This technology is suitable when you need injection moulded parts quickly or at a lower cost. It is also great for low volumes or when you need to develop your production process. We can produce a mould of aluminium or soft steel with 10 to 20 days. This is the preferred process if you need between fifty to less than 10000 parts for testing or production. It is also a great way to optimize your injection moulding process before you commit to final tooling.
We use the same methods as used for hard tooling, only we use soft material like aluminium or soft steel, this declares why the lead times of soft tooling projects are shorter.
Computer Numerical Control (CNC) prototyping is a cutting process in which material is removed from a block by a rotating tool. In CNC milling the cutting tool is moved in all three or five (diagonal movement) dimensions to achieve the desired part shape. In CNC milling the cutting tool usually rotates about an axis that is perpendicular to the table that holds the material to be cut. A milling machine looks somewhat like a drill press at first glance. A cutting tool protrudes down from a rotating spindle. A block of material is placed on a moving table below the cutter. While the cutting tool turns, a computer controls the diagonal (Z axis) motion of the cutter and the horizontal and vertical (X and Y axis) motion of the block of material. The cutter is guided to move through the material, removing small portions to create the final shape.
CNC milling is the fastest method of making moulds, but the main disadvantage is you can’t mill straight corners, to make these corners we us an EDM Wire Machining.
Wire EDM machining (Electrical Discharge Machining) is an electro thermal production process in which a thin single-strand metal wire in conjunction with de-ionized water (used to conduct electricity) allows the wire to cut through metal by the use of heat from electrical sparks.
Due to the inherent properties of the process, wire EDM can easily machine complex parts and precision components out of hard conductive materials.
Wire EDM machining (also known as "spark EDM") works by creating an electrical discharge between the wire or electrode, & the workpiece. As the spark jumps across the gap, material is removed from both the workpiece & the electrode.
To stop the sparking process from shorting out, a non-conductive fluid or dielectric is also applied. The waste material is removed by the dielectric, and the process continues. This process allows the machinist to make difficult cuts on hard metal that would be nearly impossible with a CNC machine. Although the cutting may take longer, you will have less broken tooling as well as access to areas that would be unreachable with traditional methods of machining.
The sinker EDM machining (Electrical Discharge Machining) process uses an electrically charged electrode that is configured to a specific geometry to burn the geometry of the electrode into a metal component.
Two metal parts submerged in an insulating liquid that is connected to a source of current which is switched on and off automatically depending on the parameters set on the controller. When the current is switched on, an electric tension is created between the two metal parts.
If the two parts are brought together to within a fraction of an inch, the electrical tension is discharged and a spark jumps across. Where it strikes, the metal is heated up so much that it melts.
Innumerable such sparks spray, one after the other (never simultaneously) and gradually shape the desired form in the piece of metal, according to the shape of the electrode. Several hundred thousand sparks must fly per second before erosion takes place.