EDM Wire Cutting Machines: Advantages & Disadvantages Explained

A wire cut machine is a non-traditional high-precision machine tool. In this process, typical conductive material workpieces have characteristics that are formed by controlled corrosion of materials using electric sparks. The core of electrical discharge machining is two electrodes, which are separated by a dielectric fluid, usually deionized water or oil. When the field strength between the two electrodes is high enough, the dielectric breaks down, current flows, and material is removed from the two electrodes. The current between the electrodes is unstable. Instead, debris is generated instantly, which will be washed away by the fluid. This operation can be performed repeatedly to erode the finely controlled function, which cannot be created using traditional machining methods. Let’s talk about some of the big advantages of using a wire cutting machine and also some of the drawbacks you should consider.

 

EDM Wire Cut Machine – Pros

In short:

• Complex shapes difficult to create with conventional cutting tools
• No direct contact between tool and workpiece allowing for machining of sensitive materials and intricate part areas without distortion
• Suitable for extremely hard and challenging materials with very strict tolerances which is important for the manufacture of high precision components almost no polishing required after machining
• Good for relatively small workpieces, where conventional cutting tools would damage them due to the high cutting tool pressure

In more detail:

With a wire-cut electric discharge machine, you can release a controlled and fast repetitive charge to remove material from conductive materials. For the right application, this is a very precise method, such as two-axis cutting with small tolerances in small batches. For example, for mass production of pins, probes, and other small solid metal parts with a diameter of less than 0.50 mm, a wire cut machine can provide: highly repeatable lengths without end deformation, deformation, or splitting floor. It is more cost-effective than methods such as laser cutting. For small diameter solids, wire-cut electrical discharge machining can also provide extremely high central tendency measurement values ​​to significantly increase the Ppk / Cpk value. An EDM wire cut machine can cut diameters ranging from a few thousandths of an inch to a few inches, and a length ranging from 12 mm to 450 mm and has outstanding accuracy when it comes to dimensions. Since there are no grinding wheels or saw teeth involved, processing with a wire cut machine usually does not leave any burrs, and the cut width is usually 0.1 to 0.3 mm. EDM wire cut machine operations can also fairly quickly decrease the hardness of conductive metals, from copper to the hardest ones, including molybdenum and tungsten. EDM also offers a normal radius to end cut; depending on the case, this can or may not be a benefit.

 

EDM Wire Cut Machine – Cons

In short:

• Slow removal speed
• Electrodes for Ram/Sink EDMs create additional costs and are time-consuming
• Electrode wear makes reproduction of sharp corners difficult 

In more detail:

The most widely recorded negative effect is that an EDM wire cut machine is still a very slow process. To help reduce slow cutting speeds, modern wire cut machines with Automatic Wire Threading and CNC functions can be programmed to "light off." However, it is best to employ a method such as thin-wheel abrasive cutting for a large number of parts with a diameter greater than 0.5 mm. This technique is limited to conductive materials due to the existence of wire cutting machines — the elimination of material by quickly reusing controlled charges around the bundle of metal wire. And any plastic or dielectric-coated material is not appropriate for an EDM wire cut machine.

The repeated discharge of the welding wire heats the target area of ​​the workpiece to thousands of degrees. This may cause thermal stress on adjacent parts and cause a certain amount of waste. The welding wire itself is also damaged, so the EDM wire cut machine must continuously deliver new welding wire. Another downside to wire cutting machines is the creation of an oxide layer on the cut sheet, depending on the wire to be sliced. This could require a second washing, which would increase costs. Wire cutting is ideally suited for solid materials, so this approach is not suitable for wire cutting. The pieces cut by EDM must be securely fixed in order to maintain the conductivity. This causes a high risk of deformation. This will also cause the cutting line to touch the workpiece, to short-circuit the cutting, to interrupt the cutting line, and to cause a phase on the workpiece. Although you can fix a test tube to rotate it in a wire cut machine, this method has been optimized for more complex shapes and is not efficient for simple 2-axis pipe cutting.

Besides, the EDM method cannot cut short cuts below 3.175 mm, nor can it produce high-quality cut end surface finishes. Actually, a wire cutting machine can cause surface roughness, which is sometimes jokingly compared to the moon craters. Therefore, methods such as thin-wheel abrasive cutting can have the requisite of close tolerances, burr-free results. This is also true for clean end faces with no pipe wall deformation during cutting applications such as medical device tubes which have to be cut too short lengths and have a very smooth end finish.

 

With a Wire Cut Machine, the Possibilities can be Endless

So as we have seen, wire cutting machines and their precision cutting methods that may be considered have many pros and cons. So, is a wire cut machine suitable for your small part cutting application? It depends. This is because the effectiveness of any cutting method can vary greatly depending on the materials you use and the desired results. Choosing the right EDM wire cut machine requires an in-depth understanding of your application, its parameters, and the end-use of the product.

 

Wire Cutting Machines on IMTS-Exhibition.com

You can find many wire cut machines from many different manufacturers on our site. Just head to our product section or check out our search function to find hundreds of companies in our product database. If you want to learn more about EDM wire cut machine related questions and applications make sure to check out our other blog entries. If you are interested in even more detailed manufacturing-related content make sure to check out our MTS Industry Channel. In this show, we introduce new products and trends and visiting manufacturers in their production plants!

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