Textbooks portray design and manufacture as a linear process, but in reality it’s more iterative. Features, tolerances and materials specified by Engineering Challenge Manufacturing, who respond by requesting design changes. Reasoned discussion usually leads to better choices, but ultimately the product must function the way the designer wants. In such situations the only solution may be a rushed search for outside EDM machining services.
This reactive approach is the wrong way to go. Rather than having manufacturing processes compromise functionality, plan on using EDM machining from the outset. This way the design intent is realized while saving both time and money.
Two types of EDM
EDM machining has come a long way since it was known as spark erosion. Today it exists as both wire and die sinking EDM, although the fundamental principles are unchanged: voltage between tool and electrically conductive workpiece creates a spark. Where it strikes the work piece, this melts and ejects particles of material, some of which are carried away by a fluid before they can become reattached.
Similar to a carpenter’s fretsaw in that it has a very small diameter, wire edm can produce intricate forms in hard, electrically conductive material. The wire itself is fed past the work piece, being moved by an X-Y motion system. Wire EDM machines add two additional axes enabling cutting of angled surfaces.
Die sinking EDM employs an electrode, usually graphite, shaped in a mirror image of the required form. Positioned above the work piece, it inches down as material is removed, maintaining a constant gap. A few EDM machining shops specialize in one or the other but these days most like to provide the full range of EDM services.
Greater Design Freedom
Milling cutters can’t produce right-angled corners in recessed pockets. Grinding wheels have diameter and speed requirements making them difficult to use in tight spaces. Narrow slots, high depth-to-diameter ratio holes and thin-walled sections are all hard to produce with conventional cutting processes. Limitations like these constrain the product or tool designer’s freedom to create the shapes needed.
EDM changes that because it can be used create complex 2D and 3D forms in any conductive material. Here are six ways EDM gives the designer more freedom:
- Die sinking EDM can produce pockets with sharp corners and complex forms. This allows tighter fits around square or rectangular inserts.
- Thin walls are possible because cutting forces are virtually zero. One benefit is to put cooling channels close to hot surfaces.
- Higher aspect ratio (deeper and narrower,) holes and pockets are possible.
- EDM wire cutting allows unlimited freedom to cut intricate 2D shapes. On a 4 axis machine it’s possible to produce 3D features like the tapers and draft angles needed in extrusion and casting dies.
- EDM Machining can handle hard materials that must otherwise be ground. Any form that can be machined into the electrode will be reproduced, even with complex curves, and material hardness has no effect on speed or precision.
- The ability to make complex 3D forms means the designer can create a one-piece form tool or die. The alternative is to use multiple pieces or inserts that add complexity, variability and cost.
Consider EDM services early
By removing the constraints imposed by conventional metal-cutting, EDM machining gives designers of products and product tooling greater freedom to achieve their design goals. Pockets can have sharp corners for superior fit, thinner walls enable faster cooling, holes and pockets can go deeper and intricate shapes can be cut.
Too often though, EDM is seen as a last resort, a process to use when conventional processes don’t work. That leads to a panicked search for EDM services and can force design compromises. Include EDM machining as one of the possible manufacturing processes during the design stage, and save time and money while achieved the desired levels of functionality.
About Micropulse West
Since 1994, Micropulse West has been proudly offering Precision Manufacturing Services such as EDM, CNC and Manual Machining to companies within highly regulated industries like Aerospace/Defense, Energy, Medical, High Tech as well as the Automotive and Firearms Industry. Our skilled and experienced machinists use the latest and most accurate Precision Machining technologies in order to deliver the highest quality precision machined parts. From small prototyping projects to high volume machining projects, Micropulse West is the Precision Machine Shop you can trust.
If you would like to learn more about what makes Micropulse West different and how we can help with your precision machining needs, call 1- 480-966-2300.