Wire EDM. How it’s done?
Wire EDM is a stress free machining technique that works by submerging a workpiece and a cutting wire into de-ionized water. An electrical current is then sent through the cutting wire to create an electrical discharge, or spark, between the wire and the workpiece. This discharge or sparking, removes material from the workpiece and the wire to produce the desired shape in the workpiece. EDM machining can produce complex, high quality, precision parts out of even the toughest material. As long as it can conduct electricity, it can be cut using EDM. The way wire EDM works makes it a perfect candidate for burr free parts.
Wire EDM. What we can do for you?
At Grace, we have been cutting parts with wire EDM for more then 20 years. We can combine our other capabilities with wire EDM to produce highly complex parts that would otherwise be very difficult and expensive to produce. With our machines we can routinely hold a +/-.001 tolerance, regardless of quantity. If necessary we can improve the tolerance to meet your needs. We can handle high production volumes with quick turnaround time. Recently, we installed two brand new wire EDM machines in our facility bringing our machine count to six and increasing our production rate.
Photo Chemical Machining
What is Photo Chemical Machining?
Photo Chemical Machining (PCM) is known by many names such as: Photo Chemical Milling, Photo Etching, Photo Chemical Etching, Photo Fabrication, Chemical Etching, Photo Milling, Acid Etching, or Chemical Blanking. Call it what you will, the results are the same: superior quality, extremely precise, highly repeatable, finely detailed, tight tolerance, economical parts, with no burr and no added stresses or strains. This process can offer economical alternatives to stamping, punching, laser or water jet cutting, or wire electrical discharge machining (EDM) for thin metal precision parts. Most materials experience no change to mechanical properties through photo chemical machining. Typical metals to be etched include brass, copper, nickel, steel, and stainless steel.
The tooling for photo chemical etching is inexpensive and quickly produced. Unlike “hard” tools, such as stamping and punching dies, phototools are exposed only to light and therefore do not suffer the wear typically associated with tooling. This makes the process useful for prototyping and allows for easy changes in mass production. Phototools allow complex features to be machined at the same cost as a single simple hole. If the metal parts are designed to be formed into shapes after the etch process, bend lines can be incorporated into the phototool. The resulting “half-etched” areas are produced on one side of the part providing precise points for forming.
Photo Chemical Machining Process
Photo chemical machining is the fabrication of sheet metal components using acid to chemically remove the unwanted material from the sheet leaving you with exceptional parts. The processing begins with a supplied drawing or you can allow our engineers to tackle the task of creating the drawings for you. This can be done either through a collaborative effort with you or your designers or we can reverse engineer them for you. Once the drawing has been created, a laser plotted phototool is generated. The phototool consists of two sheets of optically clear and dimensionally stable film which shows negative images of the parts (meaning the area that will become the parts is clear and all of the areas to be etched are black). The two sheets are aligned to form the top and bottom halves of the tool.
While the phototool is being created the metal sheets are cut to size, cleaned and then laminated on both sides with a UV-sensitive photo resist. The coated metal is placed between the two sheets of the phototool and a vacuum is drawn to ensure complete contact between the phototool and the metal sheet. The resist is then exposed to a UV light which allows the areas of resist that are in the clear sections of the film to be hardened. After exposure, the resist is developed, washing away the unexposed resist and leaving the areas to be etched unprotected. Then the exposed and developed sheet enters the etcher. The etcher is a multi-chambered machine which has a conveyor to move the metal and arrays of spray nozzles above and below the metal. The etchant is typically an aqueous solution of acid (ferric chloride) that is heated and sprayed under pressure on both sides of the sheet. The etchant reacts with the unprotected metal essentially corroding it away. After neutralizing and rinsing, the parts are checked for dimensional quality, the remaining resist is stripped and the sheet of finished parts is cleaned and dried.
Photo chemical machining coupled with our other available processes such as: laser cutting, wire edm, stamping, forming, and finishing operations give Grace Manufacturing a distinct advantage. That advantage means that you will get the desired part, with the desired finish, within the desired tolerance, quickly and accurately every time.
Grace Manufacturing has five Amada high-powered CO2 laser cutting work stations; four of which are unique in that they utilize a rigid cast machine base and fixed optics for maximum cut accuracy.
These machines can cut a wide variety of materials including all grades of stainless steels, carbon steels, Kovar and titanium up to .5″ thick (depended on metal type).
Power Output Capability
2000 Watts, Continuous Wave (CW), Gated Pulse (square wave), Super Pulse ( 2.5 X CW power) and Hyper Pulse ( Amada’s proprietary pulse shapes for optimal metal cutting).
The versatility of these power outputs and pulse rates of up to 5,000 Hz allow us to produce accurate cuts and clean edges while minimizing any undesirable heat effects.
Specified positioning accuracies of +/- 0.0002″ in 20″ of travel and a repeatability of 0.000079″ allow us to produce laser cut parts with a feature positional and edge to edge accuracies of up to +/- .001″ or better depending on the particular material’s properties.
A Unique Grace Advantage- Combined Laser Cutting, Chemical Machining and EDM
At Grace Manufacturing we specialize in combining advanced technologies; laser cutting, photo- chemical machining and wire EDM (Electrical Discharge Machining) to produce parts that have accurately located, stepped channels, pocket and edge features. Complex parts can be produced by using unique combinations of the these technologies without the need for expensive hard tooling.
A list of typical parts produced at Grace Manufacturing include; encoder discs, lead frames, shims and spacers, EMI shields, valve plates, spring contacts and reed valves. There are numerous other applications beyond these.
There are limitations, such as size of openings, tolerances attainable at various thicknesses, etc… Contact Grace Manufacturing with any questions or concerns and let us submit a quote for your next manufacturing need.
High Precision Plastic Parts
Grace Manufacturing continues to expand its injection molding capabilities with the recent acquisition of 2 additional machines. With 6 machines possessing 30 to 190 ton press ratings and over 70 years of combined injection molding experience, we are capable of producing plastic parts of complex geometries utilizing a broad spectrum of engineering resins, including clear polycarbonate for medical applications.
Our production team encompasses in-house engineering support, quality control experts and highly experienced operators ensuring strict adherence to customer specifications. Whether your needs are for individually molded parts or a finished product that includes plastic components, our injection and insert molding processes will provide you with a high quality part manufactured in an environmentally controlled room and under our ISO 13485 Medical Device Quality Management System.
If you have any questions or would like to discuss how Grace Manufacturing can become a part in the fulfillment of your production needs, please contact us to speak directly to the appropriate engineer or production specialist.
Finish – Tumble, Timesave, Scubber
Plating – Gold, Nickel, Copper