We offer rapid prototyping services for all custom products. The turn-around time is 5 business days with the exception of parts with extremely complex geometries. For urgent tasks, we can produce prototypes in the same or next day. The methods used in making prototypes include CNC machining, wire EDM, sinker EDM and water-jet cutting.
CNC machining is the most versatile process that can produce a wide range of products with almost any metal or plastic materials. The advantages of CNC machining include its dimensional accuracy, repeatability, speed and simplicity. Although the cost of CNC machining is slowly coming down, it is still expensive to use CNC machining in high volume productions.
In wire EDM (electrical-discharge machining), a slowly moving wire travels along a prescribed path, cutting the workpiece, with the discharge sparks acting like saw teeth. Wire EDM offers short delivery time since no tooling is required. The process leaves very little residual stress on the workpiece as opposed to CNC machining, and therefore little change on mechanical property is expected. With the right machine and setup, wire EDM can also make angled cuts or cuts that result in different profiles on the top and bottom. The disadvantages of sinker EDM include the slow rate of material removal and the high electricity consumption.
In sinker EDM, an electrode is machined into the desired shape and fed into the workpiece in an insulating liquid. The power supply generates an electrical potential between the electrode and the workpiece. As the electrode approaches the workpiece, dielectric breakdown occurs and a huge number of sparks happen and erode the workpiece into the desired shape. Compared with CNC machining, sinker EDM can produce even more complex shapes, such as deep and narrow small cavities, sharp corners, narrow seams and deep holes, which are extremely difficult to produce with conventional cutting tools. With sinker EDM, good surface finish and close tolerance can be achieved. The disadvantages of sinker EDM include the slow rate of material removal, extra time and cost for creating the electrodes, and the high electricity consumption.
In water-jet cutting, a combination of water and abrasive material is pressurized and forced through a nozzle to the workpiece. Water-jet cutting offers short delivery time, as no tooling is required and secondary finishing is not necessary. Water-jet cutting also holds good tolerance, leaves no heat affected zones on the workpiece and results in parts with good mechanical properties. The disadvantages of water-jet cutting are the process can be expensive for some materials and tapers may be formed when the workpiece is thick.