This month’s Rob Report is guest-written by Robert’s father, Abraham Savitzky, founder and Chairman of RS Precision. Abe is one of the true pioneers of EDM, having purchased his first Elox sinker in 1960.
Today’s markets for high performance instruments and devices require manufacturing innovations to achieve both performance superiority and cost advantages. When used knowledgeably, EDM can play a key role in producing products with a clear competitive edge.
Design freedom. Unlike conventional machining, EDM allows design engineers to have almost complete freedom of shapes and configurations for the component’s features. This can be used to gain performance advantages, as well as to differentiate their products from their competition.
Consistency and Repeatability. Highly irregular shapes can be produced very accurately by EDM. Because fresh electrodes are used for every piece, EDM eliminates dimensional variations experienced in conventional machining due to deflection of the tool and/or part, or changes in surface finish due to worn or chipped tool edges.
Material-friendly. EDM is often used to machine the most difficult-to-cut materials—any material, in fact, that is electrically conductive. Cutting internal threads and fabricating intricate or complex shapes into extremely hard materials are routinely done. With no physical contact between the electrode and work piece, EDM is used to cut intricate configurations in parts too small or fragile to clamp firmly enough for conventional machining.
Cost effective. The cost of EDM is dramatically reduced when multiple parts are processed simultaneously. EDM also affords significant savings in cutting tool and deburring costs. Moreover, micro-machined parts and features too difficult to do conventionally can often be produced easily and cost effectively by EDM.
EDM is particularly suitable for numerous industry applications, including:
Medical. EDM is often used to produce parts needed for miniature flexible endoscopes, medical instruments and other devices regularly needed for minimally invasive and orthopedic surgery.
Aerospace. Small, precision, performance-critical parts and features in difficult-to-machine alloys are commonly produced by EDM. Cross-connecting parallel bores and holes deep within hydraulic manifolds can be readily created by EDM without drilling from the outside.
Optical. High performance optical assemblies require very precise geometric relationships and tight tolerances. Achieving this in miniature and micro parts is challenging, but can often be done most cost effectively by EDM.
Valves and Sensors. Very small, consistent and burr-free orifices and metering openings for valves and sensors are routinely produced by EDM, as well as delicate flexures and diaphragms.
As with any manufacturing process there are some important factors that must be carefully considered, one being that EDM electrodes wear out much faster than conventional cutting tools. Superior electrode producing methods can overcome much of this disadvantage enabling the supplier to provide customers with greater part-to-part consistency. Finally, because EDM cutting rates are definitely not as fast as conventional machining, it is best to leave the bulk material removal to conventional machining, and reserve those machining operations that require “finesse” to EDM.
So can EDM provide advantages for your precision parts? Probably. Just be sure you’re working with a supplier that has extensive EDM capabilities, and the electrode and fixturing expertise so very integral to the EDM process. A close partnering between customer design engineers and the right EDM supplier will yield insights into functional requirements and production constraints that should guide the decisions of how best to produce the part. Together, you’ll create the optimal solution—being assured your finished part is of superior value.