Mindwired

If you want to remove a rectangular section from an existing solid in FreeCAD, you can use a Part Box as the cutting object and perform a Boolean Cut. This works similarly to using a cube to make a hole, except the removed section can extend through the entire object. Steps Create a Part Box Switch to the Part workbench. Create a Box . Position and size it where you want the material removed. Make the Box intersect the solid The Box must physically overlap the original solid. It can extend beyond the solid if you want to cut all the way through. Select the objects in the correct order Select the original solid first . Hold Ctrl and select the Box second . Perform the Boolean Cut Go to Part → Boolean → Cut . The result is: Original solid − Box = Cut solid The Box acts as the cutting tool and is removed from the result. Important The selection order matters: Solid first → Box second → Boolean Cut This is different from Boolean Union , where selection order does not matter. This method...

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. Part Design → Create Datum Plane Position the Datum Plane where you want to cut. Switch to the Part workbench. Select the solid first. Hold Ctrl . Select the Datum Plane second . The selection order matters. Part → Split → Slice apart You should now have two separate solid pieces. Move one half Change its Placement → Position by the desired distance. Fill the gap Create a new solid with the same cross-section and the required length. 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.