Professional Guide to EDM Drilling Machines – Precision & Efficiency

 

Overview

An EDM drilling machine is a machine tool primarily used for making a small hole or driving fasteners. An EDM drilling machine is used for the drilling process, and it is also the processing technology often required in manufacturing production. There are a variety of different kinds of EDM machines on the market, and in this article, we are going to tell you a bit about EDM drilling machines.

 

How Does EDM Drilling Machine Work

EDM drilling machines operate much like any other process that utilizes EDM. The only difference is that the EDM drilling machine is optimized to create semi-accurate small holes in ductile materials high speeds regardless of how hard the material is.

When an EDM Drilling machine is in action, material is removed from the work object by a series of rapidly recurring current discharges between two electrodes, separated by a dielectric liquid and subject to an electric voltage. One of the electrodes is referred to as the “tool electrode”, or simply known as the tool or electrode, while the other is called the “workpiece electrode, or simply known as work piece. The EDM process depends upon the work piece and tool not making physical contact.

In EDM hole drilling, the dielectric is required to wash away the electrode particles from the cut, the flushing liquid would have to be delivered to the very bottom of the hole being cut in order to achieve this. In this case, a drilling electrode is required that has a tube to allow the fluid to pass the electrode easily and consistently.

 

Application of EDM Drilling Machine

EDM hole drilling is used in a variety of applications. First and foremost, EDM drilling machine is used to drill rows of small holes into both the leading and trailing edges of turbine blades used in jet engines. Gas will flow through the small rows of holes, allowing the engines to utilize high temperatures. The high temperature, hard and single crystals are deployed into these blades, making conventional machining of these wholes with high aspect ratio extremely difficult, if possible.

EDM drilling machine is also utilized to create microscopic orifices for fuel system components, spinnerets for synthetic fiber like rayon, and other applications. Some stand-alone models with X and Y axes are even able to machine blind or through holes, commonly known as the super drill.

EDM drilling machines drill bore holes with a long copper tube electrode that rotates in a chuck with a constant flow of deionized water flowing through the electrode as a dielectric or flushing agent. They are capable of drilling through 100 mm of hard steel in less than ten seconds, average a 50% to 80% wear rate. Holes as small as 0.3 mm can be achieved with such drilling operation.

Although brass electrodes are easier to machine, they are generally not recommended for wire cut operations due to eroded brass particles causing wire breakage.

 

Advantages of EDM Drilling Machine

Some of the advantages of EDM drilling machines include:

• EDM drilling machines are able to machine work pieces that are complex or irregularly shaped which would otherwise be difficult to produce with conventional cutting.
• EDM drilling machines are able to machine extremely hard material to very close tolerances.
• EDM drilling machines are able to drill small holes on extremely small work pieces where conventional cutting tools may damage the part form excess cutting force.
• There is no direct contact between the tool of EDM drilling machine and the work piece. Therefore, delicate section and weaker materials can be machined without perceivable distortion.
• Even though you are drilling holes on a work piece, a good surface finish can be achieved. A very decent surface can be acquired by redundant finishing paths.
• Very fine holes can be attained by using EDM drilling machine.

 

Disadvantages of EDM Drilling Machine

Some of the drawbacks of EDM drilling machines include:

• It is difficult to find an expert machinist to operate and manage an EDM drilling machine.
• The rate at which the work material is removed is very slow.
• Using EDM drilling machine can pose potential fire hazard associated with the use of combustible oil-based dielectrics.
• It can be very time-consuming and costly to create electrodes for the EDM process.
• It is difficult to reproduce sharp corners on the work piece because of the electrode wear.
• The specific power consumption of EDM drilling machine is extremely high, which in turn lead to higher utility and maintenance cost.
• The power consumption of an EDM drilling machine in general is very high as well.
• You’ll notice that the tool of EDM drilling machine will wear in a fast and excessive manner as opposed to other manufacturing machinery.
• EDM drilling machines with specific set-up may be required to machine electrically non-conductive materials.