Sinker erosion machines, the first type of machine produced with EDM technology, are machines that remove chips by eroding the part with controllable sparks through electrical jumping. Slag is formed by melting due to the steam and temperature occurring on the eroded surface during the spark jump. This chip is removed from the environment through the EDM fluid. It is an electrothermal process performed via electrical discharge, without any mechanical cutting force seen in other machining techniques. Energy discharge is provided with controllable arcs. EDM machines where the amount of wear on the material and axial movements are fully controlled via arc are cnc sinker erosion machines.

High conductivity metals such as copper, tungsten, graphite, or alloyed electrodes are used as electrodes. The usage areas of the electrodes vary according to the targeted surface quality values. Other machining tools are needed for the preparation of the selected electrodes. Generally, materials that can resist high melting temperatures and wear, have good electrical conductivity, and are cheap are selected.

How Does Electrical Discharge Machining Occur? : The electrode, machined in various forms and shapes in CNC lathes or cnc machining centers, is fixed to the head of the sinker erosion. It is brought closer to the workpiece connected to the table of the tank filled with dielectric fluid. The dielectric fluid is non-conductive. The energy transfer from the power supply cards that provide power control within the machine is provided by special cables connected to the upper head. Energy is transmitted to the electrode connected to the upper head. It is brought closer to the material to be processed. At the shortest distance between the electrode and the material that can create an arc (this is called GAP in the electrical discharge process), the dielectric undergoes molecular breakdown and ionizes, and the discharge of the arc to the metal occurs. With the high dielectric pressure formed, a very high current passage occurs with the arc trapped in a small area. This causes very high temperatures both on the electrode and on the eroded surface on the workpiece, causing chips to break off in the form of evaporation and melting from both materials. With controllable current, the power is cut, the head moves up a bit, the excess chips move away from the environment and mix into the dielectric fluid, the power is automatically turned back on, the head approaches the material, and the cycle is repeated. In this way, the form of the electrode is transferred to the material.

Looking at the machine movements, since the sinking process will be in the + and - directions on the Z axis, the speed of X and Y axial movements is not very important. What matters is the precision of the surface obtained. Generally, the expected Ra surface roughness value is in the range of 0.2-0.3 microns. Therefore, there is no need for grinding the part produced in sinker erosion machines. In addition to these, with the linear motor technology used by the Japanese manufacturer Sodick in its own EDM machines, the sinking speed of the electrode into the workpiece has reached extremely high values. This has forced competing EDM manufacturers such as Agie, Charmilles, and Makino to carry their own technologies to much more advanced levels in terms of speed and precision.

ZNC Sinker Erosion type machines, which are one of the machines produced in the continuation of EDM technology, have different advantages from others; choosing this method if deemed appropriate will create efficiency. In this method, the spindle uses a ball screw that increases quality and accuracy. A DC servo is used in the use of the ball screw. The table used is subjected to a high-frequency hardening and annealing process, then polished with a grinder to ensure long use. To detail the advantages we mentioned; the existing cast bench has a very hard and fine-grained surface. There are columns and a table, this bench provides true stabilization and facilitates long-lasting use. Process features can be changed while the machine continues to work; this situation provides a considerable advantage in cases requiring sudden intervention. These types of benches generally have spark prevention functions.

CNC Sinker Erosions are a non-traditional production process and are used to obtain the negative impression of the electrode on the workpiece. Machining is done in a dielectric submerged state. Generally, the machining electrode is Copper and Graphite, and the workpiece is selected from a conductive material or its alloys. Today, most sinking CNC Sinker Erosion applications require multiple passes to obtain the desired accuracy and surface quality in the processed parts. It is done by applying a combination of different processing parameters such as current, voltage, discharge, on / off time, etc., which are controlled fully automatically by the computer with the help of a pre-determined conditions database. All axes of these CNC Sinker Erosion machines are programmable and operate automatically. It can provide fast production; as a different advantage, it can be said that the electrodes wear slowly. The surface quality is high, and a near-smooth result can be obtained. Talking about other advantages; it provides great convenience in the production of complex shapes that are difficult in common production methods. Even when working on hard materials, the resulting surface quality is near-smooth, and it can be used smoothly in the processing of hard materials. Tools do not come into direct contact with the processed part, so the part is not damaged or distorted in the production of sensitive parts. In addition, even very small diameter holes can be opened on the part to be produced. Due to these advantages, it has become one of the CNC machines that have started to become widespread today.

Information : In Sinker Erosion machines, if the electrode touches the material, a short circuit occurs and the machine goes into an alarm.

What tasks are Sinker Erosions used for? : Let's imagine a square that we want to have sharp corners instead of radiused ones. It is not possible for us to do this by emptying it in the form of engraving in metal material with a milling or cnc machining center. However, if we machine a sharp-edged male square form onto an electrode, we can easily achieve the desired result by sinking into the part in this way.

Under the sinker erosion machines category, there are listings and prices for pre-owned and new edm sellers, and second hand for sale nc and cnc sinker erosion machines from owner.