane second.

   • The selection order matters.

4. Part → Split → Slice apart

   • You should now have two separate solid pieces.

5. Move one half

   • Change its Placement → Position by the desired distance.

6. Fill the gap

   • Create a new solid with the same cross-section and the required length.

7. Join everything

   • Select both halves and the new connecting solid.

   • Use Part → Boolean → Union.

Key point

Solid first → Datum Plane second → Slice apart.

The Datum Plane is the cutting tool; it is not the object being sliced.