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10 Tips for Better Wire EDM Results
Just because wire EDM is computer-controlled does not automatically mean you get the best results by pushing buttons. The process encompasses a lot and needs careful consideration from setting up the machine and preparing the workpiece to carefully programming and cutting the part. Even as an experienced wire EDM engineer, there are some tips and tricks you should be aware of before carrying out the operation. This will ensure accurate results and boost overall productivity.
When cutting parts with wire EDM, it is important to consider the workpiece material to optimize the process. The material will determine the type of wire electrode, pulse duration, and pulse interval. This article will go over 10 tips you can employ for a better wire EDM experience. Read on to find out more
Wire Electrical Discharge Machining Tips and Tricks
Let’s cover 10 essential tips you can use to get better wire EDM results.
- Adequate Preparation
It is important to prepare and clean the workpiece and environment. The presence of impurities, dirt, rust, and other contaminants can affect the flow of electricity and cut quality. You do this using water or alkaline-based solvent soaked in a clean rag. Additionally, consider grinding and rolling the metal surface to remove burrs and protrusions. These burrs when not removed can obstruct and break the wire electrode.
Furthermore, you should clean the environment before carrying out the EDM process. Ensure that the air and humidity levels are regulated and the power supply is stable. Wearing appropriate PPE is essential to prevent work-related hazards.
- Calibration and Maintenance
It is recommended to calibrate your machine regularly. You can do this during routine maintenance or before each use. Check the travel distance of the machining along the X, Y, and Z axes using a micrometer or dial gauge. Ensure that they are up to standard and adjust as required.
Furthermore, you have to proactively inspect the components of the machine to ensure they are in good condition. Keep the software up to date and clean the wire electrodes for proper electrical discharge. Furthermore, you should lubricate movable parts to reduce sudden breakdowns and unexpected delays.
- Material Selection
Material selection is a critical step in wire EDM cutting. The result you get depends on the material you are using. Not all engineering metals can be safely cut with wire EDM. You need to consider the chemical composition, electrical conductivity, hardness, and thermal conductivity.
Metals with a low carbon content are generally preferred because they are not prone to heat damage. Furthermore, those that conduct electricity and heat produce better results. Additionally, go for harder metals if possible because softer ones may be difficult to cut.
- Proper Wire Selection
The type and size of the wire you use will also determine the success of the cutting operation. There are different wire materials including brass, zinc-coated, copper, molybdenum, and tungsten. Brass is the most common because its high conductivity increases productivity. Furthermore, the wire size is usually between 0.10 to 0.30mm. Note that the smaller the wire, the lower the cutting speed and power required.
You should keep in mind some important factors while selecting the type of wire. Some of these include the workpiece material and thickness, desired surface finish, cost, volume of production, and compatibility with the machine itself.
- Wire Tension and Guidance
The tension in the wire determines the accuracy of the cut it makes. This is because sudden changes in tension increase the risk of vibration while it is moving. Though the machine comes with a control system, you should always monitor and adjust wire tension in real time if there are deviations. This gives a better cutting experience and ensures that the final parts are of high quality.
In addition to maintaining the wire tension, adequate guidance also prevents deflection and vibrations. The guides are made with materials that are stronger than the wire. You will find them either in diamond or sapphire located in the lower or upper machine heads. Guides properly align the wire electrode and secured it as it cuts through a workpiece. This action helps to achieve a stable cutting action.
- Maintain Proper Dielectric Current
The most common dielectric fluid used in wire EDM cut is deionized water. Deionized water is a semiconductor that maintains the gap between the workpiece and the wire electrode. It controls electric discharge and serves as a cooling system to prevent overheating. Additionally, deionized water flushes away metal particles providing a clean environment.
You must maintain proper dielectric current to get optimal results. Always submerge the wire and part in clean and particle-free deionized water. Note that the wire and part should never meet and there must always be a small gap. Furthermore, the level of dielectric fluid is another consideration. It must fill the gap area to prevent sparking.
- Programming and Computer Control
Most machines use a Computer Numerical Control (CNC) technology for precise control of the wire pathway. CNC wire EDM has a very high accuracy and is less prone to error. It is repeatable and creates high-quality cuts seamlessly. CNC wire EDM has a standard tolerance as low as +/- 0.001 inches.
Don’t overlook the power of correct programming in wire EDM. You must properly program a CNC wire EDM using the right software to get the best results. Examples of the most ideal CNC programming software available are SolidWorks, Meshcam, Fusion 360, and Master CAM. These software tools converts the CAD model into toolpaths. They tell the wire electrode how and where to move.
- Parameter Optimization
The different wire EDM parameters also determine the final result and overall productivity. You need to optimize the parameters based on what you want and the project requirements. These parameters include pulse duration, pulse interval, discharge current, and wire feed rate. A longer pulse duration allows the wire to melt and remove more material. However, it may compromise the final surface finish.
Make sure the interval between pulses is long enough to reduce heat build-up and extend the wire life. Additionally, consider lowering the discharge current and increasing the wire feed rate. This will reduce machining time and ensure efficient cutting.
- Workpiece Clamping and Positioning
When carrying out the wire EDM operation, you must secure the workpiece in place. There are different clamping mechanisms you can use with vises, fixtures, and chucks being the most common. They all prevent vibrations and unnecessary movements.
Vibrations can produce noticeable cutting marks and lead to a rough surface finish. Additionally, it wears out the wire and causes damage with time. Furthermore, proper clamping keeps workers safe and reduces the risk of injuries. The fixtures should provide adequate support to prevent the workpiece from flying around.
- Operator Training
The level of skill and training you have also determines the success of the operation. You must have hands-on experience and training to operate the machine safely and produce consistent results. Additionally, your programming skills should be superb. You must be familiar with the programming languages and be able to create programs for different designs.
With your knowledge, you will be able to optimize the cutting parameters based on the material and applications. Understanding safety protocols and controlling issues as they arise is also a must. Finally, you must stay up to date with the ever-evolving technology.
Conclusion
Wire EDM is a metal fabrication process that cuts conductive materials such as aluminum, steel, and titanium with a high degree of accuracy and precision. Though this technique produces consistent and repeatable results, it is important to know some tips and tricks for the best results. For an error-free operation, you must select the right material and adequately prepare the workpiece. The skill level of the operator is also important for proper programming and optimization of the parameters.