I recommend you draw a poly of the plan outline (with the side ridges), extrude it and rotate the top surface to make the slope.
Then triangulate it and use the boolean plugin to cut out the space for the blade and the conical hole. Before using the boolean plugin, ensure that the surfaces are all facing outwards (press 'n' to check normals).
Use a cylinder with one end reduced to make the cone that cuts out the 'pencil tip' shape.
Andy
|