thank you for these free and huge software Libre Cad .. i need to delete small part of the circuit how i can do that you can see that in the picture i draw CNC Drill holder but i cant make it 100% becuose of that small part of circuit you can see what i mean in the second picture for the draw with Google sketchup sorry for my English I am Arabic native
Use the divide command in the modify tab. Specify entity to cut: select the circle above the upper horizontal line. Specify cutting point: select the joint of the circle and the upper horizontal line with snap to endpoint or snap to intersection activated.
Then again divide: Specify entity to cut: select the circle below the lower horizontal line. Specify cutting point: select the joint of the circle and the lower horizontal line.
Now you can delete the circle part between the two horizontal lines.