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Several series of experiments were conducted to compare the performance of selected sets of subtractive and additive machine tools for meso-micro machining. Under the MicroCutting Project, meso-micro machining of a reference part was conducted to compare the performance of several machine tools. A prototype flexure of the microspline of an asteroid gripper under development at NASA/JPL was selected as the reference part for the project. Several academic, research institutes, and industrial firms were among the collaborators participating in the project. Both subtractive and additive machine tools were used, including abrasive waterjets, CNC milling, lasers, 3D printing, and laser powder bed fusion. Materials included aluminum, stainless steel, and nonmetal resins. Each collaborator produced the reference part in its facility using materials most suitable for their tools. The finished parts were inspected qualitatively and quantitatively at OMAX Corporation. The performance of the participating machine tools was then compared based on the results of the inspection. Test results show that the two top performers for this test part are the CNC precision milling and micro abrasive waterjet. For machining a single flexure, the CNC precision milling had a slight edge over the micro abrasive waterjet machining in terms of part accuracy and edge quality. The advantages disappear or the trend even reverses when stack machining with taper compensation is adopted for the micro abrasive waterjet.

Abrasive waterjets have recently become a popular tool for mechanical machining. With its great advantages of geometric and material flexibility and its ability to cut hard-to-machine material, the technology is quickly spreading throughout many industries. With this process, near net-shape production becomes feasible, while significantly reducing the time necessary for secondary operations such as programming, clamping, or tool changing. This allows a significant optimization of the overall manufacturing process chain. In this paper, different approaches to increase the economic and technical efficiency of cutting with abrasive waterjets are analyzed. Experimental analysis of the speed of abrasive particles show that the kinetic power of the particles mainly depends on the hydraulic power of the waterjet. Merely increasing the pressure of the jet did not yield any improvement in its acceleration capability. To obtain the most effective cutting performance, a high level of hydraulic power through large nozzles should therefore be utilized. Additionally, recent advancements in cutting path control software have proven to significantly decreasing the total “time to product” and to increase the precision of the part. Those improvements in both software control and cutting power enable abrasive waterjets to become an integral part of many industrial manufacturing processes. This will widen the scope of possible applications of this innovative and promising technology.