The sharpening of diamond tools with small apex angles by low energy (1.0 keV) ion beam faces great challenges because of facet formation at the cutting edge of the tools. Adding to the problem is the formation of ripple, also appearing at the cutting edge of the tools that occurs when the ion beam bombardment is done at some off-normal angle of incidence. In this work, the authors investigated the dependence of the facet angles on the ion beam energy. They also studied the phenomenon of ripple formation as influenced by ion dose, ion beam energy, and ion incidence angles. Based on the experimental results they then developed a method for sharpening the tool with 45 degrees apex without facet formation. They also studied ripple formation using 1.0 keV Ar+ ion beam at a tilt angle beta of 30 degrees. The work also used simulations to predict the changes in the profile of diamond tools during ion beam machining at a fixed tilt angle beta. They found that simulation results on the profile of the diamond knife matched quite well with the experimental results. They conclude that it is possible to make sharp diamond knife with an apex angle of 45 degrees and that sharpening time can be predicted applying simulations.