The waterjet, conceptually, is very similar to a plotter. Both devices have a flat surface on which to place the media, and a stylus that is moved in two programmable dimensions with an adjustable height control. The primary difference is that a cutting nozzle is being used as a stylus instead of an ink pen.

The waterjet system consists of two main categories of parts: first, the system which controls the movement of the cutting head (the motion system), and second, the system which creates the waterjet stream itself (the cutting system).

The Motion System

This is the system which takes as input a CAD drawing, and returns as output instructions for moving the cutting head automatically to produce a part. The process begins with a drawing of a two-dimensional path for the waterjet to cut. Using a CAD program, all extraneous information (such as dimension lines and text) is removed.

Commonly the customer will have a CAD file for the part they want to be cut, however, we can create such a file using either a dimensioned paper drawing, or measurements taken from a physical sample.

The Cutting System

The powerful half of the waterjet equation, the cutting system, is responsible for producing a coherent waterjet stream which is focused onto a location determined by the motion system.

An intensification pump is the basis of waterjet cutting. Water pressure is created by taking hydraulic pressure and intensifying it mechanically. On our links page you will find a link to the Ingersoll-Rand™ site, which contains more specific information on the waterjet process.

Once the water has been pressurized and leaves the pump, it connects to the cutting head, mounted on a gantry over the waterjet table, with a computer- controlled valve.

When the pressurized water is allowed to exit the valve, it is focused into the highly coherent, so named "waterjet"; first with a precious stone orifice (diamond, or sapphire), and second, with a carbide focusing tube (or nozzle), which is where it leaves the cutting head and penetrates the material. When using abrasive to cut hard material, which is our most common task, a line connected to the cutting head, draws in garnet (the same material bonded to many sandpapers) by Venturi Effect, and introduces it to the waterjet stream. The stream, with a pressure of approximately 55,000 psi, is now capable of cutting 6" thick steel, and more. This cutting method is known as micro-erosion, an extremely localized and focused process of erosion. Any material, with the exception of carbide and tempered glass (which cannot be cut after tempering by any method without fracturing), can be cut in this manner.